^^i! mt BULLETIN OF THE DEPAETMENT OF AGEICUETUEE, TEINIDAD AND TOBAGO. Issued hy the Department and the Board of Agriculture. VOLUME XVIII, 1919. Editorial Committee. W. G. Freemax, B.Sc, A.R.C.S., F.L.S., Director of Agriculture. F. W. Urich, F.E.S., C.M.Z.S., Ent07nologisf, Board of Agriculture. J. deVerteuil, F.I.C, F.C.S., Superintendent of Field Experiments, Editor : W. G. Freeman. TEINIDAD! Printed at the Government] Printing Office, PoRT-or-SPAiiJ. .u. ^/^ ^./f 11. DEPARTMENT OF AORICULTURE. Head Office. Director W. G. Freeman, B.Sc. (Lond.),A.R.C.S.,F.L.S. Assistant Director {Acting) and | j_ ^^ Verteuil, FJ.C, F.C.S. Superinte7ident of Field Experiments] Asst. Superintendent Field Experiments L. A. Brunton. Officer in Charge of Special Investigations... K. E. Collens, F.I.C, F.C.S.-'- Chief Clcrh .Jos. E. Seheult. Clerls M. Dhein, A. Hosein, Botanical Department. Government Botanist W. G. Freeman, B.Sc. (LoncL), A.E.C.S., F.L.S. Curator, Boy al Botanic Gardens, Ac R. 0. Williams. Horticulturist and Asst. Botanist W.E.Broadway. Officer in Charge of Botanic Station, Tobago B. J- Link. Clerk F. Chookolingo. Herbarium Assistant... W\&^ V. McLean. Overseer (Trinidad).... J. Finder. Foreman (Tobago). ...-J. Blackman. Government Laboratory. Government Analyst {kcting) H. S. Shrewsbury, F.I.C, F.C.S. ( J. DE Verteuil, F.I.C, F.C.S. Assistant Analysts | ^ ^^ Collens, F.I.C, F.C.S.* Clerical Assistant S. M. Oarrmuddeen. Government Farms. Manager J. McInroy, Manager (Tobago) R. J. Link. Overseer and Clerk (Trinidad) St. Augustine'Estate. Manager J- McInroy. Overseer H. Lyndon Kerr. Clerk A. P. Daly. River Estate. Superintendent L. Seheult, B. Sc, (Edin.) Manager R. O'Connor. * Acting temporarily as Government Chemist and Superintendent of Agriculture for the Leeward Islands. Froghopper Investigations. Special Appointment. C B. Williams, M.A. (Camb.) F.E.S. Ul. Date of Eegistration. .October 12, 1916. DEPARTMENT OF AGRICULTURE. Agricultural Credit Societies under Ordinance No. 30, 1915. Begistrar W. G. Freeman, Director of Agriculture. hispector.. Jos. E. Seheult. Registered Societies Trinidad, Diego Martin Lothians Malgretout ... Petit Morne ... Union Hall ... Malgretout East Indian ... Picton Petit Morne (Palmyra) ... Tarouba (Ne Plus Ultra) Union-Marabella Harmony Hall Williarasville East Indian Indian Walk... "Williamsville West Indian Plein Palais ... Lengua Penal Tohago. Pembroke Scarborough ... Delaford Mason Hall ... Moriah Charlotteville ...April ...April ...April ...April ...May ...May ...June ...June ...July ...July ...July ...August 4, 1919. 30, 1919. 30, 1919. 30, 1919. 26, 1919. 30, 1919. 13, 1919. 13, 1919. 10, 1919. 10, 1919. 10, 1919. 19, 1919. ...September 11, 1919. ...November 9, 1919, ...November 9, 1919. ...November 21, 1919. ...June 18, 1917. ...April 11, 1918. ...August 26, 1918. ...December 16, 1918. ...December 16, 1918. ...February 4, 1919, Plant Protection Ordinance. Chief Ijispector (Acting) W. E. Broadway. IF. W. Urich. Ifupectors. Assistant Inspectors. R. O. Williams. H. Meaden. ,L. A. Brunton. J. A. PiNDEE. J. Blackman. R. W. Leacock. .Alfred H. Pena (Tempy.) Reference Library. This Library can be consulted at the Head Office of the Department, St. Clair Experiment Station. It contains standard works on General Agriculture, Horticulture, Botany, etc., and books and periodicals dealing with Cacao, Sugar, Coconuts, Rubber, Cotton, Corn, Fruit, Tobacco, and other crops. IV. BOARD OP AG-RICULTURE. President His Excellency the Governor. Vice-President The Director of Agriculture. Hon. Sir Norman Lamont, Bt. „ Sii- G. Townsend Fenwick, K.C.M.G. „ C, DE VeRTEUIL. „ AV. G. Kay, O.B.E. „ E. S. A. Warner, K.C. J. W. Arbuckle. J. P. Bain. J. Black. A. B. Carr. Joseph d'Abadie. L. DE Verteuil. W. Greig. W. C. Jardine. J. J. McLeod. C. S. Kogers. C. F. Todd. W. S. E. Barnardo. J. J. A. Carleb. Acting Assistant Director of Agriculture. Mycologist J. B. Rorer, M.A. Entomologist F. W. Urich, F.E.S., C.M.Z.S. Secretary Jos. E. Seheult. ^F. D. Davies, Tobago. Agricultural Advisers -'|C. M. Roach, San Fernando. IL. Mota, Rio Clara. Laboratory and Field Assistant W. Buthn. Standing Committees. By the rules of the Board, the Mycologist is a member of all Standing Committees. Advisory Committee. —This consists of all the members of the Board ; five as a Quorum. FiXANt.'E Committee. — The Director of Agriculture, Hon. Sir. G. Townsend Fenwick, K.C.M.G., Hon. Carl de Verteuil, Messrs. Wm. Greig, J. J. McLeod and A. B. Carr. Cacao Committee. — The Director of Agriculture, Messrs. J. d'Abadie, Ludovic de Verteuil, J. P. Bain, A. B. Carr, W. C. Jardine and W. S. E. Barnardo. Sugar Committee. — The Director of Agriculture, Hon. Sir Norman Lamont, Bt., Hon. Sir G. Townsend Fenwick, K.C.M.G., Hon. W. G. Kay, O.B.E., Messrs. C. Forbes Todd, J. Black, J. J. McLeod and J. W. Arbuckle. Rubber Committee. — Tlie Director of Agriculture, Hon. Sir Norman Lamont, Bt., Hon. R. S. A. Warner, K.C, Messrs. C. S. Rogers and Wm. Greig. Government Farm Advisory Committee. — The Director of Agriculture, Messrs. J. W. Arbuckle, J. J. McLeod, J. Black, C. Forbes Todd and Dr. J, Duncan Miller. Statistics Committee. — The Director of Agriculture, Hon. Sir Norman Lamont, Bt., Hon. Sir G. Townsend Fenwick, K.C.M.G., Messrs. W. C. Jardine, Wm. Greig, A. B. Carr. Agricultural Exhibition Committee. — The Director of Agriculture, Hon. Sir G. Townsend Fenwick, K.C.M.G,, Hon. W. G. Kay, O.B.E. and Mr. Ludovic de Verteuil. LIST OF PLATES. Facing Page. Wither Tip Disease of Lime ... ... ... I Rose Leaf Spots ... .. ... ... 29 Rose Mildew ... ... ... ... ... 29 Cacao Thrips (Figs. 1-16). Avocado in Trinidad and Tobago (Figs. 1-5). Insects affecting the Avocado (Figs. 1-5). Fungous Diseases of the Avocado ... ... ... 133 Rainfall and Froghopper Blight (Figs. 1-11). Root Disease of Cacao, Bosellinia Fejpo (Figs. 1-5) ... 180, &c. Part 1.] [Vol. XVIII. BULLETIN OF THE DEPAETMENT OF AGEICULTUEE, TEINIDAD & TOBAGO. Issued bif the Department and Board of Agricidture Editorial Committee. W.G. Freeman, B.Sc. A.R.C.S., F.L.S., Director of Agriculture (Acting). F. W. Urich, F.E.S., C.M.Z.S., Entomologist, Board of Agriculture. J. DE Verteuil, F.I.C, Y.C.S., Superintendent of Field Experiments. Editor : W. G. Freeman. \ TRINIDAD : Printed at the Government Printing Office, Port-of Spain. Price : Six Pence. / 111. DEPARTMENT OF AGRICULTURE. — _ (j. Head Office. Director (Acting) W. G. Freeman, B.Sc. (LoncL), A.E.C.S., F.L.S. Assistant Director (Acting) and _ I J. de Verteuil,F.I.C., F.C.S. Superintendent of Field E xper^ments } Asst. Superintendent, Field Experiments L. A. Brunton. Officer in Charge of Special Investigatio7is.. .A.'E. Collens, F.I.C, F.C.S. •'= Chief Cleric Jos. E. Seheult. Clerics M. Dhein, A. Hosein. Botanical Department. Government Botanist W. G. Freeman, B.Sc, (Lond.), A.R.C.S., F.L.S. Superintendent, Royal Botanic Gardens, dx. (Acting). ..R. 0. Williams. Horticulturist and Asst. Botanist W. E. Broadway. Officer in Charge of Botanic Station, Tobago H. Meaden. Cleric F. Chookolingo. Herbarium Assistant— Miss P. McLean. Overseer (Trinidad)...!. Finder. Foreman (Tobago) J. Blackman. Government Laboratory. Government Analyst (Acting)... H. S. Shrewsbury; F.I.C, F.C.S. (J. DE Verteuil, F.I.C, F.C.S. Assistant Analysts -^^_ -^^ Collens, F.I.C, F.C.S.- Laboratory Assistatit... (Tem-poravy) E. J. Sankeralli. Clerical Assistant S. M. Carrmuddeen, Government Farms- Manager J. McInroy. Manager (Tobago) H. Meaden. Overseer (Acting) (Trinidad) H. Lyndon Kerk. Cleric (Acting) ^ A. P. Daly. St- Augustine Estate- Manager J- McInroy. Overseer H. Lyndon Kerr. Cleric A. P. Daly River Estate. Superintendent - J- de Verteuil, F.LC, F.C.S. Manager (Acting). L. Seheult, B. Sc.,(Edin.) * Acting temporarily as Government Chemist and Superintendent of Agriculture for the Leeward Islands. o) Officers on Active Service- Pw O'Connor Manager Eiver Estate. R. J. Link Overseer and Clerk, Govt. Farm, Trinidad. ]V. DEPARTMENT OF AGRICULTURE. Agricultural Credit Societies under Ordinance No. 30, 1915. Registrar. Inspector.. .W. G. Freeman, Director of Agriculture (Acting). .Jos. E. Seheult. Trinidad. Diego Martin Lothian s Malj^retout ... Petit Morne ... Union Hall ... Tohago. Ppmbroke ... Scarborough Delaford Mason Hall... Moriah Charlotte ville Registered Socilties. Date of Registration. . October 12, 1916. .. April 4, 1919. .. April 30, 1919. .. April 30, 1919. ., April 30, 1919 .. .June 18, 1917 .. April 11, 1918 .. August 26, 1918 .. December 16, 1918 .. December 16, 1918 .. February 4, 1919 Plant Protection Ordinance- Chief Inspector (Acting) W. E. Broadway. ,r. W. Urich. Inspectors ! ^- O- Williams. "jH. Meaden. (L. a. Bkunton. ij. A. PiNDER. Assistant Inspectors •,' J. Bl.ackman. lE. H. Leacock (Actg.) Froghopper Investigations- Special Api) ointment. C. B. Williams, M.A., (Camb.) F.E.S. Reference Library. This Library can be consulted at the Head Office of the Department, St. Clair Experiment Station. It contains standard woi'ks on General Agriculture, Horticulture, Botany, etc., and books and periodicals dealing with Cacao, Sugar, Coconuts, Rubber, Cotton, Corn, Fruit, Tobacco, and other crops. BOARD OF ACirRICULTURE. President His Excellency the Governor. Vice-President The Director of Agriculture. Hon. Sir Norman Lamont, Bt. „ Sir G. Townsend Fenwick, K.C.M.G. „ C. de Verteuil. „ W. G. K.vY. „ R. S. A. Warner, K.C. J. ^Y. Arbuckle. •T. P. Bain. J. Black. A. B. Carr. Joseph d'Abadie. L. de Verteuil. W. Greig. W. C. Jardine. J. J. McLeod. C. S. Rogers. C. F. Todd. J. Duncan Miller, M.R.C.V.S. W. S. E. Barnardo. J. J. Carlee. Acting Assistant Director of Agriculture. Mycologist T. B. Rorer, M.A. * EntomolcgUt F. W. Urich, F.E.S., C.M.Z.S. Secretary Jos. E. Sehkclt. [F. D. Davies, Tobago. Agricultural Advisers ]c. M. Roach, San Fernando. (l. Mota, Rio Claro. Laboratory and Field Assistant W. Buthn. * On leave for a year from December, 1918. Standing Committees. Advisory Committee.— This consists of all the members of the Board ; five as a Quorum. Fixaxce Committee. —The Director of Agriculture, Hon. Sir G. Townsend Fenwick, K.C.M.G., Hon. Carl de Verteuil, Messrs. Wm. Greig, J. J. McLeod and A. B. Carr. Cacao Committee.— The Director of Agriculture, Messrs. J. d'Abadie, Ludovie de Verteuil, J. P. Bain, A. B. Carr, W. C. Jardine and W. S. E. Barnardo. SrnAR Committee. — The Director of Agriculture, Hon. Sir Norman Lamont, Bt., Hon. Sir G. T(jwnsend FenM^ick, K.C.M.G., Hon. W. G. Kay, Messrs. C. Forbes Todd, J. Black, J. J. McLeod and J. W. Arbuckle. Rubber Committee.— The Director of Agriculture, Hon. Sir Norman Lamont, Bt., Hon. R. S. A. Warner, K.C, Messrs. C. S.Rogers and Wm. Greig. Government Farm Advisory Committee. — The Director of Agriculture, Messrs. J. W. Arbuckle, J. J. McLeod, J. Black, C. Forbes Todd and Statistics Committee. — The Director of Agriculture, Hon. Sir Norman Lamont, Bt., Hon. Sir G. Townsend Fenwick, K.C.M.G., Messrs. W. C. Jardine, Wm. Greig, A. B. Carr. Agricultural Exhibition Committee.— The Director of Agriculture, Hon. Sir G. Townsend Fenwick, K.C.M.G., Hon. W. G. Kay, and Mr. Ludovie de Veiteuil. VI Department of Agriculture. GOVERNMENT STUD ANIMALS. The following are the arrangements for May and June with regard to Stud animals of the Government Farms in Trinidad and Tobago. Name. Class. Stallions. Where standing for Service. ■QuiCKMATCH. Thorough-bred ...Govt. Farm Trinidad... Sir HoRRY...Thor'gh-bred Hackney.. Govt. Farm „ Sir HoRACE..Half-bred Hackney .."...Govt. Farm „ EiLLiNGTON SPARTAN..Cleveland Bay..Picton Estate, San F'do Maeat ...Thorough-bred ...Bon Accord, Tobago ... Fee. « 10.00 5.00 5.00 5.00 4.80 Groom's Fee. 60c. 60c. 60c. 60c. 60c. Jack Donkeys. Monarch ...American Donkey ... WilJiamsville ... $ 5.00 President ... Do. do. " ...Govt. Farm, Tobago... 5.00 Barbados Joe.Jack Donkey ...Brechin Castle Est., Couva. 60c. 60c. A.- TRINIDAD. <~ Bulls. -At Goverjiment Farms. Clafts. 2 Pure-bred Zebu 1 ,, .Jersev 2 Half-bred Red Poll Fee. « 1.20c. 2.40c. ] .20c. TOBAGO. Class. Pure-bred Shorthorn Pure-bred Zebu Half-bred Guernsey Fee. ...$2.40 ... 1.00 ... 1.00 B Place. Queen's Park Savannah Mucurapo Pasture St. Augustine Estate River Estate San Fernando Harmony Hall Estate Arima Tobago, Friendship Est. At Public Pastures or Estates. Class. 1 Half-bred Shorthorn ; 1 Half-bred Shorthorn ; 2 Half-bred Holstein ; 1 Half-bred Zebu ; 1 Pure-bred Holstein ; 1 Pure-bred Shorthorn. 1 Half-bred Jersey. 1 Half-bred Holstein. Pigs. 1 Half-bred Holstein. 1 Half-bred Guernsey, 1 Half-bred Guernsey. 1 Half-bred Jersey. At Government Farm, Trinidad. White Yorkshire, Berkshire, Tamvvoi-th Attendant's Fee 25c.. Berkshire At Government Farm, Tobago. ...Fee 51.00; ...Fee 50c. POULTRY. Government Farm, Trinidad. Eggs of Barred Plymouth Rocks, Black Minorcas, Brahmas (light), Rhode Island Reds, White Leghorns $1.00 per doz. Great Kind Pigeons ... ... 40c. and 60c. per pair. Government Farm, Tobago. Eggs of Plymouth Rocks, Black Minorcas, Rhode Island Reds 48c. per doz. Also Cocks and Pullets of Plymouth Rocks and Rhode Island Reds. Vll, Department of Agriculture. NURSERY STOCK. Orders for Oranges, Grape .Fruit, and Grafted Mangos for this year should be sent in without delay addressed to the Acting Superintendent, St. Clair Experiment Station, or to the Officer in Charge Botanic Station, Tobago. Special quotations at St. Clan- for Cacao, Coffee and Limes grown from selected seeds are as follows : — Plants purchased in lots of 1 to 1,000 plants v 3 cents per plant. I Delivered at Nurseries Plants pm-chased in lots of several thousands uncrated. 2^ cents per plant. ' Plants purchased in lots up to 100 at 4 cents "j per plant. Plants purchased in lots up to- 1,000 at $3.50 per 100. Plants purchased in lots of several thousands at 133.00 per 1,000. Tobago prices on application at the Botanic Station, Scarborough. Budded Avocados select varieties at 12 cents, Budded Oranges at 24 cents and Grafted Mangos at 24 cents should also be booked at once. Budded Cacao 12 cents each or in lots of over 100 at 8 cents. Limes from beds IJ cents per plant for lots over 100. A select stock is also kept of other fruit, ornamental and flowering trees, palms, etc., a list of which can be obtained on application. Large orders must be booked six months previous to the date when the plants are required as large supplies are not kept on hand for casual demands. Delivered at Railway Station, Port - of- Spain or Queen's Wharf, securely packed in open crates. Board of Agriculture. SPRAYING CACAO, &c. From September to November is the time for spraying cacao treea for the prevention of thrips and black rot ; and early in the dry season for the Algal disease, die back, and cacao beetles. The Board of Agriculture has on hand a supply of bluestone, which is sold to planters at 14^ cents per pound, also nicotine sulphate the best insecticide' for thrips, which is sold at $10.70 per gallon. Men will be provided to superintend any spraying work which estates may wish to have done. . Further information in regard to cost of spraying, etc., and applica- tions for bluestone and nicotine sulphate should be made to The SECRIiTARY, Board of Agriculture, Port-of- Spain. vm. PUBLICATIONS FOR SALE. Thk Bulletin issued quarterly, price sixpence per number, or two shillings per annum post free in the Colony. To other subscribers postage extra. Part 1. 191S. — Keport on St. Lucia Lime Factory. Storage of Black-eye Peas (Illustrated) ; Fruits of Trinidad and Tobago ; Uses and culture of Dasheens (Illustrated), Prize Competition Reports; etc., etc. Part 2. 1918. — Coffea excelsa ; Yam cultivation ; Insects affecting Vegetables ; P^ubber Tapping Experiments ; Tobago Orchids, etc. Part 3. 1918. — Agricultural Co-operation in the West Indies; Agri- cultui'al Credit Societies ; Sugar Cane Experiments ; Trinidad Thrips, etc., etc., etc. Part 4. iPiS.— Cassava Experiments 1916-18. Food of the Mon- goose. Eats and Mongoose. Strongylus in Cattle, Sheep, Goats, &c. Our Local Foods : Their Production and Use, by W. G. Freeman, and R. 0. "Williams.— Price 3d. The Dasheex : Its Uses and Cultm-e. — Illustrated. — Price 3d. Insects Affecting Vegetables in Trinidad and Tobago, by F. W. Urich. Symptoms of pests. Treatment, Preparation of Insecticides, etc. — Illustrated. — Price od. Life History and Control of the Cacao Beetle, 3 coloured plates, by P. L. Guppy.— Price 6d. Insect Notes for 1910-11. Miscellaneous Notes on Cacao Pests, by F. W. Urich.— Price 3d. Notes on some Insects affecting the Coconut Palm, one coloured plate by F. AV. Urich and P. L. Guppy. — Price 3d. The Cotton Stainer Bug (Illustrated), by P. L. Guppy and Thomas Thornton. — Price 3d. Rearing of the Vermilion Froghopper Egg Parasite, by F. W. Urich.— Price Id. The Sugar Cane Froghopper, six plates (3 coloured), by F. W. Urich. — Price 9d. The Surinam Witch-Broom Disea.se of Cacao, by J. B. Rorer. — Price 3d. The Froghopper Egg Parasite and its Colonization in Cane Fields, by F. W. Urich.— Price Id. Thi:; Mongoose in Trinidad and methods of destroying it, 2 plates, by F. W. Urich.— Price 3d. Annual Reports, Department of Agriculture, 1916 and 1917.— Price Is. 9d. each. All publications can be obtained from the Head Office of the Depart- ment, St. Clair Experiment Station, and sent post free within the Colony. The Bulletin is also on sale at Messrs. Muir, Marshall, and Davidson & Todd, Port-of-Spain. OF THE DEPAHTISIENT OF AGmiOULTTTJaE Trinidad, and Tobag-o. Part 1.] [Vol. XVIII. LIMES THE WITHER-TIP OF LIMES. Bi' James Birch Borer, Mycologist, Board of Agriculture. With One Plate. During July and August, 1918 there was a severe outbreak of a disease of lime trees throughout the colony, practically all districts being equally affected. Specimens were received from a large number of different estates, and all showed " wither-tip " in its characteristic form. This is one of the commonest and most destructive diseases of limes, though heretofore, it has not been very prevalent in Trinidad. It is due to the fungus known as Qloesporium limetticolum, Clausen. The fungus is able to attack the young growth of lime plants of all ages ; in fact, at the St. Clair Experiment Station it has caused the death of a great many nursery plants of from six inches to a foot high, during the past two years, (i) APPEAEANCE OF THE DISEASE. The attacks of the fungus generally show on the tips and edges of the very young leaves, but they affect also the leaf stalk, at the point where the leaf joins the stem, or any point in the very young shoots. The first sign of infection is indicated by a somewhat' water-soaked appearance until the young leaves and tip of the shoot are entirely destroyed. If the weather is not so damp, the water-soaked appearance is not so pronounced, but the attacked part is light green in colour at first, and then become brown. In all cases, the affected shoots wither up, thus giving the popular name of the disease. When the larger young leaves are affected they often become carled and distorted and the infected areas drop out or become cracked, so that the leaf is punctured with holes. Only young growing leaves and the young shoots apparently can be attacked by the fungus; leaves and shoots that have become hardened and matured are quite immune to the disease. (1.) This disease musb not be confused with the " Damping-off " disease which is very severe on seedlings when the}' are from one to three inches high, and which has already been described in the Proceedings of the Agricultural Society, KV, 1915, 14-15, " "Wither-tip " generally attacks the plants when they are a little older. 2 TBINIDAD AND TOBAGO BULLETIN. [XVIIL 1. In addition to the leaves and the tender shoots, the flowers (i) and young fruit are very susceptible to attack, and on this account, the disease causes a great loss of fruit. If the flowers are attacked, they fall from the tree without setting fruit. When young fruits are attacked, they show a rough scaby appearance and become cracked, and generally fall from the tree in two or three weeks. After the fruits have become half-grown, they seem to be immune to further attack. Full-grown fruits, after having fallen to the ground, however, may be attacked through wounds, and the fungus in this way, probably causes a good of rotting of the fruit from the time of gathering until it reaches the factory. TREATMENT OF THE DISEASE. As this disease became epidemic last 3'ear, it is quite pi'obable that under favourable conditions, it may do even more damage this year, and every one should be prepared to combat it. Fortunately, it is comparatively easy to treat. If possible, all the dead wood and diseased leaves should be collected and burned during the dry season, and as soon as the trees begin to make their new growth after the rains begin, they should be thoroughly sprayed with Bordeaux mixture 4-4-50, to every gallon of which should be added a sticker, made as follows : — Resin ... ... ... ... ... 2 pounds. Washing soda (crystals) ... ... ... 1 pound. Water ... ... ... ... ... 1 gallon. Mix, and boil until the preparation is a clear brown, about one hour. This will make the Bordeaux spread and stick to the glossy surface of the lime leaves. After the first application has been made, the trees should be watched very carefully as time goes on, to see whether or not the new growth is becoming infected. If infections are found, it would be advisable to make another application of Bordeaux mixture. The number of applications necessary can only be judged according to the climatic conditions throughout the growing period. NOTES ADDED. The above article was written by Mr. Rorer before he left for Ecuador. The following notes are also of interest. In the Report of the Porto Rico Agricultural Experiment Station for 1917, pp. 29-30, reference is made to what is apparently the same disease : — " The wither-tip fungus {C olletotrichum gloaosporioides) has been quite active during the past year, partly because of lowered vitality in the trees from lack of fei'tilizer. A few cases have been noted in which the initial injury results from poor drainage, impervious subsoil, or use of sprays. The damage done by this fungus to vigorously growing trees is very slight." In the course of a visit paid on one day by Mr. Urich and myself to three lime estates in Trinidad, with very similar climatic conditions, (1.) The disease is for this reason also known as Blostom-'jlight. (Ed.) 1919.] THE WITHEB-TIP OF LIMES. 3 it was noticeable that the disease was much more marked in places where the cultivation was poor. Thus on one estate the older trees which have been in an abandoned condition for several years were badly affected, whilst close by young trees under good cultivation showed no sign at all of the disease. In order to guard against the introduction of the disease into lime producing islands in which it is not at present known, Proclamations have been issued in the Colonies of the Leeward and Windward Islands prohibiting the importation of all Citrus plants and parts of Citrus plants, including their fruits,|from all parts of the West Indies excepting those free of the disease e.'j. Antigua prohibits importations from British Guiana or any island or place in the West Indies except the islands of Dominica, Montserrat, St. Lucia and Grenada. W.G.F. 4 TBINIDAD AND TOBAGO BULLETIN. [XVIIL 1, FOO D CR OPS. EXPERIMENTS ON YAM CULTIVATION, St. Clair Experiment Station, 1918-19. By R. 0. Williams, Acting Supt., Royal Botanic Gardens and St. Clair Experiment Station. As reported in Bulletin XVII, 1918, p. 69 a planting distance experiment for yams has been carried out. Ten trenches each 200 feet long and 4 feet apart were dug 2 feet in breadth and about 18 inches in depth. These were filled partly with trash and partly with cow manure, then covered and banked up with soil in the usual way. The plants used weighed approximately \ lb. each and two of the trenches were planted at 1 foot apart, two at 15 inches, two at 18 inches^ two at 21 inches and two at 2 feet. The planting was done during the month of April, 1918 and the crop reaped during January, 1919. The labour was performed by a prison gang, but to enable one interested in cultivation of this kind to get an idea of the cost of labour, &c., and the profits to be derived from it, I will take the cost of cultivation in trenches four feet apart and of the same dimensions as worked out at St. Augustine under estate conditions in 1917-18. These were published in an article by the Superintendent of Field Experiments in Bulletin XVII, 1918, 66. It will be noticed that in this experiment the only difference in the cost of cultivation between wide and close planting is due to more plants being required and a little more labour iji planting, as all trenches are four feet apart and cost the same to prepare. The cost of cultivation and of yams used for planting if calculated on this basis would be for the ten trenches $44.51, and the value of the crop reaped at two cents per lb. $122.42, making a profit on the whole experiment of $77.91. As will be noted from the table given below, this experiment has shown that planting 15 inches apart in the rows has given the best return as whereas the 4 ft. by 2 ft. gave a profit of $9.93 per 1,600 square feet of land, 4 ft. by 1ft. 9 in. $10.05, 4 ft. by 1ft. 6 in. $16.61, 4 ft. by 1 ft. 3 in. gave $21.37 and 4 ft. by 1 ft. $19.95. ai m ^-3 k 4 C m to o o c O ultiv plant Planting distance. CO ge p 1 sue its. p- s "73 o * en 2 -^ s -2 . * 5 i? , 5J 1- c p4 - ii >=*^ P- 03 o c3 ^ -W o O +2 .4^ 12; ^ < H > o 125 LI). $ C. $ c. $ c. 4 ft. X 2 ft. ... 200 188 4 91b. 921 18.42 8.49 9.93 4 ft. x I ft. 9 in. 228 214 4-3 „ 934 18.68 8.63 10.05 4 ft. X 1ft. Gin. 2t;f) 232 5-5 „ 1,271 25.42 8.81 16.61 4 ft. x 1ft. 3 in. 320 301 50 „ 1,523 30.46 9.09 21.37 4 ft. X 1 ft. ... 400 363 4-0 ,, 1,472 29.44 9.49 19.95 6,121 122.42 44.51 77.91 1919 :\ EXPEBIMENTS ON YAM CULTIVATION. 5 To the small planter who wants to know what he can reasonably expect with good cultivation from an ordinary '• lot " 100 ft. by 50 ft. ; i.e. 5,000 sq. ft. planted at 4 ft. by 15 in. he could work out his estimate as follows : — Value of crop ... ... •• ••• $66.78 Cost of cultivation and plants ... ... 28.40 Profit ... ... ••• — 3Q-^^ ...4 ft. X 2 ft. ...4 ft. X 1 ft. 9 in, ...4 ft. X 1 ft. 6 in, ...4 ft. X 1 ft. 3 in ...4 ft. X 1 ft. To the larger planter who requires to reckon in acres, it may be added that, provided the conditions of soil &c. be the same over the whole area cultivated, the crop as calculated from that reaped at the distances under trial would be approximately : — 11*20 tons per acre on the 11-32 15-49 18'51 ;, ,J ... 17-89 These j'ields are very similar to those obtained at St. Augustine last year. The total crop reaped at St. Clair during last season from all kinds of Yams and under different methods of cultivation amounted to 17,332 lb. or an average of 4-4 lb. per yam reaped : 11,553 lb. of the crop was sold at 2 cents per lb. = $231.06, and 1,201 lb. at 3 cents = $36.03 ; total value $267.09. The balance, 4,578 lb., was reserved for planting. The cost of cultivation and reaping, including yams for plants, can be reckoned at about 3 to 4 cents per plant at 15 in. apart and as the average yield per plant was 4-4 lb., worth at 2 cents per lb., about 9 cents, there is a profit of 5 to 6 cents on each yam. EXPERIMENTS FOR 1919-20. An experiment has been laid out this year to test whether there is any advantage in selecting large yams for planting. A small area has been planted from : — (1.) 1 lb. plants cut from large tubers averaging 8 lb. each. (2.) Whole small tubers averaging i lb. each. (3.) Aerial tubers averaging 2^ oz. each. The varieties obtained from Barbados last year and varieties collected from other sources in the past are being tested on a larger scale than was possible before. 6 T BIN ID AD AND TOBAGO BULLETIN. [XVIIL 1. CACAO. NITROGEN CONTENTS OF CACAO SOILS PLANTED "WITH & WITHOUT BOIS IMMORTEL SHADE. By Joseph de Verteuil, F.I.C, F.C.S., Superintendent of Field Experiments. At a meeting of the Cacao Committee of the Board of Agriculture, held in December, 1917, Mr. W. C. Jardine asked that the nitrogen contents of the soil be determined, in the Full and No Shade plots of Field 5, River Estate, at the end of March, June, September, and December respectively. The object of these analyses is to ascertain whether there is a larger amount of nitrogen and nitrates in the soil where the cacao trees are shaded with bois immortel {Erythrina spp.) than where there is no immortel shade, and therefore whether the immortel trees are beneficial to the cacao trees in producing a larger supply of nitrogen in the soil. Samples of soil were accordingly taken during 1918 and analysed. These soils laiay be described as sandy loams, and their mechanical composition was very similar. The samples contained an average of 91 and 93 per cent, of fine soil and 9 and 7 per cent, of coarse sand for the Full and No Shade plots respectively. The composition of the air-dried fine soil for each quarter respectively: was as follows : — March, 1918. Moisture Volatile matter and combined water Mineral matter ... June, 1918. Moisture Volatile matter and combined water Mineral matter ... September, 1918. Moisture Volatile matter and combined water Minera 1 matter ... December, lOlS. Moisture Volatile matter and combined water Mineral matter... Full Shade. 0-84 3-62 . 95-54 No Shade. 1-12 4-82 94-06 100-00 100-00 0-84 3-48 .. 95-68 0-94 3-84 95-22 100-00 100-00 1-06 3-32 .. 95-62 1-06 3-52 95-42 100 00 100-00 0-92 4-28 .. 94-80 0-94 4-04 95-02 100-00 100-00 1919.] NITROGEN CONTENTS OF CACAO SOILS. The total nitrogen and nitrates were estimated on the air-dried fine soil and the results calculated on the fine soil dried at 100 deg. Centigrade. The figures obtained and the rainfall on the estate are given in the table below. Rainfall 191S. Cacao trees shaded with immortel. No immortel shade. Mar. —Total Nitrogen •Jan. -Feb. 5-49 •OSI 73 •101 7. Nitrogen as nitrates... March 1-31 •00093 7, ■00062 7, -] line —Total Nitrogen April-May 7-25 •07S 7, •096 y. Nitrogen as nitrates. . . .Tune 6-94 •00072 /, •0004S 7, Sept. —Total Nitrogen July- Aug. 26-71 •0S4 7, •091 7, Nitrogen as nitrates... September G-73 •00062 7, •00042 7, Deer. — Total Nitrogen Oct. -Nov. 13 •24 •129 7, •115 7, Nitrogen as nitrates. . . December 4-30 •00072 7, •00077 7, From the figures recorded above it will be seen that : — 1. The organic matter, total nitrogen and nitrates decrease during the .Tune and September quarters with the heavier rainfall and increase during the December quarter with the lowQr rainfall. 2. With the exception of the December sample, the total nitrogen is higher in the No Shade than in the Full Shade plot for each period respectively. But with regard to the nitrates it is just the reverse i.e. there are more nitrates present in the Full than in the No Shade plot. Owing however, to the fixation of nitrogen from the air by the bacteria in the nodules of the immortel roots and to the additional supply of nitrogen derived from the immortel flowers, leaves and pods bearing seed, the percentage of organic nitrogen in the soil is practically no less than in the No Shade plot. There is no evidence, however, that the larger amount of nitrates producad in the Full Shade plot is beneficial to the cacao trees as the average yield of the past two years for the Full and No Shade plots respectively, is practically the same as the average of the previous five years. Another question presents itself and it is this. Is the smaller amount of nitrates generated in the No Shade plot sufficient to produce a maximum crop ? As far as can be judged at present the amount of nitrates formed in the No Shade plot appears to be sufficient as the yield from the No Shade plot shows a smaller decrease (408 against 662 pods per acre) during the past two years than the Full Shade plot compared with the average yield of the first 5 years after the shade had been cut out. The smallest amount of nitrates found, -00042 per cent., was in the September sample for the No Shade plot and it represents what has 8 TEINIDAD AND TOBAGO BULLETIN. [XVIIL 1. not been utilised by the cacao plants or washed out of the soil by the rains. It is so to speak the reserve of nitrates in the soil. This amount although small in appearance represents 10^ lb. ot nitrate nitrogen per acre and as a good average cacao crop for the Colony viz. 4 bags per acre, removes from the soil in one year only 14 to 15 lb. of nitrogen, it would appear to be ample for the crop produced, since the formation of nitrates is continuous under favourable tropical conditions such as exist in the field in question. It must not be forgotten however, that a larger amount of nitrogen is required for the production of new wood, leaves and the husks of the cacao pods. This has been estimated by Marcano d) at 130 lb. per acre per annum. But as the trimmings, leaves and cacao husks are allowed to remain on the soil and decompose they are . sooner or later converted into nitrates for the plants' use. During this process of decomposition there is a small loss of nitrogen which may be estimated at 25 per cent, on 32 lb. per acre, and although there is at present no indication of a shortage of nitrates in the No Shade plot, this may occur later. But before this question can be definitely answered it will be necessary to carry out similar manurial experiments with different quantities of nitrogenous manures on Full and No Shade plots of known bearing capacity i.e. on which a record of the natural yield has been ascertained. (1.) Essais D' Agronomic Tropicale V, Marcano. 1919.] SUGAE. SUGAR CROP RETURNS 1919. The following Sections of the Produce Taxation Ordinance, No. 28 of 1918, specify the returns to be made of the sugar manufactured during 1919 :— Section 7. — (1.) On or before the loth day of January, 1920 the owner or manager of any sugar factory in Trinidad shall in respect of such factory make a return to the Receiver-General showing the amount of sugar manufactured in such factory during the 12 months ending on 31st day of December, 1919. (2.) For the purpose of testing the accuracy of any return made to the Receiver- General under this section or of obtaining information in case of failure to make a return any person authorised by the Receiver-General may enter any premises whether forming part of a factory or not and examine all books documents and papers referring to or in any way connected with the business of the factory for the purpose of testing the accuracy of the return or of obtaining information. (3.*) Any owner or manager of a sugar factory who — (a.) wilfully refuses or without lawful excuse neglects to make a return under this section, or (b.) wilfully makes or causes to be made any false return, or {c.) obstructs or impedes any person authorised as in this section mentioned in the exercise of any powers under this section, or (d.) refuses or neglects to produce any books, documents or papers as aforesaid or refuses to answer or wilfully gives a false answer to any question necessary for testing the accuracy of anv return or for obtaining information as to the amomit of sugar manufactured in such factory ; is liable to a penalty not exceeding £500 or to imprisonment with or -without hard labour for any period not exceeding six months or to both. Section 8.— (1.) On or before the 31st day of January, 1920 the owner or manager of every sugar factory in Trinidad shall pay to the Receiver-General the amount of the tax upon the sugar manufactured in such factory due under the provisions of this Ordinance up to and including the 31st day of December, 1919 but after making allowance for the sums paid under Section 4 of this Ordinance in respect of the shipment by him of any such sugar. (2.) If any sum due under the provisions of the preceding sub-section is not paid on or before the 31st day of January, 1920 such owner or manager as aforesaid shall forfeit the sum of £100 in addition to the tax payable as aforesaid. 10 TRINIDAD AND TOBAGO BULLETIN. [XVIIL 1. REPORT TO THE FROGHOjPPER COMMITTEE ON MR. GLASGOW'S SUPPOSED CURE FOR FROG- HOPPERS- By C. B. Williams, M.A., F.E.S. Entomologist in Charge of Frogliopper Investigations. At the end of October it was announced ia the local papers that Mr. Glasgow, dispenser at Orange Grove Estate, had discovered a cure for the frogliopper pest {Tomaqns saccharina). It was said to be a liquid which was poured around the roots of the cane thereby killing the nymphs, destroying the eggs, and also the fungus causing root disease and in addition hai'mful bacteria which the froghopper was believed to deposit. Mr. Glasgow was willing to give demonstrations of his method on any estate. During the next few weeks several planters visited Orange Grove to see his experiments there and two demonstrations were given on other estates, one at Caroni and the other at Cedar Hill. In view of the interest aroused and of the conflicting statements as to results I visited Orange Grove on November 6, in company with Mr. Moodie and Mr. Cox, and again alone on November 14 and 21. I also visited the treated fields at Caroni, in company with Mr. Glasgow himself on November 21, and the 'treated fields at Cedar Hill on November 20, with Mr. Fabian, and again on December 13. METHOD. The method consisted as reported, of the application of a liquid of secret composition, round the base of the cane plants. The liquid was said to cost about 6 cents per gallon local prices, and possibly 4 cents per gallon wholesale. Mr. Glasgow also said that as applied to the fields at Orange Grove by the rough and ready method of pouring on the ground from tobacco- tins, one gallon would treat about 20 stools, but that he expected by means of a spraying machine to be able to treat 30 or more stools with one gallon. With 1,750 stools per acre (the number at Orange Grove where all plants ai'e 5x5 feet) the amount of liquid required should be 50-100 gallons per acre, costing $3-ft6. As regards cost of labour Mr. Glasgow said that six boys could treat about four acres per day, and that on one occasion between 1.30 and 5 p.m. they did a plot of 2^ acres. The following other particulars were obtained from Mr. Glasgow (1) the liquid would keep in its diluted state for two years ; (2) it had no irritating effect on the skin '■= and gave off no poisonous fumes ; (3) 1-1 J oz. of the liquid as applied to the field would kill a man if taken internally. LABOKATORY EXPERIMENTS. On the 6th November we immersed two nymphs removed from their froth in the liquid as applied to the fields for about two minutes during which time they were prevented from crawling out. After this * Later Mr. Glasgow stated that the liquid has a slight irritating eflfect. 1919.] SUPPOSED CURE FOR FROGHOPPERS. 11 immersion they were both actively moving. Two hours afterwards, during which period they had been kept without food in a closed box, one was almost dead and the other sick. The test was repeated more thoroughly on November 21, when 25 nymphs were kept completely immersed for one minute and then removed and placed on grass roots. Two hours afterwards 8 were dead, and 17 alive. Of the 17 several were sick, but the majority were active and four had already made fresh coverings of froth. I tried to arrange for experiments in the power of killing eggs but, owing to a fear of his preparation being analysed, Mr. Glasgow would not allow me to take away trash containing eggs, which had been immersed in his preparation. FIELD EXPERIMENTS At Orange Grove. On November 6 Mr. Moodie, Mr. Cox and myself were shown fields 12, 13, 14 (Fig. I). The canes were second ratoons of B 6450. Field 14 had been treated twice with the liquid at the end of August; the eastern half of Field I'd had been treated once 12 T N TRACE ] ' « i_ n - 15 1 4 ■ ' Li n Fig-. I. at the same time ; the remainder of Field 13 and Field 12 had not been treated. It was said that at the time of treatment, Fields 13 and 14 were badly blighted. At the time of our visit the damage was slight but noticeable. There was, however, nothing to choose between 14 (treated twice) and the treated pact of 13 (treated once) or between the treated and untreated plots. Root disease was occasional on both treated and untreated areas. Further enquiry elicited the information that the fields had been limed in July and had received a dressing of sulphate of ammonia in September. Some, at least, of the claimed improvement must be credited to this treatment. On November 14 I visited Field 100 (Fig. II) in which one small section at the S.E. corner had received one application of the liquid. The canes were 1st ratoons of B 156. The northern half of the field had been given a dressing of sheep manure uniformly from one end to the other. 12 TBINIDAD AND TOBAGO BULLETIN. [XVIII. 1. D o < ir Tn Fig. II. "When examined the canes at the south-eastern corner A (treated) were distinctly better than those at the south-western corner B (untreated) and it was claimed that this was due to the application of the liquid. The change however was gradual and not distinct at the edge of the treatment. In addition the same difference was found along the northern edge of the field where there had been no difference in treatment ; the canes at the north-eastern corner D were very much better than at the north-western corner C. In fact the eastern end of the field, treated or untreated, was distinctly better than the western end. Further, on reference to my notes of last year, I find recorded on November 16, 1917, that a block of damaged fields just to the north of Field 100 (which was then in plant canes) were distinctly better at the eastern end than at the western end, without any difference of treatment. There is therefore little doubt that the superiority of the treated canes at A over those at B (which were untreated) is in part at least explain- able by differences, probably in soil conditions, without any effect on the part of the liquid. One or two other fields were visited at Orange Grove but in no other -case had any part of the fields been left untreated for comparison. Without this no reliable results can be obtained. Throughout the estate, on fields treated or untreated there were very few froghoppers. Caroni. A small block of canes at Caroni, field 77 had been treated on October 26. The canes were 1st ratoons of D 109. Mr. Glasgow brought 60 gallons of his mixture. This was said to be sufficient for half an acre, but " owing to there being no other land prepared " (the preparation consisted of the removal of the trash from 1919.'] SUPPOSED CURE FOB FROGHOPPEBS. 13 round the base of the stools) the whole was put on one small patch which I found to contain about 270 stools. This is therefore at the rate of 4|- stools per gallon — or about 550 gallons per acre with 2,500 stools per acre ; which at 6 cents per gallon would cost $33 per acre for material alone for one application. If one gallon of liquid to 20 or 30 stools is sufficient to reduce the number of froghoppers below the danger limit, an application at this phenomenal rate might be expected to exterminate them completel3\ On November 21 Mr. Glasgow and I examined the plots. There was no visible differences between the treated and untreated canes,, both of which was slightly but not badly blighted. We then examined the stools and counted the number of nj-mphs visible on the surface. On 120 treated stools at A we found 25 nymphs. On 120 treated stools at B we found 37 nymphs. On 120 untreated stools at C we found 45 nymphs. The application had reduced the number of nymphs from 45 to an average cf 31. i 1 1 I . 1 1 Fl£[cl 7 ! 1 1 (0 % c -^ 4 U (J "^ — u i. ■■^ +-• - u cT r - l-J o-> Tn :5 c \\ ^ "TRACE Fig. III. About 60 per cent, had survived the application. As many of the survivers were quite young there is no doubt that the application had not destx-oyed all the eggs. Eoot disease was not uncommon on both treated and untreated areas. It must be admitted that there were very few froghoppers even on the untreated portions and that, no doubt, if there had been more none would have been destroyed. But the value of the treatment depends largely on whether or not it is applicable before the numbers of the froghoppers have reached the danger limit. Cedar Hill. On November 1 a portion (exact limits not marked) of Field No. 106, 1st ratoons B 156, was treated by Mr. Glasgow "with his preparation (exact quantity not recorded). 14 T BIN ID AD AND TOBA GO B ULLE TIN. [X VII I. 1. I was not present at the application but on November 20 the treated cane from A to B (Fig. IV) appeared a little better than the untreated canes just to the north of A, but no difference could be seen between the treated canes be- tween B and C and the untreated canes to the east of this point. On December 11 f A' 1 1 m ,Fi,8ld '106 ■RO AD I visited the field again and counted the num- ber of nymphs visible on the surface of the ground in the treated and untreated areas. On 50 treated stools on the bed next to the trace along the western edge of the field I counted 102 nymphs, and on 50 untreated stools about 5 beds to the east I found only 32 nymphs. Fig. IV. So that there were actually more nymphs on the treated than on the untreated bed. It is naturally, not suggested that the treatment was responsible for this, but it shows that variation between different parts of a field must not be hastily credited to special treatments, and further that the mixture in question cannot be said to exterminate either the nymphs or the eggs. Eoot disease was present on both treated and untreated plots. COST OF APPLICATION, Leaving for a moment the question of the efficacy of the liquid in destroying the froghopper nymphs or eggs, I made, in collaboration with Mr. Borer, some experiments to get accurate information on the cost on application of such a method. Using knapsack sprayers, we found that it was impossible to moisten thoroughly the trash and ground at the base of the cane stools without using at least one gallon of liquid to every 12 stools, or 200 gallons per acre at 2,400 stools per acre. We further found that the cost of application by this method could not be brought much under ft2 per acre. So that the complete cost of one treatment of this type would be per acre at least ^2 in addition to the cost of 200 gallons of liquid. GENERAL CONCLUSIONS. If a liqu'.d C5ull be found that was thoroughly effective in destroying the froghopper nymph and eggs in one, cr, at the inost, two applica- tions, the method is not impossible, provided that the cost of the liquid 1919.] SUPPOSED CURE FOB FBOGHOPPEES. 15 itself is not prohibitive ; (4 cents per gallon should be the limit unless extermination is complete). In view of the general shortage of labour however, it is doubtful if the method would be applicable on a very large scale. The demonstrations so far given by Mr. Glasgow do not prove that his liquid is sufficiently effective in destroying either eggs or nymphs of the froghopper, or the fungi causing root disease. Possibly further demonstrations which he hopes to give next season at a more suitable time of the year may be more conclusive. December 16, 1918. la TBINIDAD AND TOBAGO BULLETIN. [XVIIL 1. COTTON. NOTES ON THE CULTIVATION OF COTTON. PEEPARATION OF THE SOIL. For the cultivation of cotton, a fairly light soil is preferable — soils known as "loams" or " sandy loams " are the most suitable. The land should be thoroughly cutlassed or weeded, lined and holes of approximately 18 inches square by 6 inches deep dug. The soil removed from the holes is mixed with 5 lb. (12 to 16 tons per acre) of well rotten pen manure and the holes refilled. When possible the land should either be ploughed or forked and harrowed before lining. PLANTING SEASON. There are two distinct periods in the life of the cotton plant : a vegetative period of some 4 to 5 months during which the plant makes its full growth and a reproductive period of some 3 to 4 months during which the bolls are ripening. During the first period a good rainfall is required to ensure a regular growth and the seed should therefore be planted in June or July at latest, at the commencement of the rainy season. The results of experiments carried out at St. Augustine with plantings in June, July, August and September showed a steady decrease in the crops for the later plantings respectively. Three seeds should be put to a hole and 4^ lb. of good seed will be sufficient to plant an acre and supply missing holes. In suitable weather the plants will begin to appear after 5 or 6 days and in order to obtain a regular stand the missing holes should be supplied by the end of the second week. DRAINING. If the land requires it, draining should be done immediately before or after planting so that the earth from the drains may be spread at the first weeding. It is a great mistake to believe that because a soil is of a fairly sandy nature it does not require draining. One of the chief causes of the dropping of the flower buds and shedding of bolls is the want of proper drainage. CULTIVATION. About four weeks after planting it will be necessary to make the first weeding. This should be done with great care, the grass or weeds close up to the plantlets being removed with the hand so as not to injure the young plants. Such injuries are liable to cause rotting of the stems. The plants should then be slightly moulded up. It is now time to do a preliminar3- thinning ovt bj' pulling out the weakest plant from each hole, care being taken to make the soil firm around the remaining plants. A second weeding will be necessary about 4 to 6 weeks after the first and the young plants should again be moulded up, and the thinning out completed. One and probably two other weedings will be necessary. The last weeding may be done as the bolls begin to open. 1919.\ NOTES OX THE CULTIVATION OF COTTON. 17 PESTS. The cleaner the cultivation is kept the freer it will be from insects pests. The most serious pest is the cotton stainer which makes its appearance shortly before the bolls begin to open. The best methods of control are trapping and collecting. This is done by tying a handfuU of seed-cotton on the plants at some distance apart ; the seed attract the stainers which settle in clusters on the traps when they can be shaken off into a tin of water containing a little kerosene oil. If the destruction is carried out systematically the pest can usually be easily kept in check unless very abundant. REAPING. Cotton should be picked when the boll is fully opened and its segments perfectly dry. No picking should be done while dew is on the plants or in rainy weather. If the cotton is picked too early the process of ripening is incomplete, the fibres are weak, they do not acquire the twist necessary to give them a good spinning quality and the cotton is difficult to dry. On the other hand cotton that is left too long in the open bolls loses strength, lustre and silkiness and may be so tangled up by the wind that it is difficult to gin. The pickers should be provided with a canvas bag 18 to 20 inches long and 18 inches wide, made to tie around the waist so that both hands may be free. The bag should have attached in front a pocket about half the size of the bag. Only the good clean cotton is put in the bag, any stained or soiled cotton is put in the pocket. In picking, care should be taken to prevent bits of leaf or any foreign matter from being included with the cotton. After picking the cotton should be dried by sunning in trays before it is put up for ginning. The Government Farm undertakes to gin and bale cotton and deliver same in Port-of- Spain at the rate of one cent per lb. of seed cotton. SEA ISLAND COTTON. Sea Island cotton is planted 3 feet by 2 feet or 4 feet by 2 feet, the cost of planting and reaping an acre may be estimated at S60 to $70 and an average yield of 300 to 400 lb. of seed cotton per acre may be expected. This cotton does not ratoon. THORNTONS HYBRID. This was a hybrid produced by Mr. T. Thornton in Tobago by crossing Sea Island with a " native " cotton. It was grown for some years in Tobago, &c. : but is not in cultivation now. The following figures are however of interest: — The cost of planting and reaping a three acre field of " Thornton's Hybrid" in 1913, at the St. Augustine Experiment Station was $68.27 per acre and the cost of cultivating the ratoons the following year was $44.10 per acre. This variety was planted 5 feet by 5 feet and the crops reaped were 755 and 485 lb. of seed cotton per acre respectively for the plants and ratoons. 18 TRINIDAD AND TOBAGO BULLETIN. [XVIII. 1. CAUTO COTTON. In 1916 an experimental plot was planted with seed received fi-om Jamaica. This is a tree cotton and is planted 7 feet by 7 feet. The j^ield obtained was 1,305 and 735 lb. of seed cotton per acre for the plant and first ratoons respectively. This plot is being carried on as second ratoons and is apparently quite good. Tlie actual cost of cultiva- tion and reaping was $112.40 per acre for the plants and $59.70 for the ratoons. This is high owing to the fact that the plot is barely one-fifth of an acre. The results have been sufficiently promising to warrant the trial of this cotton on a larger scale. SALE PRICES. The prices of cotton during war conditions have been high, and for the crops grown experimentally in Trinidad and sold in 1918, the following prices were received. Sea Island cotton 3s. 4d. per lb., Cauto cotton 2s. 3d. per lb. 1919.] 19 -HORTICTILTUEE. BEDDING PLANTS FOR TRINIDAD.d) By R. 0. Williams, Acting Supt., Royal Botanic Gardens, and St. Clair Experiment Station. This subject is a very wide one, and I know as individual members we hold different opinions as to whether certain plants should or should not be included in a list of plants suitable for bedding purposes in Trinidad. Some plants I shall mention would scarcely be termed bedders, but I have included them because bedding planis are somewhat few here, and those mentioned make good flower-garden subjects. There are manj' plants which under careful culture and suitable weather conditions can occasionally be grown. Amongst these should be included Double Daisies, Mignonette, Ageratum, Lobelia, Sunflower, Geraniums, Michaelmas Daisies, Hollyhocks and Gladiolus. AYhere masses of flowers in beds, &c., are i-equired it is no use to rely on these. I have therefore confined mj'self as far as pis.Hible to the best plants which are most suitable to our conditions. Annuals are a feature of summer bedding in English gardens, but the list of those which thrive here is a very limited one, attributable to several causes. Some of them of course will not thrive at all ; others .are not grov/n because of the great difficulty in raising them from seed, or because if raised from seed successfully, insect life is so abundant that many are destroj-ed. Although the growth of veg2bition is so rapid in the tropics, the laying out of a flower garden and the keeping a constant supply of plants in flower is not such an easy matter as it at first appeal's, as we have not the well marked seasons of Europe. If hero one relies on annuals for a constant supply of flowers, disappointment is sure to Le occasionally met for various reasons, such as weather, and lack of supply of good seed from abroad. "We h ive however the advantage of possess- ing many small shrubbj" fl.oweriug plants which can be utilized in the beds in such a manner that never at any time will the whole set of beds be entirely bare of flowers. I will deal With the plants under four headings: (1| Small shrubs, and perennial bedd(!rs. (2) BuUjous and Tuberous rooted plants. (B) Annuals. (4) Plants suitable for edging purposes. SMALL SHRUBS AND PERENNL\LS. The shrubby and perennial plants will ensure the garden being well stocked with flowers at all times ; they are al&o useful v.here quantities of cut flowers are required. Angelonla salicaruefolia is a lev/ shrub with erect spikes of violet coloured flowers. The white variety is also very pretty, and both can be used separately or in conibination with good effect. Althoui^h this (1.) A jiapftr read before a meeting of the Horticultural C'hib. 20 TBINIDJD AND TOBAGO BULLETIN. [XVI II. 1. plant is recorded as being a native, ib is not often seen growing wild in Trinidad. It can readily be raised by cuttings, and a large stock can quickly be obtained in this way from a few plants. Antirrhinums. — These plants, commonly known as Snapdragons, do moderately well in Trinidad during the dry season, but even then they cannot be fully relied upon being somewhat difficult to raise, and after planting out very subject to attacks of mole crickets. I have only been successful in getting one. really good bed, although I have made several attempts with good reliable seed. The method practised in England of raising good varieties by cuttings does not seem to answer, as a very small percentage of successes was obtained from several batches inserted. Begonias. — There are several handsome flowering Bcgonios well known here, such as B. coccinea , President Carnot, B. dominicalis, &c. and several with ornamental foliage. All will require a shady position if success is to be assured, as up to the present time only one {B. coccinea) has been proved to thrive well in full sunshine and through the dry season without constant watering. This is one of the best of Begonias, and a bed of it should certainly be in ever}' garden, either planted alone or mixed with other subjects such as Plumbago or Tube-rose. Begotiias are amongst the easiest of i^lants to propagate this being done by cuttings and seeds. The tuberous varieties, so largely used for bedding in England, I have raised from seed and got them to flower in pots, but as bedding plants they were complete failures. Clerodendron fallax. — One cf our best, larger growing, perennial bedders producing quite a wealth of scarlet flowers over a long period. It is only suitable for large beds or borders. Plants are easily raised from seed, and may be cut back several times after flowering when new shoots will develop and flower again profusely. Coleus. — These are most useful where beds of rich ornamental foliage are desired. They remain in perfection the whole of the wet season, but immediately become shabby at the first signs of drought. Coleus may either be planted as mixed beds or the richer coloured varieties kept distinct. Tn whichever way they be used, they make a good show. To get bushy plants the tips of the shoots must be pinched out when the plants are young. Young plants can be raised either by cuttings or seeds. Crossandra nndulirfolia.— S.n East Indian plant of from 1 to 3 feet in height. The growth is comparatively slow, and its rich reddish orange spikes of flowers remain in perfection a long time. It has handsome shining green foliage, and the plant is well suited for making neat compact beds of flower. There is another plant similar in every respect to this but with dull foliage. Crossandra may be propagated either by cuttings or by seeds. Crofons. — These can be used with el!"e:t where masses of colourei and variegated foliage are nee led. 1919.] BEDDING PLANTS FOB TRINIDAD. 21 CupJiea micropetala.— One of the best dwarf shrubs we possess for the flower garden, with small red and yellow flowers which are borne in great profusion. They are rather slow growing in the early stages, taking about two months from seed sowing till they are ready to plant out. When well established pinch out the top of each main shoot to allow them to make bushy growth. They will be in full flower at about five months from the time of planting out, and continue so for .about three months when they should be cut back and the beds lightly forked and manured : a second batch of flowers will then soon appear. Cuphea micropetala has a great attraction for humming-birds, and as many as half a dozen could be seen at times recently on plants occupying two beds in the Botanic Gardens. Old plants can be divided when necessary for propagation purposes, but it is best to raise young stock from seed- Dracaenas. — Good varieties of Draccenas are useful for planting in semi-shady places. In full sunshine the leaves are apt to burn. Propagated from pieces of stems cut into lengths of a few inches and inserted as cuttings. Galphimia glauca. — Shower of Gold. — A pretty shrub growing to a height of a few feet and commencing to flower when quite young. It is at its best in beds when from 1^ to 2 feet in height, being then covered with quantities of racemes of small yellow flowers. It is in flower for practically the whole year. Propagated by seed. Hibiscus. — H. rosa-sinensis has produced such a wealth of varieties at the hands of hybridists in Trinidad, and other parts of the world, that we have now about 150 varieties of many shades of colour, the majority of which have been raised in the colony, — largely by the Venerable Archdeacon Hombersley. Hibiscus plants make a very effective sight either massed in large beds or scattered in beds also used for other plants. A few Hibiscus, :such as the double varieties, pink and red, can also be grown as standards that is with one straight stem several feet high, and a head of foliage and flowers on the top. Ixoras.— Some of the smaller growing kinds may be used for large :beds, and if planted with a gi-ound work of balsams, tuberose, or verbenas, they look very pretty. They can be propagated by seeds or by cuttings. A certain amount of pruning will be required to keep them in neat compact bushes when usad in bods, this applies more especially to the yellow variety. This one does not come true from seed, and should be increased by division, or by root suckers. Ixoras are useful as hedge plants in moist districts. Lagerstroemia indica. — Crepe Flower.— There are several varieties, white, pink, red, &c. They grow to a good height and require occasional hard pruning after flowering when used in beds. They also make a good hedge in wet localities. Propagated by cuttings. Mirabilis Jalapa.—The Marvel of Peru, or Four o'clock, with its various colours of yellow, pink, white, &c., can be iTsed for bedding purposes if desired. 22 TRINIDAD AND TOBAGO BULLETIN. [XVIIL 1. Oleanders. — There are numerous varieties, white, pink, crimson, &c., •which are of great use as centre plants for large beds. They are somewhat difficult to propagate. Layering is a good method, also by cuttings. Pentas carnea a South African soft-wooded shrub grows to a height of 2 to 2^ feet, and makes a handsome flowering perennial for a mixed bed. It does not readily produce seed in Trinidad, but can be propagated by cuttings. For table decorations, (especially by artificial light, it is most attractive. Plumbago capejisis.-- One of the most useful plants for the garden, making a good show especially during the dry season. The only care necessary is occasionally to cat out the old shoots, close to the ground, keep the bad well forked and supplied with manure. Poinciana indcherrima, — Barbados Pride. — There are two varieties yellow and red ; both are well known. They flower at the tip of each shoot which should be cut back after flowering if the plants are intended to be kept small. Propagated h\ seed. Poinsettia. — There are three varieties in Trinidad, viz.: the " double" red, the ordinary red and the so-called " white " which is really a pale- yellow. The former makes the best show and carries its coloured bracts for a much longer period. Plants of the white can be grown with it to good efiect. All are propagated by cuttings, but the double does not root as readily as the other varieties. The white does not come true from seed. Boses. — Speaking geuerallj* hybrid Teas and Teas succeed best although just a few hybrid Perpctuals notably Paul Neyron and Snow Queen do well, A few roses which can usually be relied iipon to make a good show in Trinidad gardens are Helen Gould, Etoile de France, Johnkeer J. L. Mock, Etoile de Lyon, Lady Hillingdon, Mdme. Constant Soupert, Radiance, Helen Good, the Maman Cochets, President Taft, La Tosca and Marechal Neil. Biissclia juncea. — Antigua heath is a good standby, as it is practically always in flower. It is a prettj' sight to watch how this plant attracts humming-birds, some being nearly alwaj's seen working at the flowers. Russelia makes a pretty combination if planted with the variegated Pedilanthes. Both thrive in dry situations. Propagated by cuttings or division. Salvias. — The best known here is probably Salvia splendens which makes a xery gay show when grown where it gets a little protection from sun. It can readily be propagated by cuttings or slips, a few inches long, inserted in sandy soil. Salvia coccinea the Scarlet Sage grows about two feet high, and produces quantities of flowers which usually drop off by afternoon leaving the plants bare. "Where however one wants morning flowered plants this one is very acceptable. Of much more use for bedding purposes is its" white vai'iety, S. coccinea var. alba, which has- not the disadvantage of dropping its flowers in the early part of the 1919.] BEDDING PLANTS FOR TRINIDAD. 23 day. They form pretty, v/ell shaped plants, and make quite a show at two months from seed, continuing up to 5 or 6 months old, when they maj^ be cut back, the beds well manured and the plants allowed to shoot again, producing at this second flowering just as good a show of flowers. Once established in the garden, self sown seedlings will be found abundantly. Scutellaria coccinea.—Thh plant is one of the best scarlet perennials for general purposes. It grows from a foot to eighteen inches in height and is nearly al\vay3 in flower. "When it begins to get shabby it can be cut hard back, the bed dug and manured, and in a short time is again in full flower. In this way it will occupy a bed for a very long time. Thunhercjia erecia.— There are two varieties, blue and white. They form neat shrubs a few feet in height which flower abundantly. Propagated by cuttings or seeds. Turnera.—A. low growing, bushy shrub, producing an abundance of sulphur coloured flowers violet at the base about 2 in. in diameter. Leaves small about 2 in. by 1 in. and indented. It makes a good display during the morning, the flowers closing before noon. It is readily propagated by division, suckers or seeds. Vincas— Old Maids or Periwinkles, often serve a useful purpose as edgings or ground work to beds or borders. The white variety can be seen at the Red House Grounds, helping to hide the formal concrete edges to the x'oads. Vincas are natives of the West Indies, and for this reason many people are apt to look down upon them and not give them the position in the garden they deserve. They are most useful, hardy plants, rank in point of beauty with many of the more tender exotics, and flower throughout the whole year. There are three varieties the pink, the white, and the white with a red centre. Propagated either by cuttings or seeds. At Kew the Vincas were found very difficult to propagate and most success was obtained from cuttings in pure sand. They were used there annually as a border to the porch of the water lily house with good eflect. BULBOUS AND TUBEKOUS ROOTED PLANTS. Caladiums are good for planting in beds or garden vases during the wet season. In the dry season they should be taken up and placed in pots. Good tubers of bright coloured varieties should be imported. Cannas are amongst the best flowering plants, as if properly treated an almost unbroken supply of flowers can be obtained from the same beds for several years. Cut down the old flower stems quite close to the ground immediately after the flowers drop as there are plenty of young shoota coming to take their place. Cannas are gross feeders and will take liberal supplies of manure with advantage. They may be propagated either by seed or by 24 TRINIDAD AND TOBAGO BULLETIN. [XVIII. I. division, but the latter method is recommended where plants of the same variety are required. The separate colours such as red, yellow, or pink, massed in beds look very pretty and with attention to the heights of different varieties excellent effects can be obtained with mixed beds. Occasionally during very wet weather the leaves are attacked with a fungus which somewhat detracts from the appearance of the plants. This can be remedied by spraying with Bordeaux mixture, and keeping the shoots thinned so that air and light can get amongst them. Dahlias are now coming much into prominence and appear to thrive well under Trinidad conditions. The best strains are of course from imported tubers, although good varieties can also be raised from seed. I have had good singles flowering recently at six weeks from seed. They deteriorate in this climate after being under cultiration a short time. Tuberose. — This is a Mexican plant and quite one of our best bulbous plants for bedding out. The single variety is most commonly seen, although a few people have plants of the double. It is most useful in beds which are also planted with permanent shrubby plants such as Ixoi'as, Hibiscus, Begonia coccinea, &c. The spikes of pure white flowers grow from two to three feet high and are very sweetly scented. Zephyranthes, are small native bulbous plants of several colours, white, pink, or yellow. They are very abundant, and the pink and white can be used as edgings for beds. Their only drawback is that they only flower for a few days at a time, and the foliage looks some- what shabby when they are drying down, or when as is frequently the case they become attacked by caterpillars. Whilst in flower however a prettier plant could not be desired. The j^ellow although it thrives in drains, sides of roads, &c., is very difficult to establish in a garden bed. ANNUALS. The list of annuals one can grow with success here is not a long one. I have however dealt with those which from experience have proved to thrive well. Amaranthus. — A.caiidnttis is the well known Love-lies-bleeding with drooping spikes of reddish purple flowers. The plant grows 2 to 3 feet high and makes a good show in the flower garden. It is especially suited for large beds. There are several other species of Amaranthus which are fine ornamental foliage plants, the heads being of a variety of colours Ai'^^ crimson, green, purple, orange, bronze, yellow, and various shades of ''^■' red. The flowers in these species are inconspicuous, but the foliage makes up for this. A bed in the Botanic Gardens last year could be seen as a bright spot of colour from the opposite side of the Savannah. Good plants of Amaranthuses can be grown from locally raised seed. Mole crickets are troublesome to the young plants. 1919.] BEDDING PLANTS FOR TRINIDAD. . 25 Asters. — With care and attention Asters will grow well although they do not produce such fine flowers as in English gardens, neither can they be relied upon to make the same massed effect. Propagated by seed. Balsams. — Our garden balsams are botanically known as Impatiens, so named because the seed pcds when nearly ripe are impatient of the slightest touch, the valve discharging the seeds at the least provocation. There are several florists strains hut the Camellia flowered balsams are the finest and thrive well. Seeds can be bought in several distinct colours, such as white, cream, rose, salmon-pink, scarlet and violet, and if they be kept apart from each other and seeds selected from the best double flowers, good balsams can be produced for several genera- tions from home grown seed. I have had good double flowers true to type from the fourth generation of seeds grown here from white. The advantages of balsams are that they make a good show, can be raised and brought into flower quickly; they thus serve a very useful purpose if there is likely to be a bare time in the flower garden. The seeds are easily raised being simply sown in drills out-doors in a sunny place and transferred to the flower beds when a few inches high. Browallia speciosa major is one of our introductions of last year. Its close relation, Browallia demissa, is a common native plant. They are somewhat ditficult to raise from seed being very slow in growth but fully compensate one later by the lovely show of blue flowers they are capable of producing. It grows to a height of 18 inches to 2 feet and produces seeds in quantity. The period of growth from sowing of seed to the time it must be discarded from the flower beds is about seven months. Cockscombs do best in the dry season, as during heavy rains they tend to make very vigorous growth at the expense of good heads of flower. Cockscombs very readily reproduce themselves here by seeds. CosTOos.— The yellow or orange cosmos is best suited for dry weather conditions, as although making smaller plants during that time they produce more flowers than they do when grown in wet weather. It reproduces itself naturally and can become a regular weed in the garden. The pink and white varieties are much mors delicate. -Coreopsis.— These are first rate bedding plants, and make useful flowers for house decorations. They are natives chiefly of the Northern and Central parts of America. Two species, C. Drummondii and C. tinctoria, with their numerous colour variations have given us luost of the varieties of annual coreopsis used in gardens. C. tinctoria grows frcm two to three feet high and produces bright brown and yellow flowers. Seedsmen have produced a variety of strains -of different colours from this and also a dwarf one. 26 TRINIDAD AND TOBAGO BULLETIN. [XVIIL 1. C. Drummondii grows from 12 to IS inches high. The flowers are yellow \Tith a ring of crimson around the di-:c. This is the most valuable plant and the most attractive for flower beds in Trinidad. It readily reproduces itself by seed, in fact quantities of seedlings can usually be seen growing around the old plants. Another species C. grandiflora also does well with us here and remains in bloom for a long time. Cupliea miniata is an introduction of 1916 and has proved valuable as a bedder, occupying a bed for nearly eight months during part of the dry and wet season. This is a long period for an annual in Trinidad. It is cjuite a dwarf plant scarcely reaching a foot in height with scarlet flowers. It readily reproduces itself by seed so there is no fear of losing it. Dianthus. — A. prett.y group of garden flowers closely allied to the carnation. They grow from about six inches to one foot in height and have a wide range of colours from white through various shades and markings to blood-red. Great care must be taken in raising the young seedlings. Sow the seeds in boxes of very flue soil and prick off as soon as large enough, later transplant to their permanent position. As an edging to a bed they are very effective, or for small ribbon bads or bordeis. Gaillardias make nice compact plants which produce very freely large daisy like flowers of numerous colours, red, yellow, orange, &c. They reproduce themselves readily from seed and unlike many other annuals do not deteriorate when seeded in this country. Seedlings grown up to the fourth generation have been noticed to improve rather than the reverse. Gomflirena gloho?a. — Bachelor Buttons are very common but are of great use especially in the wet season for filling vacant beds. They also do well in the dry season. The white and purple varieties are the best to cultivate and thej' occupy the beds tor from three to four months. Marigolds. — Both African and French Marigolds are good showy plants when grown in the right season. The dry season is the best for the purpose especially for the French variety as during excessive wet weather they tend to make much foliage at the expense of the flower. The African varieties are more suited for the wet season and we have recently had a fine bed of Orange Beauty in the Botanic Gardens. These occupied the beds for four months. Marigolds are amongst the easiest plants to raise from seed and will be of no difficulty to rear provided sturdy plants be obtained bj' growing in sunshine. They seed here readily. Na&tuvtlmns. — I cannot strongly recommend Nasturtiums as a good bedder under Trinidad conditions, but occasionally with care one can get a good bed of the Tom Thumb variety, and they are then well worth the trouble bestowed on them. The seeds produced are very few compared with what one obtains in England. 1919.] BEDDING PLANTS FOE TRINIDAD. 27 Petunias. — These showy annuals have been derived from P. nycta- giniflora an annual, and P. violacea a perennial. That they may bs grown here with success is amply proved by exhibits at the Club's shows, but they require more care than many of the other annuals mentioned. They are best raised from seed, but can also be raised by cuttings. Mole crickets are very troublesome to the young seedlings in the beds. There are many varieties of Petunias, double, single, fringed, &c., but for bedding purposes here the single appears to give the best results. Phlox Driunmondii.— This pretty bedder is a generiil favourite and an easily grown plant. There are varieties of a wide range of form and colour, all derived from the red-flowered type found in Texas. They are easily grown from seed and once thsy become established self sown seedlings will always be found in close proximity to the old plants. Phlox are most suitable for small beds or planted between roses where they help to brighten the beds. Many rose growers m England make a regular practice of planting Phlox Drummondii in the beds as they ttike little from the soil and lend a bright splash of colour as a ground-work to the roses. Tithonia sjieciosa.—X pretty plant growing to a height of several feet with lovely orange coloured heads of composite flowers. It thrives well in Trinidad, reproduces itself readily by seed, and is very suitable for large round beds. Torenia asiatica, locally known as Pansies, can be utilised for small beds dming the wet season. Seedlings as a rule are very plentiful as the plant appears to have become naturalised. Verbenas.— Bedding Verbenas of hybrid origin are always favourites, owmg to the great variety of colours and the easiness with which they can be cultivated. For 'fancy shaped beds, or as a groundwork to shrubby plants, they are most suitable. Good varieties can be raised from seed, and afterwards propagated by cuttings or layers, as each httle shoot where it touches the ground forms roots and can afterwards be severed to form a new plant. When Verbenas become too massed in the beds, they quickly damp off in rainy weather. It is best to renew the beds with young plants or cuttings before thay reach this stage. Verbenas make the best show during the dry season if well watered. Zinnias can be reckoned among the best if not the ve:y best annuals for general purposes in Trinidad. They give a brilliant show of colour, are easily raised, flower quickly and very rarely fail. They take two or three weeks from the time of sowing the seeds to the time of transplanting in the beds, are in full flower in from six weeks to two months and over by four months. If double zinnias are required it is best to raise them from introduced seeds which have been especially selected by the nurseryman. If one takes any chance seedUngs which come up in the beds the majority will usually be singles of inferior value. Zinnias are usually grown as mixed colours, as the shades associate so well in a bed that it is not necessary to keep the colours separate unless there is a colour scheme in view. It is a change 28 TBINIDAD AND TOBAGO BULLETIN. [XVIIL 1. however to see occasionally beds of one colour, such as primrose yellow or the red known as Fireball. I tried the white recently but it was far from being a success as the colour was not pure enough. The garden race of Zinnias have all come from Zinnia elegans a Mexican plant. PLANTS SUITABLE FOR EDGING PURPOSES. Alternanthera. — A good edging plant is the well known Alternanthera which can be clipped to form a neat compact border a few inches in height. Alyssum. — This pretty border plant can be easily raised but grows best during the dry season. Coleus (Climbing variety). — A small Coleus of many colours on a ground work of green, and of scandent habit is very abundant in gardens here. It can be trimmed to form a neat border to a bed. Myosotis or Forget-me-nots. — A very old favourite in the flower garden, but very useful especially during the wet season, for covering bare patches of soil amongst stronger growing plaiits. Planted in small beds or as edgings, it is very pretty and can be dug up and replanted when it begins to look shabby. It soon dries up in the dry season unless very well watered. Violets make a vei-y neat edging to beds especially in the wet season and should also be grown for gathering for the house. The leaf growth is so vigorous that the tiowers are usually hidden. Propagated by division. GENERAL. As a last word I should like to mention that the reason why so many annuals fail here is the difficulty of getting them past the seedling stage. My principal suggestion here and one that I have found to answer well with most seeds is to sow them in boxes and cover till they begin to germinate when they must be immediately transferred to a sunny position, care being taken that they are never allowed to get dry. Seedlings grown in shade become weakly and drawn, and quickly succumb when planted in the open ground. The plants mentioned in this paper are all suitable for planting throughout the year except those given below which are most suitable for either the dry season (January to May) or the wet season (.Tune to December) respectively. Plants for the dry season. — Antirrhinums, Amaranthus, Cockscomb, Cosmos, Dianthus, Marigolds, Nasturtiums, Petunias, Phlox Drum- mondii, Verbenas, Alyssum. Plants for the tvet season. — Coleus, Mirabilis Jalapa, Salvia splendens Browallia speciosa major, Torenias, Forget-me-nots. Rose Leaf Spots RosK Mildew 1919. \ 29. THE FUNaOUS DISH.iSB3 OF R03E3 AND THEIR TREATMENT. By James Birch Roree, Mycologist, Board of Agriculture. With One Plate. On account of the increased interest in rose growing which has- been fostered by the Horticultural Club during the past four or five years, many enquiries have been received by the writer in regard to the treatment of rose diseases. As a result, numerous specimens have been examined in order to ascertain the causes of the diseases, and a series of experiments carried out to find some practical and easy method of combating them. Though there are several destructive diseases and insect pests of roses in the colony, it must always be remembered that rose plants are very susceptible to unfavourable soil and climatic conditions and their sickly appearance is not always due to diseases or pests. These plants are rather particular as to soil requirements ; good drainage and abundant manure being necessary for successful results. It is fatal, however, to manure rose plants heavily if the ground is not thoroughly drained, as this induces root rots of various kinds. It is essential also that rose gardens be kept free from the roots of other plants, which seem to have a very harmful effect on rose bushes. There are three fungous diseases of roses which occur wherever these plants are grown, in addition to which there occurs in Trinidad two diseases which have not been reported from other countries so far as the writer knows. All these diseases do a great deal of damage to rose gardens every year, and the black spot, leaf spot and mildew are so common that healthy plants cannot be grown unless some means are taken to combat these troubles. BLACK SPOT DISEASE. Perhaps the commonest of all the fungous diseases of roses is the so-called " Black Spot " caused by the fungus Diplocarpon rosce, Wolf, {Actinonema roses). This disease is characterised by more or less irregularly circular, or oval brown, black spots upon the upper surface of the mature or nearly mature leaves. The spots are quite small at first, but rapidly increase in size during damp weather, several often coalescing, so that one-third or one-half of the leaf surface may be affected. As the spots grow older they become grey in the centre^ while the adjacent parts of the leaf turn yellow. See upper figure of plate. The leaves, even those which are but slightly afiected, fall from the plant prematurely, so that sometimes the ground beneath the bushes i» covered with fallen leaves. Naturally, the plant immediately puts out new leaves, which under favourable weather conditions, become infected in turn and fall to the ground ; thus the bushes become greatly- weakened and begin to die back from the tip. ,30 T BIN ID AD AND TOBAGO BULLETIN. [XVIII. 1. LEAF SPOT. Another disease, somewhat similar to the Black Spot, is that called "Leaf. Spot" caused by the fungus Ccrcosj^ora rosccicola, Pass. This disease, in appearance, is somewhat like the Black Spot, but can be readily distinguished from it because the spots are circular, and have a distinct dark purplish border. The effect of both diseases on the plants is the same, namely, premature and repeated defoliation which gradually weaken the bushes. POWDERY MILDEW. This disease is very common at certain seasons of the year and is very destructive to certain varieties. The fungus causing the disease is known as Splucrotlteca 2^<^'>'osa, Lev. The fungus attacks the verj' young leaves and shoots and covers them with a fine flour-like mildew. The affected leaves and shoots become dwarfed, curled and deformed, and soon wither up and die. See lower figure of plate. This disease spreads very rapidly, especially during the time of the year when the nights are cool. Picpeated attacks of the disease cause the plants to lose their vitality. Treatment. All three of the diseases mentioned above yield readily to the same treatment. Experiments liave been carried out in which various fungicides have been used, and though several have given good results, the most successful have come from the use of flowers of sulphur mixed with dry arsenate of lead. This is much easier to apply than liquid fungicides, as it is simply dusted on the plants, and does not discolour the folitige and flowers to the same extent. The flowers of sulphiir should be very iine. so that it will pass through a 200 mesh to the inch sieve, and dry arsenate of lead tshould be added at the rate of one pound to every nine of sulphur, and thoroughly mixed in. (D It is necessary to make several applica- tions of this mixture to the plants, especially at the beginning of the rainy season, before the plants become badly infected. It must alway be borne in mind that plant diseases really cannot be cured but only prevented. The numbers of dustings necessary for a season cannot be definitely laid down, but is dependent altogether on weather conditions. At the beginning of the season however, it is advisable to make three or four applications at intervals of from seven to ten days. Later in the season the interval between the dustings can be lengthened according to judgment. Daring the past season, several experiments have been carried out ^\ith the sulphur arsenate mixture, as a control for the leaf spots and mildew, and at the time of writing the treated plants are practi- cally free from fungous diseases, and in very healthy condition, while the untreated plants are badly affected, or even leafless. (1.) Sulphur and arsenate of lead can be inuxhased locally, hut the i^rices are very high, which makes the treatment rather costly. The IJoard of Agriculture has, however, ordered a mixtitre made 1)3- the Union Snliihur Conijiaiiy, which will be sold at a reasonable rate. I'he Board "also lias on hand a limittd number of J'uut ■r»«a/acie" below a three- fifths standard. In making the awards the judges have aimed throughout at gauging as accurately as possible the amount of effort and industry correctly applied by each competitor to his work. We have not been unduly influenced, therefore, by the " crop" appearance which largely depends on natural soil-condition not to be appreciably modified in the space of six months. (1) For the rules of the Competition and the boundaries of the disttict Sec Bulletin XVII 1918 page 49 (Ed.). 1019.] CANE FAEMEES' PEIZE COMPETITION. 35 ^Yith respect to the system of " marking " it was found expedient to amplify tlie outline given in Rule 6 and divide the 80 marks allowed for " Tillage " into " Tillage Proper " 60 marks and " Cultivation or Up Keep " 20 marks. It was also thought just and advisable, bearing in mind the aims of these Competitions, to allow under the head of "General" a small number of marks, viz: 4, for theoretical knowledge v.'ithout a due proportion of which no industry can ever be progressive. As the results showed that over 80 per cent, of the competitors had some grounding in this subject and 75 per cent, of these had put their knowledge into practice also, the indications of the possibility of a future healthy Cane farming industry are indeed hopeful. We unhesitatingly pronounce the Competition as a whole a success. The competitors have generally proved themselves intelligent and persevering workers, actuated by a healthy spirit of rivalry and we regret only that there are not more prizes within our power to recommend. When the individual results of the two districts are compared it will be noticed that competitors in the No. 2 district have been keener than in the other. In that District only 9 marks separate the 83 of the 6th place from 92 of the first, while even the 21st on the list was but 32 marks below the prize winner. The champion of the whole Competition, however, is in the No. 1 District. Special mention must be made of the following: — Samuel Taylor (98 marks) who has won the first place in No. 1 District and secured the highest number of marks in the combined results may be termed a model Cane-farmer. He is an active member of the Savana Grande District Agricultural Society and possessed of some " book-learning." Yet, with his own hands he has done most of the work of his farm and reared a fine-looking crop of canes on a stiff slope that was quite recently under para grass and " black-sage " and bore a bad reputation. Hosein Baksh (82 marks) the winner of second place in No. 1 District also deserves praise for hia courageous effort with a piece of land very similar to Taylor's. Having no book-learning and little practical experience this competitor had relied solely on the instruction of the Adviser and deserves approbation for his creditable attempt, in spite of sceptical neighbours and compatriots, to carry out those instructions. Jama (81 marks) also deserves praise particularly when her sex is taken into consideration. Simon Fortune (92 marks) the winner of the first place in No. 2 District had the advantage of better soil and situation than the foregoing but fully deserves his success. His cane garden is evidently kept as a " garden " indeed. The names of a few otliers that have earned distinction for marked superiority in some branch or other of the work appear in the complete list of " Distinctions " below 36 TBINIDAD AND TOBAGO BULLETIN. [XVIIL 1. In exercise of the privilege granted under Rule 8 the judges beg to suggest that the prizes be awarded as follows : To the Northern or No. 1 District a first prize of Mty dollars as advertised ; second prize twenty-eight dollars instead of thirty-five, and thii'd prize seventeen dollars instead of twenty. As there is a tie for the fourth place we suggest that the ten dollars offered as fourth prize be equally divided between the two competitors. To the Southern or No. 2 District — a first prize of fifty dollars as advertised ; also the second prize of thirtj'-five dollars ; and as four competitors are grouped together for the third place we suggest that the remaining forty dollars of the prize money be shared equally by them. These suggestions have been embodied in the table of results. In conclusion we beg to state that we have executed our commission methodically and given careful thought to our suggestions and remarks. and hope they meet with your Excellency's and the Board's approval. We have, etc. December 30, 1918. (Sgd.) E. S. SWAN. C. M. ROACH. LIST OF DISTINCTIONS. Names. Number of Disti'ict Samuel Taylor Simon Fortune Katiwarroo Jama ... Paul Gobin I. Bridgelalsingh 1 2 1 1 1 1 Tillage percentage of marks. Cultivation percentage of marks. Theory, Etc. percentage of marks. 100 per cent, 95 95 95 95 95 per cent.. 95 „ 95 per cent. 95 per cent. 1919.] CANE FARMERS- PRIZE COMPETITION. 37 LIST OF PRIZE WINNERS. No. 1 District. 0) o 5 Name of Competitor. Locality. Prize. Marks. Amount. 1 Samuel Taylor Garth 1st 98 ftSO 2 Hosein Baksh Gasparillo 2nd 82 28 3 Jama ,, ... 3rd 81 17 4 Ramsehai Craignish 4th 80 5 5 •T. Dookie Gasparillo 5th 80 5 No. 2 District. 1 [Simon Fortune Princes Town ... 1st 92 $50 2 N. Farrell Lothian s 2nd 87 35 3 Katwarroo Palmiste 3rd 83 10 4 Paul Gobin Bronte 4th 83 10 5 Edward Phillips Lothians 5th 83 10 6 Henry Benjamin Malgretoute ... 6th 83 10 CANE FARMERS P RIZE COMPE TITIC )N 191 9. The Board of Agriculture has instituted a competition this year in the Tacarigua-Caroni and Couva-Chaguanas Districts, under the charge of Agricultural Adviser, Mr. C. McD. Roach. The rules are the same as those for the 1918 Competition (Bulletin, Department of Agriculture, XVII. 1918, 49). The Competition will be confined to two Districts. No. 1. — Tacarigua-Caroni bounded as follows : — North— Line 2 miles north of and parallel to Eastern Main Road. South— Chaguanas-Caparo Road. East —Line crossing Chin-Chin Road by 2 mile post Mausica and Lopinot Roads. ^Vest — Maracas, Curepe and Caroni Savannah Roads. j;[o. 2. — Couva-Chaguanas bounded as follows : — North — (3haguanas-Caparo Road. South— Hermitage Road. East — Line from Hermitage-Caratal junction to Long- denville crossing Couva Main by 5 miles. West— The Sea. The following Prizes will be given in each District : — 1st 2nd 3rd 4th Prizes. District (1) Tacarigua-Caroni ...•?50 $35 S20 $10 (2) Couva-Chaguanas ...$50 $35 $20 $10 38 TBINIDAD AND TOBAGO BULLETIN. [XVIIL 1. TRINIDAD CA.CAO PRIZE COMPETITION, 1919 20. Poole and Rio Claro Districts. 3rd 4th oth Gth 7th $40 130 §20 *15 $10 $:^u $20 $15 $10 $ 5 The Board offers prizes to the value of 440 dollars for the encourage- ment of good cultivation of Cacao by Peasant Proprietors and Contractors. RULES. (1.) Prizes will be awarded for good cultivation of cacao. (2. ) Prizes will be awarded in two classes. Class I. — For Peasant Proprietors with not more than 16 acres in cacao cultivation in one piece. Class II.- For Contractors. (3.) No Peasant Proprietor will be allowed to compete in Class I who has less than S acres of bearing cacao, no Contractor will be allowed to compete in Class II who has less than 2h acres in trees 3 years old at the timu of entry. (4.) No person can compete in more than one class. (5.) Prizes may not be given unle.ss there are at least oO Competitors in each of the classes. (G. ) The prizes offered arD as follows: — M 2nd Class I. — Peasant Proprietors $80 $60 Class II.— Contractors ....$60 $45 (7.) The Competition will be confined to the I'oole and Rio Claro District, bounded as follows : — North by a line drawn across the Cunapo youtliern Road at the IGth' mile. South by the Ortoire River. East by a line across the Naparinia-Mayaro Road at the 32nd mile. West by the Poole River. (8.) The Competition will be for the period May 1, 1919 to March 31, 1920. Due notice Mill be given before the judging commences. (9.) In judging marks will bo given under (he following heads : — (1.) (General Cultivation and Tillage ... ... 50 points. (2.) Sanitation and Treatment of Disease ,. ... 30 ,, (3.) General, including Cro}! Records, live stock and any special features ... ... ... ... 20 ,, (10.) The Board of Agriculture, on the recommendaticjn of the judges, may withhold or alter the value of any or of all the prizes if cultivations entered for competition are not considered of sufficient merit. (11.) Applications for rules and entry forms should be made to the Agricultural Adviser, at Rio Claro or at the ofiice of the Dep.irtmeiit of Agriculture, Experiment Station, St. Clair, ]\nt-of Sp.iin. Entry to Competition Free. Entries may be sent post free if addressed to : — The Agricultural Adviser, Rio Claro, or The Director of Agriculture, Experiment Station, St. Clair, Port of-Spain. Mr. L. Mota, tlie Board's Adviser will visit all holdings entered for competition and give advice as to the best methods of cultivation, free of charge. 1919.'] 39 TOBAGO CACAO AND VEGETABLE PRIZE COMPETITIONS, 1919-20. The Board offers prizes to the value of $248.00 for the encourage- ment of good cultivation of Cacao and Vegetables by Peasant Proprietors and Contractors. Cacao Prize Competition- RULES. (1.) Prizes will be awarded for good cultivation of Cacao. (2.) Prizes will be awarded in three classes: — CI-.ASS I. — For Prize Winners in 1917. 1st Prize ... ... ... ... •$ 25.00 2nd Prize ... ... ... ... 15.00 Class II. — For Peasant Proprietors who did not win a prize in 1917. 1st Prize .. ... .. ... $ 25.00 2nd Prize ... ... ... ... 20.00 3rd Prize ... ... ... .., 15.00 4th Prize .. ... ... ... 10.00 5th Prize ... ... ... ... 5.00 Class III — For Contractors. Isb Prize ... ... ... ... $ 20.00 2nd Prize ... ... ^ ... 15.00 3rd Prize ... ... ... ... 10.00 4th Prize ... ... ... ... 5.C0 5th Prize ... ... ... ,. 3.00 <3.) No person can compete in more than one class. (4.) Previous prize winners can only compete in Class 1. (5.) No prizes will be awarded in Class 1, unless three-fourths of the 1917 prize winners compete. (6.) No Peasant Proprietor will be allowed to compete in Class IT unless he or she has not less thin 3 acres of land of which 2 acres must be in bearing Cacao. (7.) No prize will be awarded in Class II unless there are 50 entries. (S.) No prizes will be awarded in Class III unless there are at least 25 entries. (9. ) No Contractor will be allowed to compete, whose contract is less than three acres, with less than 1 acre in bearing cacao. (10.) Tlie Competition will be for the period April, 1919 to May, 1920. (11.) Marks will be given under the following heads : — Cultivation ... ... ... ... ... 50 Sanitation ... ... ... ••■ ... 30 (ieneral ... .. .. ... ■•■ 20 (12.) In judging, the method of cultivation, condition of the trees, the -circumstances of each cultivation, tlie characteristies of the locality, and implements used, together with the condition of live stock, young cultiva- tion and manure heap, if any, will be taken into consideration. Competitors should also be able to answer any simple agricultural questions which may be asked on their work. ( 13. ) T)ae notice will be given before the judging commences in Marcli, 1920, and tl\e decision of the B jard will in all cases be final. 40 TRINIDAD AND TOBAGO BULLETIN. [XVIIL 1. Vegetable Prize Competition. (1.) Prizes will be awarded in the following classes : — Class I. \ acre of potatoes, with corn and blackeye, or pigeon peas or ^ acre of yams, with corn and blackeye or red peas. 1st Prize ... .. ... ... $ 15.00 '2nd Prize .. ... ... ... 10.00 3rd Prize .. ... ... ... 5.00 Class II. ^ acre of plantains with tannias or cassava and corn or blackeye peas. 1st Prize .. " ... ... .. $ 15.00 2nd Prize ... ... ... ... 10.00 3rd Prize ... ... ... ... 5.00 Class III. \ acre of Rice. 1st Prize ... ... ... ... $ 10.00 2nd Prize .. ... ... ... 6.00 3rd Prize .., ... ... ... 4.00 (2.) The Vegetable competition will be for period of May to September, 1919. (3.) No prizes will I)e awarded unless there are 25 competitors in Classes I and II and 10 competitors in Class III. (4.) In judging, the metliods of cultivation and condition (jf plants together with the circumstances of each cultivation, the characteristics of the locality', implements used, and the ability of competitors to answer agricultural questions relating to tlieir work, will be taken into consideration by the judges. (5.) Due notice will be given before the judging takes place in September, 1919. 0.) A competitor may enter one or all of these classes. (JENERAL. Entry to the CompctitionH Free. Entry Forms may be obtained on application to Agricultural Adviser, Scarboro, the Botanic Station, Wardens' Offices, or the Secretarj' of any Agricultural Credit Society. Entry Forms if addressed to The Agricultural Adviser, Scarboro, may be sent post free. All entries must be sent in on or before May 31, 1919. The Agricultural Adviser will visit all holdings entered for competition and give advice as to the best methods of cultivation free of any charge. The Agricultural Adviser will select the best competitor.? in each class to be visited by the judges. The Board may on the report of the judges, withhold or alter the value of any or all of the prizes if the cultivations entered for competition are not considered of sufficient merit. 1919. \ 41 AREA OP TRINIDAD AND TOBAGO. The following information by Mr. E. R. Smart, M.A., Engineer ia Charge of Surveys, as to the area of the Counties, Wards and Boroughs of Trinidad and Tobago, has been published in Council Paper No. 17 of 1919. The Counties and Wards are those as defined by Ordinance No. 1 of 1918 :— Trinidad. County. Ward. Acres. Square Miles. St. George... Diego Martin St. Ann's ... Blanch isseuse Tacarigua .. Arima Toco Cunupia Chaguanas... San Rafael... Montserrat Couva Valencia ... Matui-a Manzanilla Turure Tainana Pointe-^-Pierre Naparima ... Savana Grande Ortoire Moruga Charuma ... Cocal Cedros La Brea Erin Siparia Guayagua5'are Trinity Tobago 33,762 30,. 305 48,532 46,954 42,598 52-75 47-35 75-83 73-37 65-00 201,148 314-30 St. David ... 50,254 78-52 Caroni 29,413 48,783 24,535 37,376 22,060 45-96 76-22 38-34 58-40 34-47 162,167 253-39 St. Andrew 30,597 38,273 46,057 44,228 24,141 47-81 59-80 71-96 6911 37-72 183,296 286-40 Victoria 20,446 35,092 31,924 54,809 58,325 31 -95 54-83 49-88 85-64 91-13 200,596 313-43 Nariva 54,528 73,318 85-20 114-56 127.846 199-76 St. Patrick 36,3U0 .36,659 27,440 66,431 56-72 57-28 42-87 103-80 166,8,30 260 67 May arc 51,007 45,483 79-70 71-07 93,490 150-77 73,213 114-40 42 TBINIDAD AND TOBAGO BULLETIN. \XVIIL 1. Areas of Counties and Boroughs- Acres. Square Miles. 1. St. George 201,148 314-30 2. St. David ... 50,254 78-52 3. Caroni ... .. 162,167 253-39 4. St. Andrew ... 183,296 286-40 5. Victoria ... 200,596 313-43 6. Nariva .. ... 127,846 199-76 7. St. Patrick ... 166,830 260-67 8. Mayaro .. 98,490 150-77 9. Eorough of Port-of-Spain 1,793 2-80 10. Borough of San Fernando 670 1-05 11. Borough of Ariina... Trinidad Tobago ,., Total Trinidad and Tobago ... 588 0-91 1,191,678 1,862-00 73,213 114-40 1,264,891 1,970-40 1919.] RAINFALL BETUBN METEOROLOGY. 43- RAINFALL RETURN- JANUARY TO MARCH. 1919. stations. North-ivcst District. St. Clair — Royal Botanic Gardens Port-of-Spaiu — Colonial Hospital ,, Royal Gaol... Constabulary Headquarters St. Ann's — Reservoir Maraval — ,, ,, Constabulary Station Diego Martin — Constabulary Station ,, Waterworks ... ,, River estate ... Fort George Signal Station ... North Post „ Carenage Constabulary Station Carrera Island Convict Depot Chacachacare Lighthouse ■■• , Santa Cruz — Maracas District. Santa Cruz — Constabulary Station St. Joseph — Government Farm ,, Constabulary Station Tunapuna — St. Augustine estate Maracas — Government School ,, Ortinola estate ... ,, San Jose estate ... Caura — Wardour estate West Central District. Caroni — Frederick estate Chaguanas — Constabulary Station ,, "Woodford Lodge estate Carapichaima — Waterloo estate ,, McBean Cacao estate ,, Friendship Hall estate Couva — Exchange estate ,, Brechin Castle estate ,, Perseverance ,, • ,, Camden ,, ,, Milton ,, „ Spring ,, Constabulary Station ,, Esperanza estate Montserrat District. Brasso-Piedra — Mamoral estate ,, La Mariana estate Montserrat — Constabulary Station Brasso — La Vega estate Arima District. Arima — AVarden's Office ,, Torrecilla estate „ Verdant Vale estate San Rafael— Constabulary Station Guanapo— Talparo estate ... ,, El Quemado Estate Tamana— Sta. Marta estate ... „ La Carona estate ... San Fernando i c3 3 .^3 _; S i-t cS i o H Ins. Ins. Ins. • • •62 nil 1-78 •05 nil 2^14 •50 •06 2^24 •28 •06 1^87 •37 nil 2-16 "75 •04 1-59 •60 nil 2-63 1^04 nil 3^72 •69 nil 2-97 •48 nil 2-72 •76 nil 2-16 •23 nil 2-81 •79 nil 4-07 •24 nil 1^03 •51 •02 r70 •47 nil 4-28 •87 •10 1^11 •18 nil 0^91 •57 nil 1^11 •29 •05 3^10 •62 •11 2^66 •74 •17 1-83 •60 •09 1-66 3-15 ■57 1-39 •82 ■12 134 1^03 ■14 1^41 •62 ■21 1^32 •92 •43 1^69 1-22 •38 1^37 •73 nil 2^02 ,^. 1-01 nil 3^13 "•62 nil ^•97 •35 •38 1^57 •65 •05 2-82 •57 nil 2-60 •25 •48 2-80 1^45 •33 1^92 1'45 •13 1-95 2-62 •62 1^11 1^38 •46 1-39 •85 nil 0-91 1^26 •08 I^IO 1-70 ■76 1^66 2-45 ■19 2-15 . 2-25 ■23 2^95 2-17 •35 2-67 2-73 •4!) 2-77 .. 2-58 •46 3-29 •38 •40 1^12 "■27 "62 '•85 ■89 •06 1^62 •71 •13 2^24 •86 •08 2^68 •78 nil l-o5 1-77 nil 1-64 •• •82 •06 •79 Ins. 2-40 2-19 2^80 2^21 2-53 2^38 3^23 4-76 3-66 3-20 2-92 3^04 4^86 1-27 2^23 4-75 2^08 1^09 r68 3-44 3-39 2-74 2^35 5-11 2-28 2 -.58 2-15 3-04 2-97 2-75 4^14 2-59 2-30 3-52 3^17 3-53 3-70 3-53 4-35 3^23 1-76 2-44 4^12 4-79 5-43 5-19 5-99 0-33 1-90 1-14 2-57 3-08 3 •62 2-43 3-41 1-67 Org- Ins. 5-81 5^12 9-85 5^77 10 "77 8-44 7^02 7-63 6-42 6-80 5-16 7-07 6^52 2^56 7-10' 9-26 5^53 3^21 4^17 11^29 7^78 6^81 6^05 5^54 5-66 5-66 6^50 5-35 3^86 5^52 4^60 6^73 8-63 4^88 4-95- 13^31 11^29 8 -.34 1102- 6-39 9^91 7-70 13-74 10-05 13-35 16-88 14-33 6-93 6-15 7-04 5-87 9 •99 10-58 7-07 6-46 b-38 44 TBINIDAD AND TOBAGO BULLETIN. \XV1IL iri9.] KAINFALL RETURN- JAN. TO MAR., 1919.-cyNTn. stations. San Fernando and Princes Town T)i Naparinia — Palmi.ste estate ,, Lewis ville House ., Hcmiitage estate ,, Petit Morne estate Princes Town— Craignish estate ,, Cedar Hill estate „ Williamsville estate ,, Esmeralda estate ,, New Grant estate M C'onstabn]ar3' .Station ,, Hindustan estate ,, La Retraite estate ,, Malgretonte estate Friendship & Ben Lomond estates Los Naranjiis estate Poole — El Piosario estate South-west District. Oropuclie— Constabulary Station ,, Pluck estate Siparia — Constabularj^ Station ,, Alta Gracia estate Guapo — Adventure estate Point Fortin — Constal)ularj' Station Erin — I^a Ressource estate La Re-union estate Industr} estate Cedros — La Retraite estate ,, Beaulieu estate ,, Perseverance estate ,, St. Jfarie estate ,, Constabulary- Station ,, St. Quintin estate Icacos -Constance estate Irois — Government School South Const. Jloruga — Constabulary Station East Coast. Matura— La.Jnanita estate Manzanilla— Constabulary Station ,, Indrasan estate Sangre Grande — New Lands estate ,, Evasdale estate ,, Grosvenor estate ,, El Recundo estate ,, San Francisco estate Mayaro — Constabularj* Station North Coast. Blanchisseuse — Constabulary Station Grande Riviere — Mon I'laisir estat3 Toco — Aragua House „ Constabulary Station Point Galera — Light House Tohaiio. Tobago— Hermitage estate King's ];ay ,, Roxburgh , , Lure estate Botanic Station Government Farm Lowlands estate J'riendship ,, Riversdale ,, Bon Accord ,, strict. — [Contd.) Ins. 1-36 2-29 •69 1-05 •99 •89 1-57 1-09 roo ■G7 •98 1^91 1-21 "•91 F5.3 ]^16 1-31 ■70 1-44 •77 1-20 nil •41 •09 •99 •05 nil •08 •54 •50 nil •37 •81 f72 2^.52 2^44 2-(i3 2^49 2^04 2 •.54 2 13 1^71 2^22 2-01 r.33 1^15 2^-18 V\)(i 2-40 '•74 •30 131 Ins. •12 •08 nil •05 •24 •50 •50 •69 •38 1^12 •28 •58 F23 1-14 •33 •04 •53 "77 •94 nil nil •05 •38 •11 •11 •13 nil •09 •11 nil nil •88 •41 •35 •13 •34 •42 •33 •30 •45 nil •25 •49 •26 •06 1^12 1^10 •71 •20 •15 •08 •21 o H ■L so . o a CO o "' if. Ins. 2-24 2^57 1-78 2^39 2^22 y21 1^90 1^.38 2-39 1^17 2-40 3^00 •24 2 -.33 2^33 1-33 2^28 •95 2 •OS 1^96 2^07 •89 1^04 1^38 2^88 1-45 2^65 2 •OS 3^.35 1-77 1^00 3 02 r75 2^52 2 •48 2^08 1^99 370 3-26 2-23 2^89 2^00 4^32 3 23 2^12 I 2^00 3-17 2^78 2-42 •80 •77 2^96 Ins. 3-72 4^94 2^47 3^49 3^45 3^00 3^97 3^76 3-77 2^96 3 •66 5^49 2-68 4-33 3^99 2^53 4^12 2-48 4-40 2^73 3-27 •94 1^83 2^18 3^98 2^23 2^65 3^42 4^00 2^27 1-00 4^27 2^97 4^59 5^13 4-96 6^61 6^23 5^07 5^47 371 6-79 5^73 3^71 3^21 6-77 5^84 5^59 1-74 1^28 448 ; ns. 8^89 9^84 8-31 7-55 9-96 7 02 14 '•05 9^93 10-25 15^53 11-09 10^75 10-93 15 23 0^77 9^44 9^94 1011 7^34 8^53 9-77 10-37 14-23 12-04 14-41 13 10 13 29 15^28 .35-48 11-44 9^96 16^72 15^53 15^50 14 ^43 15^60 18-51 12-48 17-37 1613 22-02 19-37 17 -19 16-19 13 -50- 13 ^44 14^69 16^2!» 1421 6^82 4^66 7-73 9^87 0^53 {^Bulletin, DcjMrtmeat A^riauUiire, Trinidai • • > ■ > • .. April 30, 1919. Malgretout East Indian May 26, 1919. Picton : . . '. . • . May 30, 1919, Petit Morne (Palmyra) . . June 13, 1919. Tarouba (Ne Plus Ultra) . .June . 18, 1919. Union- Marabella ■ • * < • • • .. July 10, 1919. Harmony Hall ... ... .. July 10, 1919. Williamsville Eafc t Indian .. July 10, 1919. Indian "Walk ... . August 19, 1919. Toharfo. Pembroke ... •• • ••• • . June 18, 1917. Scarborough ... .. April 11, 1918. Delaford ... . August 26, 1918. l\Iason Hall... ... .. December 16, 1918. Moriah ... ... . .. Decembci 16, 1918. Charlotlcville • • . ... .. February 4, 1919. Plant Protection Ordinance. Chief Ivs2}Ccior {Acting) W. E. Broadway. ,F. W. Uricii. I Pi. O. Williams. Inspeclorti -' _ ,, ^ H. Meadex. II. a. Brunton. /J. A. Binder. Assislant Insj^cctors - J. Bl.ackman. [r. H. Le acock (Actg.) Reference Library. This Library can be consulted at the Head Office of the Department, St. Clair Experiment Station. It contains standard works on General Agriculture, Horticulture, Botany, etc., and books and periodicals dealing with Cacao, Sugar, Coconuts, Rubber, Cotton, Corn, Fruit, Tobacco, and other crops. V. BOARD OF ACxRICULTURE. President His Excellency the Governoi; Vice-President Tue Director of Agriculture Hon. Sir Norman Lamont, Bt. „ Sir G. Townsend Fenwick, K.C.M.G. „ C. de Verteuil. „ W. G. Kay. O.B.E. „ B. S. A. Warner, K.C. J. W. Arbuckle. J. P, Batx. J. Black. A. B. Carr. Joseph d'Aradie. L. de Verteuil. W. Greig. W. C. Jardine. J. J. McLeod, C. S. EOGERS. C. F. Todd. W. S. E. Barnardo. J. J. Carlee. Acting Assistant Director of Agriculture. Mycoloijht J- B. RoRER, M.A. * Eiilomolc'ji.-it F. W. Ukich, F.E.S., C.M.Z.S. Secrttary Jos. E. Seheult. (Y. D. Davies, Tobago. A'jrkuUia-al Advisers j C. M. Roach, San Fernando. \L. Mota, Rio Claro. Laboratory and Field Assistant W. Buthn. On leave for a vear from December, 1918. Standing Committees. Advisory Committee.— This consists of all the members of the Board ; five as a Quorum. Finance Committee.— The Director of Agriculture, Hon. Sir G. Townsend Fenwick, K.C.M.G., Hon. Carl de Verteuil, Messrs. Wra. Greig, J. J. McLeud and A. B. Carr. Cacao Committee.— The Director of Agriculture, Messrs. J. d'Abadie, Ludovic de Verteuil, J. P. Bain, A. B. Carr, W. C. Jardine and W. S. E. Barnardo. Sugar Committee.— The Director of Agriculture, Hon. Sir Norman Lamont, Bt., Hon. Sir G. Townsend Fenwick, K.C.M.G., Hon. W. G. Kay, Messrs. C. Forbes Todd, J. Black. J. J. McLeod and J. W. Arbuckle. Rubber Committee.- The Director of Agriculture, Hon. Sir Norman Lamout, Bt., Hon. R. S. A. Warner, K.C, Messrs. C. S. Rogers and Wm. Greig. Government Farm Advisory Committee.— The Director of Agriculture, Messrs. J. W. Arbuckle, J. J. ilcLeod, J. Black, C. Forbes Todd and Statistics Committee.— The Director of Agriculture, Hon. Sir Norman Lamont, Bt., Hon. Sir G. Townsend Fenwick, K.C.M.G., Messrs. W. C. Jardnic, Wm. Greig, A. B. Carr. Agricultural Exhibition Committee.— The Director of Agriculture, Hon. Sir G. Townsend Fenwick, K.C.M.G., Hon. W\ G. Kay, and Mr. Ludovic de V'eiteuil. VI. Department of Agriculture. GOVERNMENT STUD ANIMALS. TuE following are the arrangements for Septenal)er with regard to Sfcufl animals of the Government Farms in Trinidad and Tobago. Stallions. ,,, Where standing -^ GrooirJ's ^^"'^- ^-«^^- for Service. ^''- Fee. QuiCKMATOii. Thorough-bred ...Govt. Farm Trinidad ... $10.00 60c. Sru HoRRY...Thor'gh-bred Hackney.. Govt. Farm „ ... 5.00 GOc. Sir Horace. .Hrdf-bred Hackney .."...Govt. Farm „ ... 5.00 60c. R1LI.INGT0N Spartan. .Cleveland Bay. .Govt. Farm ,, ... 5.00 60?. Mauat ...Thorough-bred ...Roxburgh, Tobago ... 5.00 60c. Jack Donkeys. Monarch ...American Donkey ...Govt. Farm, Trinidad... $ 5.00 GOc. President ... Do. do. " ...Govt. Farm, Tobago... 5.00 69c. Barbados .Joe ... ...Govt. Farm, Trinidad... 1.20 60c. Bulls. A. — At Government Farms. TRINIDAD. I TOB.VGO. Cla^s. Fee. I Clans. Fee. 2 ruie-bred Zebu ... ^ 1.20c. ' 1 „ -Tersev ... '2.40c.| 1 Ture-bred Zebu ...§1.00 8 Half-bred Red i'oU ... 1.20c. 1 Half-bred Holstein ... 1.20c. ' 1 llalf-bred Guernsey ... 1.00 1 Half-bred Shoilhoni ... 1.20o.' B.— At Public Pastures or Estates. Flare. Class. Queen's Park S.ivannah 1 Half-bred Shorbhor.i ; 1 Half-bred Holstein. Mucnrapo Pastarc 1 Half-bred Shorthorn ; 1 Half-bred Guernsey. St. Clair E\-pti. Station 1 Half-bre 1 Holstein. St. Augustine Estate 2 Half-bred Holstein ; 1 Half-bred Guernsey. River Estate 1 Half-bred Zebu ; San Fernando 1 Pure-bred Holstein ; 1 Half-bred .Jersey. Harmony Hall Estate 1 Paro-bred Shorthorn. Arima 1 Half-bred .Tcrsey. Tobago, Friendship Est. 1 Half-bred Holstein. Pigs. At Government Farm, Trinidad. White Yorkshire, Pol ind Chini, Berkshire, Tamworth $1.03, and Attendant's Fee 25c.. .\t Government Farm, Tobago. ]5crkshire ... ... ... ... ...Fee 50c. At St. Clair Experiment Station. Berkshire ... ... ... $1.0J and Attendant's Fee 25j. POULTRY. Government Farm, Trinidad. Egg's of Barred Plymouth Rocks, Rhode Island Reds, White Leghorns ... ... ... $1.00 per doz. Great Kind Pigeons ... ... ... 40c. and 60c. per pair. Government Farm, Tobago. Eggs of Plymouth Rocks, Black Minorcas, Rhode Island Reds 48c. per doz. .Vlso Cocks and Pullets of livmouth Rocks and Rhode Island Reds. VII. Department of Agriculture. NURSERY STOCIT. Cacao, Limes and o.ny other plants required in large quantities for delivery for rarly planting in 1920 should be orlered now; address the Superintendent, St. Clair Experiment Station, or the Officer in Charge Botanic Station, Tobago. Special quotations at St. Clair for Cacao, Coffee and Limes grjwn from selected seeds are as follows : — Plants purchased in lots of 1 to 1,000 plants 3 cents per plant. Plants purchased in lots of several thousands 2 1 cents per plant. Plants purchased in lots up to 100 at 4 cents per plant. Plants purchased in lots up to 1,000 at $3.50 per 100. Plants purchased in lots of several thousands at $33.00 per 1,000. Tobago prices on application at the Botanic Station, Scarborough. Budded Avocados select varieties at 12 cents. Budded Oranges at 24 cents and Grafted Mangos at 24 cents should also be booked. Budded Cacao 12 cents each or in lots of over 100 at 8 cents. Limes from beds IJ cents per plant for lots over 100. A select stock is also kept of other fruit, ornamental and flowering- trees, palms, etc., a list of which can be obtained on application. Lar^-e orders must be booked six months previous to the date when the plants are required as large supplies are not kept on hand for casual demands. Delivered at Nu' series un crated. Delivered at Railway Station, Port - of- Spain or Queen's Wharf, securely packed in open crates. Board of Agriculture. SPRAYING CACAO, &c. From September to November is the time for spraying cacao trees for the prevention of thrips and black rot ; and early in the dry season for the Algal disease, die back, and cacao beetles. The Board of Agriculture has on hand a su^^ply of bluestone, which is sold to planters at 12 cents per })ound, also nicotine sulphate the best insecticide for thrips, which is sold at $10.70 per gallon. Men will be provided to superintend any spraying work which est;Ttes may wish to have done. Further information in regard to cost of spraying, etc., and applica- tions for bluestone and nicotine sulphate should be made to The Secretary, Board of Agriculture, Port-of-Spain. Vlll. PUBLICATIONS FOR SALE. The Bulletin issued quarterly, price sixpence per number or two sLillings per annum post free in the Colony. To other sulsoribors postage extra. VoL XVII. 191S. — Four parts, as issued, price 2?. Od. Chief Contents. — St. Lucia Lime Factory. Storage lilack-eye Peas (Illustrated); Fruits Trinidad and Tobago; Uses and culture of Dasheens (Illustrated) ; Coffea excelsa ; Yam cultivation ; Insec'-S Pests Vegetables (Illustrated) ; Agricultural Co-operatioji in the West Indies; Sugar Cane Experiments 1917-18 ; Cassava Experiments 1916-18 ; Food of the IMongoose; Strongylus; Citric Acid Contents of Trinidad Limes. Vol. XVIII. Ft. i.— Wither Tip of Limes (Illustrated) ; Yam Experiments 1918-19 ; Cultivation of Cotton; Nitrogen Content Cacao Soils ; Supposed Cure for Froghoppers ; Bedding Plants for Trinidad ; Fungous Diseases of Roses (Illustrated); Prize Competitions 1918-19. Our Local Foods : Their Production and Use, by W. G. Freeman, and R. O. Williams. — Price 3d. The Dasheen : Its Uses and Culture. — Illustrated. — Price 3d. Insects Affecting Vegetables in Trinidad and Tobago, by F. W. Urich. Symptoms of pests. Treatment, Preparation of Insecticides, etc. — Illustrated. — Price 3d. Life History and Control of the Cacao Beetle, 3 coloured plates, by P. L. Guppy. — Price 6d. Insect Notes for 1910-11. Miscellaneous Notes on Cacao Pests, by F. W. Urich. -Price 3d. Notes on some Insects affecting the Coconut Palm, one coloured plate by F. W. Urich and P. L. Guppy. — Price 3d. The Cotton Staineh Bug (Illustrated), by P. L. Guppy and Tliomas Thornton. — Price 3d. Rearing of the Vermilion Froghopper Egg Parasite, by F. W. Urich. — Price Id. The Sugar Cane Froghopper, six plates (3 coloured), by F. W. Urich. — Price 9il. The Surinam Witch-Broom Disease of Cacao, by J. B. Rorer. — Price 3d. The Froghopper Egg Parasite and its Colonization in Cane Fields, by F. W. Urich.— Price Id. The Mongoose in Trinidad and methods of destroying it, 2 plates, by F. W. Urich.— Price 3d. Annual Reports, Department of Agriculture, 1916 and 1917.— Price Is. 9d. each. All publications can be obtained from the Head Office of the Depart- ment, St. Clair Experiment Station, and sent post free within the Colony. The Bulletin is also on sale at Messrs. Muir, Marshall, and Davidson & Todd. Porls-of-Spain. OF THE DEPARTME^^T OF AaRIOULTTJUE Trinidad aixd Tobag-o. Part 2.] [Vol. XVIII. Frog-hopper Investig-ations.— In this number of the Bulletin considerable attention is devoted to recent aspects of the Sugar-cane Froghopper investigations. Mr. C. B. "Williams, the Entomologist in charge, had for some time been forming the conclusion that root disease played a more important part in the condition known as " blight " than was usually recognized. A.t his request Mr. W. Xowell, the M\-cologist of the Imperial Depax'tment of Agriculture paid a short visit fi'oni December, 1918 to February, 1919. Mr. Nowell's report is here given in full with an introductory resume by Mr. Williams. It has been arranged for Mr. Xowell to pay another visit this year so as to see the •canes at the time when the froghopper itself is usually at its worst. Pending anj- modifications which his second visit may cause the view held is that " blight " is often due not to froghopper attack alone, but to combined attack of froghopper and root disease, and that until some practical means of exterminating froghoppers can be found, careful attention should be given to improved agricultural methods and field sanitation which would reduce the damage done by root disease. This does not mean that the froghopper is no longer to be regarded as a serious pest. It is, and every etibrt should be Jiiade to get rid of it also. It means that the froghopper alone does not do all the damage ■commonly attributed to it, and that root disease is an important contributing agent. As the methods of dealing successfully with root disease are known, they should be applied, even if the necessary increased attention to cultivation, should require a temporary reduction in the area under cane cultivation. Agricultural Credit Societies.— Since the beginning of the 3'ear there has been a gratifying development of Agricultural Credit Societies. Mr. G. Moody Stuart has fostered them on estates of the Ste. Madeleine Sugar Company and twelve registered Societies are now at work in that area, bringing the total number of these Societies at work in the Colony up to nineteen. A mass m'^eting of the Ste. Madeleine Societies was held at San Fernando on July 26, when His Excellency the Acting Governor, the Hon. W. IMontgomerie Gordon presided. There were some 500 members •of the Societies present, who were addressed by Mr. G. A. Jones, Supei'intendent of the Cane Farmers of the Ste. Madeleine Company, and Inspector of the Societies, Mr. G. C. Wyatt, Mr. Jarvis, Manager Colonial Bank, San Fernando, Mr. Ludovic de Verteuil, Mr. W. G. Freeman, Acting Director of Agriculture and Registrar, and His Excollency the Acting Governor. 46 TBINIDAD AND TOBAGO BULLETIN. [XVIIL 2. Mr. G. C. Skinner of the Usine Ste. Madeleine is the Honorary Secretary of all these new Societies. Their formation, resulting as it is hoped will be the case, in active co-operation between the cane farmers, and also between the cane farmers and the factories augurs well for the future of the sugar industry of the Colony. The Eegistrar's address appears on pages 47 to 51. StaflF Changes- — Consequent on the return of two members of the staff from Active Service there have|been some changes in the Department. Mr. R. O'Connor has resumed his former post of Manager of River Estate, and Mr. L. Seheult, B.Sc, who acted as Manager during Mr. O'Connor's absence has been appointed Superintendent in place of Mr. J. de Verteuil. Mr. R. J. Link, formerly Overseer at the Government Farm, Trinidad, has on his return, been promoted to be Manager of the Government Farm and Oflticer in Charge Botanic Station, Tobago. He has been succeeded at the Government Farm, Trinidad by Mr. L. H. Patterson, who took up the duties of Overseer and Clerk on July 1, 1919. Ground Provisions Depot. — The trade of the Depot continues to increase, and the receipts are now about .£500 a month, compared with i£150 to ,£200 a year ago. The Committee has been informed by the Government that the Secretary of State for the Colonies, has " learnt with satisfaction of the success which has attended the efforts of the Committee." Empire Day Trees. — The present Director of Education, Mr. H. H. Hancock, M.A. has for the last few years done much to encourage the general improvement of the|School gardens of the Colony, by annual competitions, &c. On Empire Day each year the schools have been supplied with decorative or timber trees from the Royal Botanic Gardens. This year Mr. Hancock circularized the schools to plant a tree on Empire Day to commemorate the year during which Peace was signed. To mark this year's distributions as distinct from those of previous years, a plant of Tecoma pentajyJujlla or the Pink Poui was sent to all the applicants. As this tree is rarely met with it is hoped that in time to come it will serve as a reminder of this particular year to the schools to which it has been distributed. The following schools received one plant : — Guapo, Williamsville, Los Bajos, San Fernando CM. I., Princes Town, Grande Riviere, Indian Walk, Arima Boys, Toco E.C., St. Ann's Road, Longdenville, St. Joseph Government, Siparia CM., Cedros Government, Chaguanas Government, and Mt. Pleasant. The Pink Poui Tecoma pentaphijlla is a large tree closely related to the Yellow Poui so common in the hillsides and like it flowering when quite or almost bare of leaves. Each leaf is composed of four or five stalked leaflets of unequal size, the larger about 6 in. x 2\ in. The flowers borne in loose clusters are of a pale rose colour with a yellow throat, fading with age ; as the whole tree becomes a mass of blossoms the appearance is very ornamental. The individual trumpet shaped flowers are about 3 in. long, and open during March and April. Fine specimens of this tree can be seen in flower annually at Couva Railway Station, Tunapuna Recreation Gound, Errol Park St. Ann's, Port-of-Spain. It is a native of Tropical America. W. G. FREEMAN. 1919.] 47 AGBICULTUBAL CKEDIT SOC IETI ES. CANE FARMERS AND CO-OPERATION. By W. G. Freeman, B.Sc, A.R.C.S., Acting Director of Agriculture & Registrar of Agricultural Credit Societies. An address at a joint meeting of the members of eleven Agricultural Credit Societies, founded on the estates of the Usine Ste. Madeleine, held at the Victoria Hall, San Fernando, July 26, 1919. His Excellency the Acting Governor, the Hon. W. Montgomerie Gordon presided over the meeting at which about 500 cane farmers, all members of the Credit Societies were present. To-day's meeting of the members of eleven Agricultural Credit Societies founded in connection with the Usine Ste. Madeleine group of estates, honoured by the presence of His Excellency the Acting Governor marks, I trust, another definite step forward in the Agricultural progress of the colony. It marks the acceptance of the principle of co-operation, or working together for their common good, by the cane farmers, a large and important class of agriculturalists who are taking an increasing share in helping to maintain the sugar production of the colony. Ten years ago the cane farmers grew about one-quarter of all the canes ; they now grow about one-half. The future success of the industry thus evidently depends very largely on the continuance of good relationships between the factories and the farmers. We have just been celebrating the conclusion of Peace, a peace won by great sacrifice of life and money ; sacrifices which would not have earned their reward so soon had it not been for the close co-operation of the Allies. The war has taught man many lessons or perhaps has brought home again to him many truths which he was in danger of forgetting. One which I wish you this afternoon to take to heart and to practise, is that summarized in the old proverb " United we Stand, Divided we Fall." You cane farmers to attain success must be united, you must work together, you must co-operate ; the co-operation must be not only between cane farmer and cane farmer, but also between cane farmer and the factory owners. " United, the sugar industry of the colony will stand, divided it will fall." Some people may think now that British grown sugar is admitted into the United Kingdom at a lower import duty than foreign sugar, that all will be well and that they can now take things easily. The Empire, however uses far more sugar than it at present produces and although German and Austrian beet will doubtless never again be admitted on the old terms, we as sugar producers, will meet with very keen competition from producers in other countries, and to meet that competition successfully we must make ourselves more efficient than we are. Before the war the United Kingdom used every year some 1,800,000 tons of sugar, of which only about 75,000 tons came from British sources. In other words, for every .ton of British produced 48 TRINIDAD AND TOBAGO BULLETIN. [XVIIL 2. sugar used in the United Kingdom 23 tons of foreign grown sugar were used, and of theie 23 tons, no less than 18 came from Germany and Austria. So serious was the sugar situation that very shortly after the war commenced, the Hozne Government bought 1,000,000 tons of sugar, about as much as the colony exports in twenty years, and it continued to buy sugar on a similarly large scale during the duration of the war Now the Government was only able to get very little of the sugar from within the British Empire. It was compelled to go outside and some of the countries to which it went are those with which we have to compete in the future. CUBAN SUGAR OUTPUT. For example, Cuba, a West India Island not very far away from us, has made wonderful strides lately. Ten years ago Cuba produced about 1,500,000 tons. This year it is producing the enormous crop of 4,000,000 tons (of 2,000 lb.), as much as we produce in about 70 vears. Cuba has several mills each of which makes more sugar than the whole of Trinidad r.r/. in 1915-16 eleven mills ivaking 40-60,000 Ions, three making 60 to 80,000 and two 80-100,000. Cuba, although it has done so well is not resting content but is still working hard to develop its sugar industry and hopes, T see it reported, to reach 8,000,000 within the next ten years. We cannot dream of doing anything on this scale in Trinidad. We have not the land nor the labour. In 1917 our record yeai", we made nearly 71,000 tons and the cane farmers were paid over ^1,000,000 for their share of the crop. If we could increase our crop to 100,000 tons it would mean at least another $250,000 in the pockets of the cane farmers. To this we must increase tlie capacity of our factories ; increase the efliciency of our factories ; improve our cultivation, grow the best possible varieties of canes. The capacity and ethciency of the factories are not within your control as cane farmers. You may, however, rely on the owners doing all they can in these matters. When sugar is paying the more you make the greater the profit. With more efficient milling and a higher recovery of sugar from the juice, less canes are required to make a ton of sugar. This interests you because the factory which has to use 12 tons of cane.^ to m^ke a ton of sugar cannot pay so much for a ton of cane, as the one which can make a ton of sugar from 10 tons of the same quality cane. About 10 tons at the Usine Ste. Madeleine is the best we do in Trinidad but in some other countries a ton of sugar is made from eight or even less tons of cane. In countries where cane farmers work on a larger scale than here it is possible to fix a sliding scale for canes according to the richness of tlieir juice. With our small areas that is not practicable but the factories can control the situation to some extent by refusing to take, or by giving a lower price for canes known to be poor kinds. The way in which you cane farmers can earn more money and make more profit is mainly by giving more attention to your cultivation and so getting more canes to the acre. A PLEA FOR INTENSIVE CULTIVATION. There is a tendency all too common in Trinidad for many planters both large and small to attempt to culti^•ate a larger acreage than they 1919.\ CANE FABMEES AND CO-OPERATION. 49 can do thoroughly. The result too often is very little profit. The man who, if he would cultivate one acre well, might make a good profit, spreads his available labour and money over two aires, and often makes less profit than he would from the one. The Board of Agriculture last year in this district, and again this year at Couva, Chaguanas and Caroni, is endeavouring by means of Cane Farmers' Prize Competi- tions, under the charge of one of its Agricultural Advisers, Mr. Roach, to help the farmer to get better crops, and so more money for his work. This year the Usine Ste. Madeleine has its own officer, Mr. Jones, Superinten lent of Cane Farmers, doing similar work, and is also offering prizes. It is a competition in which you can all g3t prizes, for a better return of canes is a good prize in itself. In speaking to you on this subject, I would remind you that the Department of Agriculture practices Cane Faiming. During this last season at St. Augustine Estite, we, as others, have been unable to get any artificial manures, and so we have to rely on pen manure, and attention to cultivation. Tlie following figures of our results mxy be of interest to you. Tons Cane Acres. ^^^. ^(.^g^ Plant canes ... ... 12-6S ... ... 23-70 First ratoons... ,.. 17-09 ... ... 19-94 ■ Second and other ratoons... 39-33 ... ... IT'lO Total 69-95 acres with an average yield of -20-07 tons to the acre. Now in extending or improving your cultivations, buying additional stock, putting up the new buildings, buying better tools, implements and artifical manures, many of you want money. That is money in addition to what the Estate is ready to advance you for the ordinary cultivation of your canes. It is money which if well spent will bring you in greater returns than you could otherwise expect. Small cultivators of the Colony who are not members of Agricultural Credit Societies know that it is difiicult to borrow money for such purposes at reasonable rates of interest. They usually are compelled to go to the money lender, who charges such high rates of interest, that the borrower often has little chance of paying back the lo m, much less of making larger profits from its use. GROWTH OF CREDIT SOCIETIES. The principal object of these Credit Societies is to help you to borrow money at reasonable rates of interest. We had to work a good many years to get such Societies started here, as my friend Mr. Ludovic de Verteuil can tell you, for he was one of the first to try to get these Societies established in the Colony. It is probably 30 years since the first efforts were made. Where there was not active opposition there was often lask of interest, and it has taken very much longer to conquer this opposition and apathy than it did to beat the Germans. Their development in this district is very largely due, as you know, to the personal interest of Mr. Moody Stuart, who has also in other ways, including the introduction of a sliding scale for your canes, helped to put cane farming on a better basis. Associated 50 TJRINIDAD AND TOBAGO BULLETIN. [XVIIL 2. with Mr. Moody Stuart in this good work are Captain Mark Moody Stuart, whom we are glad to welcome back from active service, Mr, Forbes Todd, the Managers of the various estates, Mr. Jones and last but not least, Mr. Skinner, who has undertaken the duties of Hon. Secretary of all your Societies. We have thus succeeded at last having now 12 societies in Trinidad and six in Tobago, and they will, I believe, increase and flourish to the lasting benefit of the smaller cultivators of the colony, and through them of the large estates and of the whole community. The principles on which they work have been carefully explained to j'ou all. I will therefore only deal now with a few of the more important points. MEMBERSHIP. Not ever'j'One can join a Credit Society. He, or she must be an owner or renter of land in the particular district in which the Society works, and must be a person of good character. The latter point is very important for you to remember. Do not admit people who are known not to be honest, and hard working. If you do you may find later, if you have let them borrow money, that they do not put it to proper use, and fail to repay it. Every person of this character is a danger to your Society, and may cause you to be liable for his debts. Let it be an honour to be a meniber of an Agricultural Credit Society, so that membership may show tiiat you ai'e recognised by your neigh- bours as being a person of good character. OFFICERS AND COMMITTEE. These are very important positions and on the selection of good men much of the success of the Societ3' will depend. All your officers and committee men give their services free, and the thousands of cultivators in Credit Societies throughout the world have great reason for thanks to their officers for their disinterested work. Work loyally and honestly with them and make their task as easy as possible. Here you have been greatly assisted at present by the fact that many of the managers of your estates have been read\- to accept responsibilities and duties as Trustees, &c., that Mr. Skinner is working hard as Secretary of all ^our Societies, and Mr. Jones as Inspector. SOCIETY BORROWING MONEY. Why can the Credity Society borrow money from the Colonial Bank, as you do, on better terms than each of you alone? The reason is this. The Bank does not know each of you separately, and cannot afford to have Inspectors all over the Colony to visit each holding, to find out whetlier the security is good and whether the money, if lent, is being put to proper uses. The Bank will however lend to 50 or 100 of you, selected people of good character, joined together in a Society, registered by the Government and under Government inspection, on the condition that all the members together are liable for the money lent the Society. Y'ou settle at your general meetings how much you will borrow ; for that reason you must attend regularly all meetings that are called, because what is agreed on at these meetings is binding on you all and 1919.\ CANE FARMERS AND CO-OPERATION. 51 -even if you leave the Society you are still responsible for debts if con- tracted whilst you were a member. LOANS TO MEMBERS. When the Society has borrowed money— it may be $500, ?il,000, $2,000, you must remember it is for all practical purposes your own money, and you must take care to lend it out properly. This you do through your own Committee. Only members of the Society can borrow and each has to state in writing what the money is wanted for. The Committee decides whether the use for this purpose is likely to be profitable and only lends the money if quite satisfied. It is here that you can exercise the control impossible to a distant bank. In each Society you are all neighbours, know something of each other's affairs, can judge whether the purpose stated is true and the use of the money likely to be profitable, and, most important, you can easily see whether the money is used for the particular purpose stated. If you find it is not being properly used, the loan can, and should be, promptly recalled. At the same time the Committee, knowing the circumstances of each one can extend a loan if sickness, bad season, diseases or pests or other good reason really prevent the borrower from repaying it at the promised time. RESERVE FUND. Build up a good reserve fund out of entrance fees and profits as soon as you can. With this to fall back on, you can later reduce the rate of interest you charge members. GENERAL. There are other points I might dwell upon but they are all matters of less importance. What I want you to remember particularly are these : Admit as members only people of good character. Attend your general meetings. Understand what you are doing ; ^vhat sums the Society is borrowing ; for you are all personally liable for their repayment. Select good men for your Committee, because you entrust to them the lending out of the money you have borrowed, money for which you are responsible. Help the Committee in seeing that loans are used for the purposes stated. Be prompt in your repayments of any loans and if impossible for special reasons for you to repay at the time an instalment is due, go to the Committee at once and explain why you cannot carry out your promises. If you keep these few principles steadily in mind and work honestly with one another, your Society will be a success, and you will find it a real help to you at the time when you need money to carry out some useful purpose. Moreover, you will find the Credit Society a means of making the cane farmer more prosperous, and so increasing the welfare of the sugar industry of the Colony and of the Empire. 52 THIN WAD AND TOBAGO BULLETIN. [XVIIL 2.- THE RELATION OP ROOT FUNGUS TO PROGHOPPER BLIGHT OF SUGAR-CANE IN TRINIDAD. By C. E. Williams, M.A., F.E.S., Entomologist in Charge of Froghopper Investigations. There appears (pages 57 to 69) a report by Mr. W. Nowell,. IVIycoIogist to the Imperial Dejiartment of Agriculture for the AVest Indies, on a visit which he paid to Trinidad in December 1918 to February 1919 to study the occurrence of Root Disease of Sugar-cane in this island, particularly in relation to the condition known as " blight" or " Froghopper blight." As Mr. Nowell's visit took place owing to my special request to the- Froghopper Committee, I have been asked by Mr. Freeman, Acting Director of Agriculture, to give a short summary of the past views on the causes of the disease, the conclusions that I have come to, and. in general, of the events that led up to Mr. Nowell's visit. The present accoimt is by no means complete as there arc a large number of critical and important experiments and observations that I hope to make during the coming season. It will however serve as an introduction to the fuller report that I hojie to give next year at the termination of my engagement. HISTORICAL. Blight lias been known in Trinidad since the middle of the last century ; at that time, however, critical investigations were seldom made and the damage was more or less vaguely attributed to unfavour- able conditions. H. Cruger in a report dated 1863 (published in Agricultnral Ixccorcl, Trinidad. YII. Oct. 1892, 78) considers cue of the most important of these as " a want of rain at a certain period." .J. H. Hart {Agricultural Hccord. II, 1890, 156) reports on an outbreak of blight at Chaguanas in 1889, and is the first to mentio)i the Froghopper, which he considers as the prime cause of the injury. There seems to have been no serious outbreak of blight between this time and 1906, which year was the first of a series of severe attacks. In this year Hart {Bull. Misc. Informatio77, Botanic Dejjt. Trinidad VII. 152) reprinted his earlier report and laid more stress on the presence of root fungi in the blighted areas. He says "on some estates the canes were badly infested with Root Fungus {Marasmius) and on these the attack of Froghoppers appeared more pronounced than on other fields where better health prevailed." In the same jear A. E. Collens made two reports on outbreaks of blight at Harmony Hall and Brechin Castle, in which he notes the presence of both root fungi and Froghoppers, and, without definitely stating which he believes to be the more imjiortant cause, he gives directions for control which deal with both agents. In 1909, after three severe outbreaks in successive years. Hart {Proc. Agr. Soc, Tiinidad and Tobago IX. 32-40) has changed his opinion as to the importance of the Froghopper and now considers that root fungus is at least as important as the insect, the Froghopper being however a contributory cause. He writes ''■Marasmius is usually to be 1910.] FBOGHOPPEE BLIGHT OF SUGAR CANE. 53 found among canes that are attacked by Froghoppers, and ia usually absent when the canes are not affected" and later " It is ro.v generally accepted that insects .... attack canes infested with fungus disease more rapidly than healthy plants, and that inclement seasons lead to the spread of diseases and consequently to attacks of insects." Collens in the same year {Proc. Agr. Soc. Vill. £63) writes that the cane " is first attacked by disease and efforts to .... throw off . . . . are rendered ineffective by persistent attacks of froghoppers." Carmody {Proc. Agr. Soc. IX. 1909. 107) writes " whenever Frog- hoppers are unusually abundant, the canes on closer examination have been found to be diseased from other causes, and the juice is abnormally acid." He suggests that the acid juice may make the canes more attractive to the Froghoppers. On the other hand other authorities were convinced that the Froghopper is the chief cause of the damage. J. Black {Proc. Agr. Soc. YIII. 1918, 565) writes "I have seen no case of blight where the froghoppers have not first been present in large numbers." J. B. Borer, who had just started his work as Mycologist to the Board of Agriculture writes (Report of the Mycologist August 13, 1909) " The disease called blight here is quite distinct and different from the root fungus in many ways .... In many worst blighted fields root fungus is present only in very small quantities, or is altogether absent." F. W. Urich, Entomologist to the Board of Agriculture writes {Bull. Dcpt. Agr., Trinidad and Tobago. IX. 17) " canes attacked by root disease, as well as those entirely free from it, were blighted .... In every case Froghoppers were present." From this time onwards, until quite recently, during the investiga- tions of Messrs. Rover (1909-18), Urich (1909-1919), Gough (1910-1911), Kershaw (1912-13) and Guppy (1912-14), more and more attention has been paid to the role played by the Froghopper and research was almost entirely directed to its reduction or control. It is true that Gough in his final report {De])t. Agr., Circular No. S. 1912. 11) says "there is evidence to show that fungoid diseases of the cane predispose it tO' an attack of Froghoppers," but apart from this there is scarcely any further reference to the possible association of the two diseases. During the first eighteen months of my own work on the Froghopper (1916-1917) I was working, by instructions, on the introduction into Trinidad of new enemies to reduce its numbers, and during that time I had a few opportunities of studying the blight in the cane fields. In August 1917 it was decided to abandon, at least temporarily, this branch of the work and I was instructed to study the Froghopper in Trinidad " from a wide biological standpoint." The year 1917 was unfortunately marked by a very severe outbreak of bhght, and I soon found that, although Froghoppers were invariably present in blighted fields, yet there was not a strict correlation between the numbers of insects present and the extent of the damage. Certain fields appeared to survive a severe infestation of froghoppers, while others with much fewer were severely damaged. This disparity became very obvious when an attempt was made to find how many Froghopperi were required to cause damage. 54 TRINIDAD AND TOBAGO BULLETIN. [XVIIL 2. It was not until the wet season of 1918 that I was able to get any accurate information on this question, but the results when obtained confirmed the suspicions of the previous year. Two methods were used to get an estimate of the number of Froghoppers present. The first consisted of counting the number of Froghoppers visible on a given number of stools in a field and then calculating the probable total per acre. The second method, which is purely comparative, consisted of finding the number of adults caught in similar light traps placed in different fields. Both methods are subject to many errors, but the results were too striking to be explained in this way. Fields were badly damaged when only about ten adult froghoppers per stool could be seen at the height of the brood; other fields in which thirty or forty adults per stool -could be seen were only slightly injured. One field in which 20,000 adult Froghoppers were captured in one night in four light traps suffered but slightly, while a field in which the numbers never rose above 3,000 was almost completely destroyed. Results of this kind were a very strong indication that some other factors were involved besides the mere numbers of the Froghopper. Many of these were known — the age of the cane — the soil — the rainfall — manurial treatment — drainage, &c., but although the effect of all these could be seen they were of themselves insufficient to account for the differences found. Attention was then turned to the possible association of the Froghopper with other insects or with fungi or even the possibility that it introduced some toxic substance into the cane plant. No insect could be found whose presence would explain the conditions, but when a search was made for fungi it was immediately seen that certain species of root fungi were in almost more constant association with the condition known as " blight," than the Froghopper itself. In September 1918 Mr. J. V>. Ilorer visited witli me certain fields which had led me to these opinions and agreed that in nianj' of these root fungi were responsible for the greater part of the blight. In October 1918, as Mr. Ilorer was leaving the country, 1 requested the Froghopper Connnittee to invite the co-operation of Mr. Nowell, Mycologist to the Impei'ial Department of Agriculture. As a result he visited Trinidad from December, 1918 to February, 1919 and the follow- ing report gives the results of his observations. They are I think of particular value, as he has had considerable experience of the damage due to root fungi in islands where the Froghopper does not occur. In view of the results of these various investigations I think it can be safely said that root fungi are responsible, directly or indii-ectly, for a considerable portion of the damage generally attributed to Froghoppers. RELATION BETWEEN FROGHOPPER AND ROOT FUNGI. There remains the question as to the relation between the Froghopper and the root fungi. Is each independent of the other '? Does the presence of one predispose the cane to the attacks of the other ? Or are both dependent on some similar environmental conditions. JL919.'\ FBOGHOPPEB BLIGHT OF SUGAB CANE. 55 Several different types of damage are possible: — (1.) Caused by Froghopper alone. (2.) Caused by Root Fungi alone. (3.) Eoot Disease followed by independent Froghopper attack. (4.) Froghopper followed by independent Root Fungi. (5.) Froghopper attack resulting in increase of Root Fungi. (6.1 Root Disease resulting in increase of Froghoppers. 1. We have at present no direct experimental evidence that Frog- hoppers alone can cause blight. Several innoculation experiments have been tried by various experimenters but all gave negative results, except one in which conditions resembling blight were produced in potted Para grass by a heavy infestation of froghoppers. (Heriot. Proc. Agr. Soc. VITI. 1908. 550). There is also still some doubt as to whether it is the nymph or the adult which is the more dangerous. Experiments to test these points will be carried out this season. In spite of this lack of experimental proof, thero is, however, no •doubt that Froghoppers alone, in sufficient numbers, can cause great damage. The severe loss occasioned to plant-canes in years of heavy blight must be due almost entirely to the Froghopper, as root fungi are seldom found in any quantity in canes during their first year of growth. In such cases, as Mr. Nowell has pointed out in his report, recovery is more rapid than when the situation is complicated by the presence of root fungi. In addition we know that conditions similar to blight can be produced in other crop'^ (e.g. grass and corn) and in other countries (Colombia, Cuba, British Guiana, &c.) in constant association with Froghoppers. 2. Damage due to the root fungi alone is sufficiently well established to need little comment. One of the features of such an attack is its close dependence on external conditions such as the rainfall, soil, and general health of the plants, and such a dependence is very noticeable in many of the Trinidad outbreaks. 3-6. Tn nearly all the cases of blight in Trinidad both Froghopper and root fungi are present and it becomes the question to decide whether either one of them is responsible for the presence of the other, which is the cause of the greater part of the damage, and which can be most •easily reduced. In the limits of the present preliminary report the evidence for and against these various conditions cannot be detailed, but after two years observations in the field I am inclined to think that the most usual condition is No. 5 — that is an attack of P\-oghopper followed by, and at least partly responsible for, an attack of root disease. After the Frogho))pers have died out the root fungi persist and may cause the damage to increase out of all proportion to the number of Froghoppers originally present. This persistence of the damage after the Froghoppers have disappeared is a very marked feature of many of the attacks of bliglit in Trinidad and is one of the strongest arguments that the insect alone is not responsible for all the damage. 56 TBINIDAD AND TOBAGO BULLETIN. [XVIIL 3. I hoi^e to show in a later report on the relation between blight and rainfall, that the most serious outbreaks of blight have occurred in years when the canes first damaged by the association of Froghopper and root fungi have been further held back by drought at the time of the year when they might otherwise have recovered. PEACTICAL APPLICATION. The diseases due to root fungi are well known throughout the world, and have been found to lend themselves to treatment the main aspects of which are outlined in Mr. Nowell's report, with whose suggestions I thoroughly agree. In those cases in which the Froghopper is believed to be responsible for the beginning of the outbreak, it can be argued that the best control would be to destroy the insect itself and so prevent the evil starting. This is undoubtedly true, but after ten years work we are still without any certain and direct means of destroying the Froghopper. There is no knowing at what time some such niethod may be discovered, but until then much can be done by reducing the amount of root fungus present, so that the Frogliopper may have no powerful ally to help him in his destruction and to carry on liis work after he is gone. If one field will give a reasonable cro]:) with thirty Froghippers per stool, there is no reason why ten Froghoppers per stool in another field should be allowed to destroy h. It is not too much to say tliat fifty per cent, of the damage at present caused by blight could be prevented without any alteration in the number of froghoppers. There will still remain the outbreaks in which the damage is due entirely to the abnormal numbers of insects present, and for the prevention of these we can only look forward to the day when co-operation of the investigator and the planter has produced some reliable and practical method for their treatment. .Time, 1919. 1919.] 57 BEPORT ON AN INVESTIGATION OP PROGHOPPER PEST AND DISEASES OP SUGAR-CANE IN TRINIDAD. •!) By W. Nowell, D.I.C, Mycologist, Imperial Department of Agriculture for the West Indies. With a covering letter by Sir Francis Watts, K.C.'M.G., D.Sc, &c. Commissioner of A.griculture for the West Indies. ImpepvIal Department of Agriculture for the West Indies, Barbados, March 4, 1919. Sir, — lu continuance of our correspondence bearing upon the question of diseases of sugar-cane in Trinidad I now have the honour to forward the report by Mr. Nowell as the result of the observations made during his visit to Trinidad in December and January last. 2. When Mr. "Xowell's services were asked for in this connexion th? investigations, which had been in progress for some time, had reached a stage when it was felt that other factors than the presence of froghoppers were at work causing the serious loss of the sugar crop which was complained of. Mr. Xowell's investigations iuWy confirm this impression: he finds that the position is complicated by the presence of fungus root disease of the canes, but his observations more particularly goto show that the diseased conditions generally met with are attributable mainly to defective methods of agriculture, and that froghopper and root disease are to be combated rather by general methods of agricultural improvement than by application of specific remedies. 3. I may add that I entirely concur in the views expressed by Mr. Nowell and I venture to hope that his report will prove of material service to those engaged in the sugar industry of the colony. I venture to suggest that it will be well if steps can be taken to give early publicity to Mr. Nowell's report while matters connected with his visit are still fresh in the minds of the agricultural community. 4. As requested in Your Excellency's letter No. 787/1915A of January ^8, 1919, I hope to be able to arrange that Mr. Nowell mxy pay another visit to Trinidad in September next in order to continue his observations concerning these diseases of sugar cane. I have, &c., FRANCIS WATTS, Commissioner of Agriculture for the West Indies, His Excellency Sir John li. Chancellor, K.C.M.G., Govex-nor, Trinidad. (1.) Reprintea from Triiuiad and Tobaijo Counci! Paper 'So. 39 of 1919. 58 TBINIDAD AND TOBAGO BULLETIN. [XVIII. 2.. Report on a visit to Trinidad December, 1918-February, 1919. Imperial Commissioner, In accordance with your instructions I left Barbados by the Iloj^al Mail Steam Packet ■' Caraquet " on December ]6 for Trinidad, arriving in Port-of-Spain on December 18. I reported myself to His Excellency the Governor on the following day. The question of my return was discussed with His Excellency and the members of the Froghopper Committee on January 16, and the approval of that body was obtained for my return by the Royal Mail Steam Packet " Chaleur," leaving Trinidad February 1 and arriving in Barbados February 3. 2. In company with Mr. C. B. Williams I visited all the areas which were considered likely to provide information on the subject of sugar cane failure. 3. Towards the end of my stay, with the permission of His Excellency the Governor, I spent a few days in the investigation of the so-called root disease of coconuts, as to which a separate report will be made later. 4. The situation which led to the request for my services I under- stand to have arisen as follows : Mr. C. B. "Williams, Entomologist in Charge of Froghopper Investigations, had found that the prevalence in sugar cane fields of the condition known in general terms as blight, in many cases did not correspond with the severity of froghopper infesta- tion. In some cases of severe injury the insect was never present in numbers which appeared to be at all adequate to explain the damage, while in others froghoppers were present in large numbers with much less visible effect on the cane. Mr. Williams reached the conclusion that an additional factor must be involved in the production of blight, and this- he came to believe was root disease of fungoid origin. For this reason he desired the co-operation of a mycologist with experience of the effects- of root disease in places where no complications with froghoppers exist. 5. At the time of my arrival in Trinidad the froghopper infestation was practically over for the durati on of the cuiTcnt crop, and I nowhere saw more than a scanty and scattered remnant. The period of my visit, which covered the last two or three weeks of the wet season and the beginning of the dr^-, was the "most suitable for the estimation of the position held by root disease in the final condition of blighted fields, though it would have been more satisfactory if I could have approached the subject with personal experience of the immediate effects of frog- hopper activity. 6. From an early stage in the investigation, and without prejudice to conclusions as to the ability of the froghopper to produce serious damage, it became evident that the name of the insect was in pojiuiar use to cover practically all the causes which may operate to produce an unhealthy appearance in standing canes. In many fields other adverse conditions were present to a degree which I should unhesitatingly accept as sufficient to account for depression or failure, without any need to bring in the froghopper as an agent. Such conditions do, in fact, regularly produce similar results in all the islands with which I am 1919.\ INVESTIGATION OF FROGHOPPEB PEST, <£c. 59 familiar, in the absence of the froghopper and often in the absence of notable insect injury of any kind. 7. It is the first necessity of success in meeting the various aspects of blight that a closer discrimination should be applied to the estimation of the causes which in any particular case produce it. For this reason the concentration of attention in recent years on the purely entomolo- gical aspect of the subject, while it has so far failed to bring the hoped-for relief, has delayed progress in more promising directions. 8. It is the main object of the present report to contribute to the understanding of the widespread type of failure of the cane crop to which the non-committal name of blight is the best to apply. It ranges, in the examples exhibited to me, from a condition in which whole fields contain nothing but stunted and worthless stools, the cultivation of which has been abandoned, to merely unhealthy fields which will give, in various degrees, reduced returns. There is another type in which the appearance of health is maintained, but development has at some stage been so arrested that the canes look months younger than they really are. In the definitely unhealthy fields the existence of root disease is general, and its prevalence as a rule appears proportionate to the severity of the damage experienced. 9. The key to the correct appreciation of root disease is the fact that both its onset and its persistence depend on a condition of weakness or debility in the cane, that is to say the existence of root disease pre-supposes some unfavourable circumstance which enables it to take effect. The list of the possible pre-disposing causes covers all the adverse conditions to which sugar cane is subject, and a complete discussion of the reasons for its prevalence involves a survey of the whole field of cane cultivation. I propose to deal in three sections with the general nature of root disease, the apparent reasons for its epidemic occurrences in Trinidad, and the means which may be adopted for its reduction. THE NATURE OF EOOT DISEASE. 10. The name root disease has come to have specific application in the case of sugar cane to conditions which arise from the invasion of the roots, and in severe cases the underground portions of the stool and the young shoots, by the mycelium of certain fungi which normally exist on the decaying cane material in or about the soil. 11. The fungi concerned in Trinidad as in other parts of the West Indies are mainly two, or as it would appear to be more accurate to say, two groups, each comprising two or more closely allied species. {a.) The Marasmius group. — This is usually represented by Marasmius Sacchari, but the fructifications of other species of Maras- mius are sometimes seen, occurring under conditions at present indistinguishable. The fruiting bodies, which are developed only under very moist conditions, are small papery toad stools usually less than half-an-inch across. They quickly dry up and disappear on a sunny day, and are rarely seen unless specially sought for. The mycelium of Marasjnius Sacchari is more or less distinguishable by the appearance it produces of the leaf sheaths being stuck closely together as if with flour paste. There is no approach to the definite and easily recognisable form pertaining to the group next to be described. •60 T BIN ID AD AND TOBAGO BULLETIN. [XVI 11. 2. (h.) The Odoniia (fronp.^k white mycelium, easily distinguishable from that of Marasmius by its feathery pattern of growth and the production of abundant stellate crystals of calcium oxalate, has long been known as apparently capable of producing effects similar to those of Marasmius. It has been commonly refei-red to as the stellate crystal fungus, and, as a mycelium of unknown affinities, was given the name Himant'ia stellifera by J. E. Johnson. Eecently Dr. Burt has described the fructifications of Odontia Sacchari and O. saccharicola from Porto Bico material : two closely related fungi which produce their spores on cane trash in a close lying granular, buff-coloured layer hardly distinguish- jible without the {dd of a lens from the surface of the dry trash itself. J^rom llie constant association and the apparent organic connection of Odontia fructifications with the typical stellate crystal mycelium I was led by observations in Trinidad to believe that the two belonged to the same fungus, and I find on reference to Cane Fungi of Porto Rico by J. R. Johnston and J. A. Stephenson that /he same suggestion has already been made by those authors. The connexion may be regarded as highly probable. 12. The Odontia type of fungus appears to be much more common in association with root disease in Trinidad than the Marasmius type. The parasitism of both requires detailed investigation. So far as our present knowledge goes their modes of operation may be treated as the same and their effects be referred to without discrimination as root disease. For the sake of simplicity in presentation the myceUum of either or both will l:c referred to as root fungus. 13. Und.M- ceitain circumstances, to be detailed later, root fungus is commonly \ resent in healthy fields carrying on an inconspicuous existence. Under conditions favourable to vigorous growth of the cane it is practically harmless, but when the vitality of the plant is depressed and growth is slow the presence of the fungus becomes serious. It enters the growing tips of the young roots, distorting tliem, stopping their development and causing them eventually to die. It envelops the young shoots in their various stages, hindering their development by cementing the leaf-sheaths, and in severer cases it infests internally the buds, the young shoots, and the underground connections of tlie stool, and enters to some distance the bases of the developed canes. 14. The general effect produced by the disease is that of shortage of water, which is brought about by interference with absorption by the roots and conduction by the underground stem system. The leaves of affected shoots have their edges rolled inwards when those of healthy plants are expanded; they eventually turn brown from their edges inward, and in order from below upwards until the shoot is withered to the top. The trash, where it has not been stripped, is cemented firmly around the lower joints of the canes, and under it matted roots occur up to a foot or more from the ground, sent out in an endeavour to find the necessary water. When a clnir.p is infested early it has a characteristic stunted appearance and several or many of the shoots may b3 dead and ..J. Black, late Attorney and General Manager for Waterloo, Exchange, Camden, &c. J.B.H. ... J. B. Harrison, Director of Science and Agriculture, British Guiana, J. de Y. ...J. de Verteuil, Superintendent of Field Experiments, Department of Agriculture, Trinidad & Tobago. J.G. ' ...J. Gilbert, Manager of Caroni Estate. J.J.H. ....I. J. Halliday, Manager of Picton and Wellington Estates, Usine Ste. Madeleine. J.K. ...J. Knox, Manager of Waterloo Estate. J.McP. ...J. McPherson, late Manager of BenLomond and Friendship Estates. J.R.B. ...J.R.Bovell, Superintendent of Agriculture, Barbados. J.R.F. ...J.R.Foster, late Manager of La Fortunee Estate. J.W.A. ...J. W. Arbuckle, Manager of Brechin Castle Estate group. L.A.B. ..,L. A. Brunton, Asst. Superintendent Field -Experi- ments, Dept. of Agriculture, Trinidad & Tobago. M.M. ...M. Maiden, Manager of Williamsville Estate, Usine Ste. Madeleine. P..de V. ...P. de Verteuil, Attorney of Woodford Lodge, Estate, E.B.McF. ...R. B. McFarlane, late Manager" of La Fortunee Estate. W.H. ...W. Howaal, late Manager of Orange Grove Estate. W.H.B. ...W. H. Bolton, Manager of Tarouba Estate, Usine Ste. Madeleine. 72 TRINIDAD AND TOBAGO BULLETIN. [XVIIL 2. BOURBON. A stout long-jointed yellowish green cane. Leaves somewhat dark and broad. Internodes cylindrical, no channel. Bud rather large round pointed. Shallow rooted with a tendency to trail. One of the oldest varieties, introduced from Otaheite in the eighteenth century. Began to " break up " owing apparently to fungus diseases at the end of the nineteenth century and has since then been almost ■entirely replaced by seedhngs. Blight.— BsAly damaged, Craignish 1918 (C.B.W.), Caroni 1908 (.T.G.) Badly damaged as plants and ratoons Woodford Lodge 1912 (P. de V.) 10 acres badlj- damaged Harmony Hall 1912 (W.H.B.) Generally worse than the others (G. H. Hill). Have seen badly damaged (.J .R.F., J.K., J.B., M.M.) Have seen badly damaged but stands attack about as well as any (J.G.) Slightly damaged Forres Park 1912 (F..J.M.) Slight damage St. Augustine 1917 (C.B.W.) Slightly damaged Caroni 1912 (J.G.) Not damaged Plein Palais 1912 (A. D.L.), Friendship 1912 (T.McP.) Has more resistance than B. 156 (G.L.) Resistant variety (D.F.) Less severely damaged St. Augustine 1917 (C.B.W.), «&c. BADILLA OR NEW GUINEA No. 15. A very stout, dark purple cane with broad dark leaves, wax ring below node distinct. Internode short convex, no channel, bud rather small broad and blunt. The resulting cane is short but very hard and heavy. Difficult to mill except in large mills. Very good root system, few roots above the ground, bulk of roots down to nine inches, manj' roots penetrate below two feet. General growth of roots decidedly downwards. St. Augustine (J.deV.) Introduced from Queensland in 1909, and hence sometimes called " Queensland " cane in Trinidad. Blight. — Have seen badly damaged even as plant canes, does not suit our soil, Carojii (J.G.) Slightly damaged Brechin Castle (J.W.A.) Slightly damaged Waterloo (J.K.) Have not seen damage (D.F., J.J.H., J.R.F., C.A.F.) Generally better than the others (J.B.) Resists froghopper attack better than any other variety. Planting round edge of other varieties to protect, Woodford Lodge (P. de V.) Least severely attacked. St. Augustine 1917 (J. de V.) Damage very slight St. Augustine 1917 (C.B.W.) No visible damage St. Aiigustine 1918 (C.B.W.). Probably the most resistant variety but not generally liked by the factories. UBA. A thin, reed like, yellow^ to yellowdsh green cane with long thin rather pale upright leaves. Internodes parallel sided, relatively long, no channel, bud rather large round pointed. Said to be deep rooted. The cane is very hard with large fibie contents and difficult to mill in small mills. Introduced from South Africa. BlighL^H-axe seen badly damaged (C.A.F.) Have seen badly and slightly damaged but recovers better than any (W.H.B.) Damaged at Harmony Hall m 1917 but much better than B. 347 alongside (C.B.W.) Have not seen damaged (J. J.H., J. R.F.) Have seen slightly damaged (G.H.Hill) Now used on Usine Ste. Madeleine for planting on poor soils where other canes will not grow. Suffers but little from root fungi (C.B.W.) Higher and thicker than B. 6450 of same age alongside, Union Hall 1918 (C.B.W.) Another of the more resistant varieties. Goes down in bad j'ears when nothing survives. Unfortunately not considered good from the factory point of view. 1919.] SUGAB-CANE VABIE TIES d FEOGHOPPEB BLIGHT. 73 SEA^LY'S SEEDLING. Blight. — Badlj' damaged as plants and ratoons Exchangre 1912 (A.B.) ; six acres ratoons badly injured Waterloo 1912 (J.K.) ; slightly damaged as plants Picton 1912 (J.J.H.); slightly damaged as ratoons Union Hall 1912 (A.R.) ; have seen badly damaged, generally worse than others (G.A.Hill); slightly damaged Harmony Hall 1912 (W.H.B.) ; have seen badly damaged (C.A.F., J.B.); resistant to root disease in the Leeward Islands (F.W.) HILL'S SEEDLING No. 1 (Retrench No. 1). A slightly rusty greenish yellow cane, leaves normal, intemode cylindrical, channel very slight or absent, bud rather small flat round, bluntly pointed. Raised by the late Mr. G. H. Hill at Retrench. Brittle and liable to crack between the nodes (C.B.W.) BUght.—B&d\\ damaged 1917 (plants) and 1918 (ratoons) Corinth (C.B.W.) ; young plants damaged by froghoppers f''om field alongside Golconda 1917 (C.B.W.) Have seen badly damaged (W.H.B.) Have seen slightly damaged, generally better than the others (G. H. Hill). Have not seen damaged (J.J.H., .T.R.F., C.A.F.) Standing out better than others in mixed farmers cultivation Inverness 1918 (C.B.W.) HILL'S SEEDLING No. 12 (Retrench No. 12), Large rusty-orange waxy cane, leaves broad, internodes slightly convex, channel absent, bud large round and pointed. Raised by the late Mr. G. H. Hill at Retrench. Blight.— Badly damaged as plants 1917, not damaged as ratoons 1918, Golconda (C.B.W.) No root disease or froghopper on plants, Corinth 1918 (C.B.W.) Have not seen damaged {G. H. Hill). FOSTER'S SEEDLING (FOSTER'S BEAUTY). Reddish green to yellow cane, incliiTed to be thin in ratoons, leaves normal. Internodes 'cvlindrical, furrow distinct to very slight; bud round, rather fat, not Very large, broad, bluntly pointed. Raised by Mr. .J. R. Foster at La Fortunee. Blight.— B-iiQ\]y damaged as plants at Golconda 1917, distinctly damaged as 1st ratoons but recovered 1918, (C.B.W.) Not so good as D. 145 supplies La Fortunee 1919 ('LB.W.) Not so good as as D. 625 supplies Golconda 1919, (0.B.W.1 Have seen badly damaged (C.A.F., J.H. Hill). Have seen slightly damaged (.T.R.F.). WHITE TANNA. A very upright tall stout yellow cane, leaves erect, internodes long and cylindrical, channel very slight or absent, buds round, slightly pointed. Does not bunch much so might stand closer planting. Introduced recently from Mauritius where it originated as a bud-sport of Striped Tanna. Only lately distributed from the St. Augustine Experiment Station. Blight.— SMghtlv damaged but recovered St. Augustine 1917 (C.B.W.) No visible damage St, Augustine 1918 (C.B.W.) LOUISIANA PURPLE. A red cane blotched occasionally with yellow or yellowish green, wax distinct throughout upper internodes. Internodes cylindrical, channel distinct, bud large triangular pointed. Recently introduced at Waterloo. " Arrowd too freely " (A.B.) Has- not so far been damaged by blight. 74 TS IN ID AD AND TOBAGO BULLETIN. [XVIII. 2. COMMON EED OK CONGO RED. A bright red cane sometimes with darker red streaks, internodes cyhndrical, no channel, bud very small round flat pointed. Now very little in cultivation. Occasionally seen among Farmers canes, Not in favour and often only bought by estates at a low price. Blight.— %[\g\ii\y damaged as ratoons, Waterloo 1912 (.T.K.) One of the most resistant varieties (J.B.) WHITE TRANSPARENT. A grey or pinkish cane with broad dark leaves, inclined to trail. Not much in cultivation in Trinidad to-day. Blight.— Vi&AXy damaged as ratoons, Exchange 1912 (A.B.) ; slightly damaged as ratoons Waterloo 1912 (J.K.) Suffers slightly from root disease in Barbados (J.R.B.) Not suitable for heavy lands of British Guiana (J.B.H.) STRIPED EGYPTIAN. A striped red and yellow cane, darker where shaded than on edge of field. Leaves normal, upper nodes waxy. Internodes cyUndrical, channel broad and very distinct. Bud very large and pointed. Ir cultivation at Union Hall in 1917-18. No record of damage. VENEZUELAN BOURBON. A reddish green cane with thick Avax deposit over whole of young internodes. Leaves somewhat broad. Internodes rather short, cylin- drical to slightly convex, channel slight or absent, more distinct in young shoots pf rapid growth. Bud small, round, rather Hat. In cultivation at Union Hall. i?//£77;^— Damaged at Union Hall in 1918 (C.B.W.) ANTIGUA No. 2. A yellow cane, leaves normal to rather dark. Internodes a little short and cylindrical, channel slight or absent, dark ring below node distinct and'waxy. Bud large round pointed. In cultivation at Union Hall and Petit Morne. Blight.— B-S-ye seen slightly damaged (G. H. Hill). Slightly damaged Petit Morne 1917 (C.B.W.) D. 78. Apparently not now in cultivation. Only one record. Blight. — Severely damaged as plants at Brechin Castle in 1906, following year undamaged (J.W.A.) D. 95. Large dark purple, erect cane with long internodes which are channelled. Waxy, eyebuds flat, broad and pointed and very protuberant. A seedling of White Transparent (Caledonian Queen). Blight.— Destroyed at Caroni in 1906 (J.G.) Gave 30 tons per acre 5th ratoons in 1905, compktaly destroyed in 1906 Brechin Castle (J.W-A.) Resistant to root disease in Leeward Islands (F.W.) Badly attacked by root disease in Barbados in 1906 (J.R.B.) 1919. 1 SUGAR-CANE VAEIETIES d FBOGHOPPEB BLIGHT. D. 109. A reddish purple cane with rather dark leaves, the wax ring just below the node distinct. Internodes cylindrical or slightly convex; channel slight to distinct, short ; bud small round and rather tlat. Seedling from " Wliite Transparent.'" In very general cultivation. -BZ/(77i!'.— Badly damaged as plants and ratoons Exchange 1912 (A.B.) Petit Morne 1912 (A.M.M.) Hadly damaged Forres Park 1912 (F.J.M.) Harmony Hall 1912 (W.H.B.) Union Hall 1912 (A.P.) Malgretout 1912 (D.C. A.I.) Friendship 1912 (J. M.) Waterloo 1912 (J.K.) Brechin Castle 1912 (J.W.A.) Caroni 1912 (J.G.) Orange Grove 1917 (C.B.W.) Caroiii 1917 (C.B.W.) Caroni 191S (C.B.W.) Caroni 1008 (J.G.) Badly and slightly damaged but generally picks up quicker than other varieties after an attack (A.B.) Stands attack fairly well but have seen suffer severely (J.G.) Generally better than the others (W.H.B.) A few fields badly damaged at Brechin Castle in 1917 but resists blight fairly well (J.W.A.) Generally better than any other cane I know (G.'J.R.) Generally better than others (G.H. Hill). One of the most resistant, in 1917 the froghopper attack spread across the estate but jumped all the fields of D. 1U9 (H.T.C.) Standing out among B. 347, Reform 1918 (C.B.W.) Standing out among B. 156, Reform 1918 (C.B.W.) Not attacked at Bien Venue and La Forbunee in 1912 even as old ratoons alongside completely destroyed B. 156 (G. H. May), &c., &c. I/ca/ Z) /.seas?.— This variety is particularly liable to a leaf disease which, at the end of the wet season causes the leaves to be marked with elongated brown streaks which may coalesce and cover the whole leaf. Mr. Nowell after a preliminary examination believes the disease to be Helminotlios]}orium, known as " eye spot " disease. Up to the present it has never occurred sufficiently early in the year to cause any serious harm. In a field of mixed D. 109 and B, 156 at Golconda in 1917 every plant of D. 109 was heavily infected while the leaves of the B. 156 were still healthy and green. D. 115. A reddish or greenish orange cane inclined to be blotched with rusty o.r black patches. Stout, leaves erect. Internodes cylindrical, no channel, buds round and flat.' Blight.— Bsidily and shghtly damaged Exchange (A.B.) Have seen slightly damaged fJ.B.). Badly damaged but recovered later St. Augustine 1917 (C.B.W.) No visible damage St. Augustine 1918 (C.B.W.) D. 116. Rather thin yellowish green, erect cane with dark leaves. Internoles cylindrical, channel slight or absent, bud large round and flab. Blight. — Badly damaged as plants and ratoons Caroni 1912 (J.G.) Brechin Castle 1912 (J.W.A.) Exchange 1912 (A.B.) Wat3rloo 1912 (J.B.) Badly damaged Htxrmony Hall 1912 (W.H.B.) St. Augustme 1917 (J. deV.). Badly damaged but recovering St. Augustine 1917 (C.B.W.) Distinctly damaged as plants Brechin Castle 1918 (C.B.W.) Badly damaged Caroni 19J3 (J.G.) Have seen slightly damajed (G.H. riill). 76 TRINIDAD AND TOBAGO BULLETIN. [XVIIL ^. D. 145. Thick heavy dark red or purple cane. Recumbent. Internodes cylindrical. Buds large, prominent and rounded. Seedling from " Red Ribbon." Blight. — Badly damaged as plants and ratoons Caroni 1912 (J.G.) Given up, it suffers too much (J.G.) Badly damaged as ratoons Exchange 1912 (A.B.) Badly damaged Harmony Hall 1912 (W.H.B.) St. Joseph 1917 (J. de V.) Slightly damaged as plants and ratoons Waterloo 1912 (J.K.) Not so liable to root disease in Demerara (C.K.B.) Generally better than others (J.B.) Badly damaged by root disease in farmers "^ canes Reform 1918 (C.B.W.) Standing out better among Fosters Seedling La Fortunee 1919 (C.B.AV.) No visible damage St. Augustine 1918 (C.B.W.) D. 366. A rather naiTOw, yellow cane with narrow erect leaves. Internodes cylindrical, channel long and distinct. Bud narrow small and pointed. ' Poor root system, bulk of roots down to six inches, few below 18 inches, tend to spread laterally, St. Augustine 1917 ' (J. de V.) Blight.— Yery badly damaged St. Augustine 1917 ; worse than D. 504 and B. 156 on either side (C.B.W.) Given it up, suffers too much (J.G.) Root disease severe St. Augustine 1917 (J. deV.) D. 504. A large dark red cane with short internodes, leaves dark broad and short. Internodes slightly convex, wax ring below node distinct, na channel. Bud very small round and fat. Cane slightly zig-zag in growth. A seedling of D. 145. Blight. — Badlv damaged St. Augustine 1917 (J. de V.) Recovered a little later (C.B.W.) No visible damage St. Augustine 1918 (C.B.W.) D. 625. A very large and vigorous cane, clear yellow with occasional reddish blotches. Internodes cylindrical, no channel. Bud small round flat pointed. One of the largest and most striking canes in cultivation but not in general favour at the factoi-ies m Trinidad owing to its poor juice. In Demerara on the other hand it composed nearly 50 per cent, of the cane crop in 1917, when 36,000 acres were grown. Blight.- 'BsidXy damaged Harmony Hall 1912 (W.H.B.) Badly damaged as plants Petit Morne 1912 (A.M.M.) Badly damaged as plants and ratoons Picton 1912 (J.J.H.) 15 acres badly damaged as plants Bien Venue (G. H. Hay). Badly damaged as plants and ratoons Malgretout 1912 (D. C.A.I.) Badly damaged as ratoons Exchange 1912 (A.B.) Badly and slightly damaged plants and ratoons Brechin Castle 1912 (J. A.) Badly damaged ratoons, slightly damaged plants Caroni 1912 (J.G.) Badly and slightly damaged plants Woodford Lodge 1912 (P. de V.) Ten acres slightly damaged as ratoons Williamsville 1912 (M.M.) Generally better than the others (J.B.) Have seen slightly damaged, generally better than others (G. H. Hill). Standing up among damaged " Fosters Seedling " Golconda 1919 (C.B.W.) Liable to root disease in Demerara (C.K.B.) 1919.\ SUGAR-CANE VARIETIES d- FEOGHOPPEB BLIGHT. 77 D. 790. Only one record. Blight. — Nineteen acres of plants slightl}' attacked at Caroni in 1912 (J.G.) D. 1082. Onlj' one record. Blight. — Thirtv-one acres of plants badly damaged at Caroni 1912 (J.G.) D. 216S. Stout dark red-brown to yellowish-brown rnsty cane. Very waxy. Leaves broad, stem slightly zig-zag. Intemodes cylindrical waxy throughout, slight furrow. Bud rather large broad fiat blunt. ' Fair root system, bulk of roots down to six inches, few roots penetrate below 17 inches; roots tend to spread laterally' ; large number of secondary roots on surface roots St. Augustine 1917 ' (J. de V.) Bliglit. —\ery severe, badly damaged St. Augustine 1917 (J.deV.) Root disease fairly bad St. Augustine i917 (C.B.W.) Always gets root disease (L.B.) Twelve acres of plants badly damaged, Caroni 1912 (J.G.) Slightly damaged at Brechin Castle (J. A.) No visible damage St. Augustine 1918 (C.B.W.) Leaf Disease. — Much eye spot {Leptosphoiria) between D. 50-1 and D. 145 both almost free St. Augustine 1919 (C.B.W.) D. 3956. A somev\hat stout, yellow cane. Leaves rather broad and erect, Intemodes cylindrical or sHghtly convex, channel slight or absent. Bui not large, round, slightl}' pointed. Blight.— •SYighily damaged at Brechin Castle (J.W.A.) Slio-ht root fungus St. Augustine 1918 (C.B.W,) Leaf Diseasc.— Tlhisi variety during 1917 and ]918 suffered at St. Augustine from an unknown disease causing a mottling of the leaves with pale semi-translucent yellowish green spots. The varieties D. 366 and I). 145 on either side were practically free from this condition (C.B.W.) D. 4397. Closely resembles Bourlo i. Seedling from Bourbon, raiie 1 in 1897. 5/z>//i.— Slightly damaged (T.W.A.) B idly damagid as plants at Caroni 1912 (J.G.) & i i. D. 4805. Thin yellow cane wilh red patches, upright. LiteraoJes cvlindrical. Buds small, rounded and pro.ninent. Only one recorl. £^■r//(^'. --Seventeen acres of plants damaged at Caroni in 1912 (J.G.) 78 TEINIDAD AND TOBAGO BULLETIN. [ XVIII. 2, T. U6. Raised from seed D. 116 in 1897 b}- J. H. Hart. Apparently na longer in cultivation. Blight. — 10 acres badly damaged as ratoons Friendship 1912 (J.M.) Badly damaged as ratoons Exchange 1912 (A.B.) Slightly damaged as- ratoons Waterloo 1912 (J.K.) Generally worie than others (J.B.) T. 247. Raised from seed by J. H. Hart. Apparently no longer in cultivation. Blirjht. — Badly damaged as ratoons Caroni 1912 (J.G.) Slightly damaged as ratoons Exchange 1912 (A.B.) Waterloo 1912 (J.K.) Have seen damaged (W.H.B.) Generally -worse than the others (-l.B.) B. 147. A fairly upright yellow cane mottled with red. Leaves normal or rather dark. Internodes cylindrical, furrow distinct o,nd long. Bud round and pointed not small. Blight. — Badly damaged as ratoons Exchange 1912 (A.B.) Slightly damaged as plants and ratoons Waterloo 1912 (-i.K.) Slightly damaged as plants Union Hall 1912 (A.R.) Suffers very much at Caroni (J.G.) Slightly damaged at Brechin Castle (J.W.A.) Generally better tliau others (J.Ji.) Have seen slightly damaged, generally better than the others (G.H.Hill). Have not seen damaged (C.A.F.), (J.J.H.) Said to be i-esistant to root disease in the Leeward Islands (F.W.) Plants badly attacked by root disease in Barbados 1906 (J.R.B.) B. 156. A yellow cane, leaves rather pale. Internodes cylindrical, no channel, buds round and blunt. The most generally cultivated cane in Trinidad ; known to small farmers as " Seedlings " " Little Roseau " and " Esperanza." Blight. — Particularly prone to froghopper attack. Suffers more than any other variety but recovers more rapidly ( I'.deV.) One of the very worse in a bad attack but if not too badly damaged recovers quickly (J.G.) This cane is the worst I know (G.C.R.) Badly damaged Harmony Hall 1912 (W.H.B.) 90 acres badly damaged and 175 slightlv damaged T'nion Hill 1912 (A. 11.) Badly damaged as plants and ratoons Petit Morne 1912 (A.M.M) Picton 1912 (J.J.H.) Plein Palais 1912 (A.D.L.) Esperanza 1912 (C.C.) Waterloo 19P2 (J.K.) Exchange 1912 (A.B) Woodford Lodge 1912 (P. de V.) Brechm Castle 1912 (J.W.A.) Caroni 1912 (J.G.) Badly damaged Hermitage 1917 (C.B.W.) La Fortunee 1917, 1918 (C.B.W.) Wellington 1917. 1918 (C.B.W.) Williamsville 1918 (C.B.W.) Not so good as D. 109 supplies Reform 1918 (C.B.W.) Better than " Fosters Seedling;' alongside La Fortunee 1919 (C.B.W.), &c., &c., &c. B. 208. A rusty yellowish green cane, generally covered with wax. Leaves rather large and broad. In';e nod:s slightly bulging, no channel. Bud small, rcuud and pointed. 1919.} S VGAR-CANE VABIE TIES d FBOGHOPPEE BLIGHT. 79 Blight. — Badh- damaged Forres Park (D.F.) Have seen badly damaged (W.H.B.), (J.B.) Badly damaged ratoons Caroni 1912, given up (J.G. Slightly damaged as ratoons "Waterloo 1912 (J.K.j Badly damaged Forres Park 1911 (F.J.M.) Better than others (H.T.C.) Have not seen damaged (J.J.H.), (C.A.F.) B. 306. Yellow cane not unlike Bourbon. Now out of cultivation. Blight. — Have seen badly damaged (G.H. Hill), (C.A.F.) (J.B.) Badly damaged as ratoons Petit Morne 1912 (A.M.M.) Slightly damaged as ratoons Waterloo 1912 (J.K.) Exchange 1912 (A.B.) Badly damaged as ratoons Caroni 1908, 1912 ; given up (.J.G.) B. 347. A rusty yellow cane. Leaves rather dark and erect. Stem slightly zig-zag. Internodes conve-x, channel slight or absent, bad small and round. Known to farmers as " Burks." Blight.— B&d\y damaged Forres Park 1912 (F..J.M.). Union Hall 1912 (A. R.) Badly damaged plants and ratoons Picton 1912 (J.-J H.), Exchange 1912 (A.B.) Brechin Castle 1912 (.J.W.A.) Caroni 1912 (J.G.) Completely destroyed between beds of " Uba " not so bad Harmony Hall"l917'(C.B.W)) Badly damaged as plants Brechin Castle 1913, then four gooJ ratoons from same field (J.W.A.) Badly damaged Hermitage 1917 (C.B.W.), Union Hall 1918 (G.B.W.) Very badly damaged as plants and first ratoons Caroni 1908 (J.G.) Not so good as D. 109 planted alongside. Reform 1918 (C.B.W.) Root disease bad in old ratoons Hindustan 1918 (C.B.W.) Root disease in farmers canes Keform 1918 (C.B.W.), &c., &c., &c. B. 376. Reddish green waxy cane with broad leaves rather light in colour. Internodes cylindrical, channel slight or absent. Bud small flat and blunt. Blight. — Badly damaged as plants and ratoons Exchange 1912 (A.B.) Badly damaged as ratoons Petit Morne 1912 (A.M.M.) Badly and slightly damaged as ratoons Brechin Castle 1912 (J.W.A.) Have seen badly damaged (G.H. Hill), (W.H.B.) Least resistant variety (D.F.) Least severely attacked St. Augustine 1917 (J. de V.) Given up, suffers badly (J.G.) B. 1753. A rather narrow yellow cane with light green erect leaves. Inter- nodes cylindrical, channel slight or absent, bud small round and flat. '■ Had to give up in St. Kitts because shallow rooted and too easily pulled out by hurricanes (C.F.T.) " Fairly good root system, few roots above ground bulk of roots down to seven inches, large number of roots penetrating below two feet, roots tend to grow downward St. Augustine (J. de V.) Blight, — Plants badly damaged, Brechin Castle 1912, one of the least resistant varieties (J.W.A.) Badly damaged Tarouba 1918 (C.B.W.) Damage distinct St. Augustine 1917 (C.B.W.) Given up suffers badly (J.G.) Have not seen damaged (J.J.H.), (C.A.F,) 80 TBINIDAD AND TOBAGO BULLETIN. [XVIIL 2. Leaf Disease. — Leaves flecked with semi-transparent pale yellow spots St. Augustine December, 1918 (C.B.W.) B. 3390. A yellow upright cane. Leaves erect. laternodes long and cylindri- cal, channel slight or distinct. Buds small flat pointed. Blight.— Ba,d\y damaged St. Augustine 1917 (C.B.W.) Slightly damaged as ratoons Exchange 1912 (A.B.), Waterloo 1912 (J.K.) Have seen badly damaged (C.A.F.) B. 3405. Greenish yellow cane, upright, buds prominent and easily broken off. No longer in cultivation Blight— Badly damaged as plants and ratoons Exchange 1912 (A.B.) Slightly damaged as plants and ratoons Waterloo 1912 (J.K.) B. 3412. A yellowish green cane. Leaves normal. Internodes cylindrical, rather long. Distinct wax ring below node, no channel. Bud flat rounded. " Fairly good root system, very few roots above the ground, bulk of roots down to six inches ; very few below eighteen inches, roots tend to grow downward, St. Augustine (J. de V.) i?%7iif.— Badly damaged as ratoons Exchange 1912 (A.B) Slightly damaged as ratoons Waterloo 1912 (.T.K.I Damage distinct, St. Augustine 1917 (C.B.W.) llullv damaged Orange Grove 1917 (C.B.W.) Have seen badly damaged (W.H. 13.) Have seen slightly damaged (C.A.F.) B. 8922. A tall rather erect yellow cane ; leaves upright not broad. Internodes cylindrical, no channel. Bud round, slightly pointed ; base of leaves with irritating hairs. Blight.— Badly damaged at Forres Park (D.F.) No visible dunxge St. Augustine 19 is (C.B.W.) B. 6308. A yellow cane, leaves rather narrow. latjrio.les cylindrical, na channel. Buds small and rounded. " Fair root system, a good many roots above ground, bulk of roots down to eight inches, very few roots below two feet, roots tend genercUly to spread laterally, St. Augustine ( J. de V.) iJZiV//(^ - Slightly damaged Brechin Caitie (J.W.A.) Not dimaged Forres" Park (D.F.^ Distinctly damaged St. Augustine 1917 (C.IJ.W.) No visible damage St. AugusLino 191b (C.Ij.W.) B. 6450. A yellow cane with dark leives. Internodes slightly convex, channel slight or absent. Bud large and pjintad. 1919.] SUGAR-CANE VAEIETIES d- FBOGHOPFEB BLIGHT. 81 5%/;!'.— Damaged Orange Grove 1917 and 1918 (C.U.W.) Badly damaged Caroni 1918 (C.B.W.) Alongside "Uba" and not so good Union Hall 1918 (C.B.W.) Badly damaged (J.B.), (.J.K.), (A.B.), (J.W.A.), (C.A.F.), (W.A.B.), (G. H. Hill.) Suffers less than B. 156 and B. 347 but still far from immune (P. de V.) Does faii'ly well at Caroni but when attacked is slow in recovery (.J.G.) Badly damaged, least resistant variety (D.F.) B. H. 10 (12). A dark rusty brown cane with much wax, leaf normal or rather dark. Stem distinctly zig-zag. Internodes convex, no channel. Bud rather small round and flat. Cultivation at present small but spreading. No records of damage. Ba. 6032. A yellow or slightly reddish yellow cane, of upright growth. Leaves long and erect. Stem distinctly zig-zag. Internodes bulging, no channel. Buds rather large flat and pointed. Pit'centl}' introduced and spreading rapidly. Blight. — No damage at Hermitage (H.T.O.) No damage at Brechin Castle (J.W.A.) No damage at Oaroai (J.G.) No damage at St. Augustine 1917 and 1918 (C'.B.Y,".) The following additional varieties are at present in cultivation at St. Augustine, but are either not found in estates or farmers cultivation, or have been so recently distributed that no records are available of damage : — L. 218 (1) B. 4578 B. 4934 L. 511 H. 27 B. 6388 B. 6335 L. 253 H. 146 B. 7169 B. 74S2 M.P. 55 H. 227 B. 8800 B. 8880 M.P. 87 . .. B. 10850 B. 14761 M. 90a^ . .. B. 16533 B. 16832 M. 1237 . .. B. 17380 T. 39 M. 1479 . ., T. 75 ■ T. 202 CONCLUSIONS. The conclusions that can be drawn from a study of the above evidence are not encouraging to any planter seeking a variety of sugar-cane that is immune from disease. In fact ifc will be found that every variety that has been in cultivation for any length of time has been severely damaged by the '• Froghopper Blight" in some year and in some soils. (1.) H ? A Hawaiian cane of which tlie nunibor on the label was not decipherable ■when the original introduction was made. — (W.G.F.) 82 T BIN ID AD AND TOBAGO BULLETIN. [XVIIL 2. There is no Immune Variety. — It then becomes a question as to relative powers of resistance. Do some varieties, even if damaged, suffer less severely than others under similar conditions '? To this the answer is more hopeful. In collecting evidence for this branch of the problem it is not enough that fields of two varieties side by side should show a different extent of damage. The canes may be of different age, the fields may have had different treatment, the soil, which, in the Naparimas especially, changes rapidly, may be different in two adjacent fields, or even in two parts of the same field. Allowing for such conditions there is still distinct evidence tliat some canes will survive when others are more severely damaged. This difference is usually most strikingly seen in fields of one variety which have been supplied with canes of a second variety. Several examples of this will be found in the above notes. Thus Hill's Seedling No. 1 was standing out among other canes on a Farmers plot at Inverness ; Fostei-'s seedling is not so good as D. 145 or D. 625 supplies at La Fortunee and Golconda respectively. D. 109 is twice recorded as better than B. 156 and again as better than B. 347 ; D. [366 is more severely damaged than either D. 504 or B. 156 on adjacent beds at St. Augustine, etc. Perha25s the most striking example of relative resistance to blight was seen at Harmony Hall in 1917 where a field had been planted with alternate beds of Uba and ]J. 347. The field was heavily infested with Froghoppers, with the result that while the Uba was damaged sufficiently badly to reduce the crop nearly 50 per cent., the B. 347 almost ceased to exist and the end of the field had the appearance of a castellated wall. It must be remembered that these relative differences apply probably only to the particular soil and climatic conditions under which the observations were made. On other soils and with different rainfall the difference might be reduced or even inverted. From a careful inspection of the above results and fi*om personal experience in the field, it is probable that the two most I'esistant varieties at present in cultivation are Bculilla a)id Uba. Unfortunately neither of these canes are in particular favour in the factories, as both are very hard with large fibre contents and except in heavy mills do not give good juice yields. In addition neither are suitable for very heavy soils. Uba cane is being increasingly used by the estates of the Usine St. Madeleine, to grow on small patches of poor soil, along ridges and elsewhere. ^Yhere other canes do not floui-ish, and under such conditions it has been found to give extremely satisfactory results. At the Experiment Station St. Augustine, and on some other estates, are to be found a number of recently introduced varieties. Blight does 1919.\ SUGAR-CANE VARIETIES d FROGEOPFER BLIGHT. 83 not seem to trouble the Experiment Plots at St. Augustine to any great extent so that relative resistance cannot be well studied here, but so far as observations have been made the following recently intro- duced canes seem worthy of more extended trial. Ba. 6032, B.H. 10 (12), White Tanna, H. ? To summarise, no variety of cane at present grown in Trinidad is immune to " Blight." Uba and Badilla are more resistant than the rest and a few recent introductions are worthy of more extended trial. As evidence shows that there is considerable variation in resistance particu- lar attention should be paid to this in the future with respect to new varieties imported, and particularly in connection with the present work of the Department of Agriculture in raising new varieties from i?eed in Trinidad. March, 1919. 84 TRINIDAD AND TOBAGO BULLETIN. [XVIIL 2. PLANT DISEASES AND PESTS, CONTROL OF THE CACAO THRIPS IN TRINIDAD AND TOBAGO. By F. W. Ukich, Entomologist, Board of Agriculture. {With 16 Figures). The following popular account of the Cacao thrips {Selenothrips ruhrocinctus) and methods of controlling it are intended principally for the use of the small proprietors and drivers on estates : — WHAT AKE THRIPS? Thrips are very small insects which belong to the order called Thysanoptera. When young they have no wings but crawl around on the plants on which they live. Tiiey have a habit of carrying their excrement in a small drop at tlie end of their bodies. In the full grown stage they have wings and can tly from tree to tree and even farther especially when helped by the wind. In the adult and young stages tlu'ips live by sucking the sap from the leaves of their food plants. rig. 1. Fig. 1.— Adult female thrips, drawing by Mr. C. IJ. Williams. Greatly enlarged with her wings e.xpandec The natural size it about 1-24 of an inch in length of body, ('olour jet black. 1919.-] CONTROL OF THE CACAO THBIPS. SUMMARY OF LIFE HISTORY. 8S Eggs are laid by the female (fig. 1) in the tissues of young leaves ,' they hatch in about 3 to 4 days. In the case of cacao the female lays also in the skhi of pods that are nearly mature. The young larvffi (fig. 2) take about 9 days to complete their growth and then turn into prepupa? (fig. 3), this stage lasts 24 hours and is followed by the pupal stage (fig. 4) which is completed in 4S hours when adults appear. Fig. 2. Fig.3. Pg. 4-. Fig. 2.— Larval or young stage of thrijjs. The natural size i.s about the same as the adult insect when the larva is full grown. Greatly en- larged. Colour light yellow, dark bands shown on draw- ing are red. Kedrawn from Russell. Fig. 3.— Piepupalstago. Greatly enlaiged. Colour and size more or less like larva with red bands. Ke- drawn from Paissell. Fig. 4. — Pupal stage- Greatly enlarged. Colour and size more or less like larva with red bands. Ke- drawn from Russell. The total period of development amounts to 12 days from the hatching of the egg to the appearance of perfect insects. The female lays- eggs without pairing for several generations and males are not common, occurring only at certain seasons and then not in large numbers. The number of eggs a female can lay is estimated at about 50. The length of the life of a female has not been determined 86 TEINIDAD AND TOBAGO BULLETIN. \XVIIL 2, but it may occupy several weeks. Belated species of thrips have been known to live from 34 to 84 days in captivity. Generation is continuous and every 20 daj's there can be a new brood. At this rate the increase of thrips is very large and quick and the progeny of a single female might reach a million in a couple of months. See figm-es 1-4. FOOD PLANTS. The cacao thrips is also found on the following plants : hog plum, mango, guava, avocado, ahiiond {Tcrminalia catajypa), mammy apple, cashew, roses, pois doux and pomme rose. All these plants are restricted to certain seasons for the putting out of new leaves and thus form continuous favourable breeding grounds for thrips during the whole year. There are many other thrips to be found on the cacao and other plants mentioned, but most of these do no harm. The cacao thrips does not occur in flowers ; the black thrips so often found in the flowers of the Bois Immortel and even cacao are different species and are not injurious. SEASONAL HISTORY OF THRIPS. As with many other insects the increase of thrips depends on the abundance of its food plants and on the condition of the leaves that are best suited to it. From continued observations since 1909 I And that thrips in all stages prefer the young leaves of their food plants although they can exist on fully mature leaves. Different kinds of trees put out young leaves at different times but a great many, and among these the cacao trees, put out their new shoots and leaves during the rainy season. It is then that the thrips commence their multiplication on cacao. Previous to that and during the dry season thrips will exist on such food plants as put out new leaves then, for example mangos and almonds ; or they will attack stray cacao pods or such stray cacao suckers as exist. As far as cacao is concerned we can say that the thrips season begins with the rainy season and that the maximum multiplication takes place just after the heavy rains of May, June and July ; roughly speaking it may be stated that thrips begin with the setting of the cacao crop. All the time the leaves are young and not too tough and the rains are still on, thrips remain at the tops of the trees, but when the weather becomes drier they descend to the shaded pods and suckers and can be found on these right through the dry season. A certain degree of moisture appears to be necessary for the well being of tln-ips. At the height of the dry season they are at their lowest ebb but still never disappear entirely, and if cacao does not offer suitable food they will migrate to other host plants that happen to be in tender foliage at that time. In this connection mangos, almonds, hog plums, and cashew should be watched. During sjiells of dry weather damage from thrips becomes more apparent, but extensive multiplication and feeding take place during damp weather. In the following table an attempt is made to show the seasonal history of thrips and the food plants on which they are likely to be found. The rainy and dry seasons can only be taken as approximate. 1919.] CONTROL OF THE CACAO THBIPS. b7 TABLE ILLUSrEATING SEASONAL HISTORY OF THRIPS. Month. Season. May June July August September. . October .. November.. December... January . . Rainy February ... ,, Dr March April Very dry Foo 1 Plants and parts of them affected. Remarks. Wao, liavts oi lops of trees. also Cacao pods and on leaves of suckers. Heavy rains, thrips not numerous. Thrips active and laj'- ing eggs vhen laiiis abate. Young stages and adults numerous. Leaves of cacao dropping, ■when severely attacked, thiips living on pods and suckers. also mango & almond leaver. Mangos, hog p 1 u m, IThrips decreasing on cashew, guava and roses cacao on leaves. Few thrips in any stage on cacao. WHAT BECOME OF THRIPS IN THE DRY SEASON? Thrips do not disappear altogether during the dry season. The numbers are greatly reduced owing to the want of moisture but they always manage to e.xist in damp plao 's and on other plants than cacao. The females are not very active iji laying eggs during the dry season and most of the thrips pass through this season in the adult stage. It is not possible for eggs to remain dormant in dry leaves on the ground, j HOW DO THRIPS DAMAGE CACAO? Thrips damage cacao principally by feeding on the sap of the leaves, and when the attack is severe, drying them so much that they appear as if scorched by fire and then drop from the tree. The pods are also ■damaged, but in this case loss results chiefly owing to discoloration of the skin making it difficult to know whether a pod is ripe or not. When a great many leaves are damaged and have dropped from the trees, the young and half -ripe pods will wither and in this manner the tree will- lose its crop and have a sst back. See figure 5. 88 TRINIDAD AND TOBAGO BULLETIN. [XVITI. 2^ Rci.5i Fig. 5. — Cacao leaf afe t.d liy t'a.ips about natural s'ze showing (n) excrement spots, (?<) feeding iiiai-ks which a: e hro-AU a 111 (c) egg spots which aie dark brown and generally near the veins of the leaf. Original drawing. OX WHAT PARTS OF THE CA.CAO TEEES ARE THEirS FOUND? Thrips are found generally on the underside ( f tlie leaves. Luring the damp s-easo.i they ar3 to be seen on leaves on the lop of trees, but as the season gets dry, Ihey go down nearer the ground, and are then found on the suckeis and i oJs. Somet'mcs adults aid young stages crawl on tl;e upper surfac3 of leaver but do not reniahi there long. 1919.\ CONTROL OF THE CACAO THRIPS. 89 HOAV CAN THRIPS BE DESTROYED? Tlirips can be destroyed by means of spraying with a suitable liquid applied at the right time of the year. When on the pods, they can also be killed by painting the pods with a suitable liquid. When ripe pods are picked with a great many thrips on them the shells should be buried or covered with earth and not left exposed. When suckers or chupons are infested they should be cut out and burnt. WHEN SHOULD THRIPS BE SPRAYED? Thrips should be sprayed after the heavy rains of June, July and August, but it is very difficult to make hard and fast rules. It is most important that the first broods be destroyed as soon as they appear after the rains. A good time to spray is just after the crop has set properly after the heavy rains. When possible, three sprayings should be given with a month's interval between each. MANNER OF SPRAYING. One of the essential conditions to observe in spraying for thrips is that it must be thoroughly done and a good pressure used. Plenty of liquid should be used, as the whole tree and fruit must be sprayed, taking care that the underside of the leaves is thoroughly wetted. It is necessary that in applying the Hquid the nozzle be held close to the leaves of the tree. SPRAYING OUTFIT. Any good make of hand pump capable of giving and maintaining good pressure is suitable for spraying cacao thrips. The following are recommended. For Small Estates. 1 Small hand pump of the type of fig. 6. 1 Bamboo rod 10-12 ft. long (fig. 8). 1 Stop cosk for rod (fig- «)■ 1 Angle nozzla with hole j^^g- of an inch in diameter (fig. 9). 1 Length hose -j ir.c'i bora 2.j-."0 feet in len;;th. ct< -/~Ot rig. 6. Fig. 0." Small barrel pump (") ajitator, {b} plunger tube, (c) delivery t'lbe, (d) air chamber. Ongiual drawing. 90 TBINIDAD AND TOBAGO BULLETIN. [XVIII. S. The pump may be mounted on a drum or barrel as shown at fi". 7. Fig. 7. — SinaH hand pump mounted on 10 gallon iron drum, showing complete outfit in use. Original drawing. I I ,,^ j ^.„ | p,.-.,.„„^n..„ c ^ < K 1-? < te so a S-i > < Jerrahan Creole Variant 2 H. 6 A.H.C. 38 10 19-0 136-31 24-55 61-92 109-05 38 11 21-9 84-82 2392' 50-44 67-86 37 8 20-0 147-33 9-40 47-17 113-86 45 13 24-3 10899 25-73 55-39 87-19 49-54 40-35 37-74 From the above it will be seen that the average yield per acre for the 50 selected plants is not much higher than that usually obtained from good varieties in a favourable season, but the yield from the best single plant may be three times as high as that of the average yield of the selected plants. In 1918, the seed from the best plant of the previous year was planted in a separate nursery and 200 of the strongest plants were planted singly one foot apart. When these were ripe, 50 of the best plants were again reaped separately, the numbers of tillers counted and the seed weighed with the following results : — Second Year's Selection 1918- -50 Pl ants. Number of Tillers per Plant. Weight of Seed per Plant in Grammes. Paddy per Acre Brls. OF 120 lb. Varietv. . i "Sb 1 CO is Average Highest. Lowest. to > < CO so s-< > < Jerrahan 46 20 30 4 99-8 40-32 62-90 79-66 50-32 Creole Variant 2 89 16 54-5 173-26 36-05 104-45 138-61 83-56 H. 6 .., 26 12 19-2 77-46 32-07 53-04 61-97 42-43 A.H.C. . . 57 17 36-8 135-56 .38-19 84-63 108-45 67-70 If the results of the second year's selection are compared with those of the first year it will be seen that not only has a larger average numbers of tillers per plant been obtained but also a larger yield from the best plant and from the average of the 50 selected plants. It is hoped that by continuing this selection of the best plant yearly a strain or strains of rice may be obtained which will give much larger crops of paddy than is now obtained. Short Title. Interpreta- tion. Agreements to pay wages otherwise than in money illegal. Agreements as to place, maimer, etc. of spending wages illegal. 104 TBIA'IDAD AND TOBAGO BULLETIN. \XVIIL 2. AGEICULTUBAL LEGISLATION. TRUCK ORDINANCE 1918. TRINIDAD AND TOBAGO. No. 34.-1918. LL.S.] I ASSE^'T, J. E. CHANCELLOR, Governor, 20th December, 1918. AN ORDINANCE to prohibit the payment of wages otherwise than in money. [By Proclamation.] Be it enacted by the Governor of Trhiidad and Tobago with the advice and consent of the Legislative Council thereof as follows : — 1. This Ordinance may be cited as the Truck Ordinance, 1918. 2. In this Ordinance unless the context otherwise requires: " Employer " includes any master, manager, foreman, clerk or other person engaged in the hiring, employment or superin- tendence of the service work or labour of any labourer within the meaning of this Ordinance ; " Labourer " means any person employed for wages in work of any kind, and whether under or above the age of 21 years, but does not include domestic servants. " Money " means coin of the realm current in the Colony, and includes Government Currency notes and the notes of any banking corporation carrying on business in the Colony ; 3. In every agreement or contract for the hiring of any labourer or for the performance by any such labourer of anj' work within the Colony, except as otherwise provided in this Ordinance, the wages of such labourer shall be made payable in money and not otherwise, and if in any such agreement or contract the whole or any part of such wages shall be made payable in any other manner, such agreement or contract shall be illegal, null and void. 4. No employer shall directly or indirectly by himself or his agent, impose as a condition, express or implied, in any agreement or contract for the employment of any labourer any terms as to the place or the manner in which, or the person with whom, any wage or portion of wages paid to the labourer are or is to be expended, and every agree- ment or contract between an einployer and a labourer wherein any such terms are expressed or implied shall be illegal, null and void. 1919. TRUCK ORDINANCE. 105 5. Except where otherwise permitted by the provisions of this Ordinance, the entire amount of the wages earned by or payable to any labourer in respect of any work done by him shall be actually paid to him in money, and every payment of or on account of any such wages made in any other form shall be illegal, null and void. 6. Nothing in this Ordinance contained shall render illegal an agreement or contract with a labourer for giving to him food, a dwelling place or other allowances or privileges in addition to money wages as a remuneration for his services. 7. Nothing in this Ordinance contained shall be held to apply to any body of persons working on an agreement of co-operation. 8. Every labourer shall be entitled to recover in an action so much of his wages exclusive of sum? lawfully deducted in accordance with the provisions of this Ordinance as shall not have been paid to him in money. 9. Nothing in this Ordinance contained shall extend or be constraed to extend to prevent any employer of any labourer or agent of such employer from making any stoppage or deduction from the wages of such labourer for or in respect of any tools and implements to be used by such labourer in his occupation as such, or for land rent then due and payable. 10. Nothing in this Ordinance contained shall be construed so as to render illegal daductions from wages of fines incurrad by labDurers under any contract or regulations governing their employmanb or in respect of negligent work or injury to materials. 11. Whenever any advance of money or of any of the articles specified in Section 9 hereof is made by an employer to a labourer it shall not be lawful for the employer to make any deduction in respect of such advance on account of poundage, discount, interest, commission or any similar charge. 12. Nothing in this Ordinance contained shall be held to apply to any immigra.nt under indenture. 13. If any employer or his agent contravenes any of the foregoing provisions of this Ordinance, such employer or agent, as the case may be, shall be guilty of an offence against this Ordinance, and shall be liable on summary conviction to a penalty not exceeding £5 for the first ofi'ence, to a penalty not exceeding £10 for the second offence, and in case of a third offence such employer or agent shall be deemed guilty of a misdemeanour and on conviction thereof shall be punishable by a fine not exceeding £'50. 14. All offences under this Ordinance punishable on summary conviction shall be prosecuted before a Magistrate in the manner set forth in the Summary Conviction Offences (Procedure) Ordinance, 1918. 15. This Ordinance shall commence on a day to be fixed by the Governor by proclamation in the Royal Gazette. Passed in Council this Twenty-ninth day of November, iu the year of Our Lord one thousand nine hundred an.l eighteen. "Wages to be paid entirely in money. Remunera- tion other than wa?es. Persons work- ing in co-operation. Labourer's right to recover. Deductions from wages. Fines for negligence or injury. Interest, discount, etc.,. forbidden. Indentured Immigrants. Penalties. Procedure^ Commence- ment. J. M. FARFAN, Acting Clerk of the Council. 106 TBINIDAD AND TOBAGO BULLETIN. \XVIII. 2. LABOUR EXCHANGES ORDINANCE. TRINIDAD AND TOBAGO. Short Title. Interpreta- tion. Establishment ■ of Labour Exchanges Regulations. Penalty for making false statements, etc [L.S.] No. 13.-1919. I ASSENT, W. M. GORDON, Acting Governor. 2nd June, 1919. AN ORDINANCE to provide for the establishment of labour exchanges. \2nd June, 1919.'] Be it enacted by the Governor of Trinidad and Tobago with the advice and consent of the Legislative Council thereof as follows : — 1. This Ordinance mav be cited as the Labour Exchanges Ordinance, 1919. 2. In this Ordinance " labour exchange " means any office or place used for the purposes of collecting and furnishing information, either by the keeping of registers or otherwise, respecting employers who desire to engage workmen and workmen who seek engagement or employment. 3. The Governor may establish and maintain labour exchanges in such places as he thinks fit, and may appoint managers thereof and such other officers as he may think fit, at such salaries as he with the consent of the Legislative Council may from time to time fix. 4. The Governor may make regulations with respect to the manage- ment of labour exchanges established under this Ordinance, and such regulations may authorise advances to be made by way of loan towards meeting the expenses of workmen travelling to places where employment has been found for them through a labour exchange. Such regulations shall be laid before and be subject to the approval of the Legislative Council, and shall when so approved be published in the Boyal Gazette. 5. If any person knowingly makes any false statement or false representation to any officer of a labour exchange established under this Ordinance, or to any person acting for or for the purposes of any such labour exchange, for the purpose of obtaining employment or procuring workmen, or for the purpose of preventing any employer from obtaining workmen, or any workman from obtaining employment, that person shall be liable in respect of each offence on summary conviction to a fine not exceeding .£10. Passed in Council this Sixteenth day of May, in the year of Our Lord one thousand nine hundred and nineteen. J. M. FARFAN, Acting Clerh of the Coicncil 1919.] 107 HABITUAL IDLERS ORDINANCE. TEINIDAD AND TOBAGO. No. 7.- [L.S.1 -1918. I ASSENT, J. R. CHANCELLOR, Governor. 27th April, 1918. AN ORDINANCE to provide for the disciphne and reformation of habitual idlers. [By Proclamation.] Be it enacted by the Governor of Trinidad and Tobago with the advice and consent of the Legislative Council thereof as follows : — 1. This Ordinance may be cited as the Habitual Idlers' Ordinance, 1918. '2. In this Ordinance, unless the context otherwise requires : ■ "Habitual idler" means any male person who has no visible lawful means of subsistence and who, being able to labour, habitually abstains from work. 'Habitually abstairs from work," and cognate expressions, as applied in this Ordinance to any person, means that such person, during the 7 days immediately preceding the laying of a complaint against him, or his arrest, under this Ordinance, has not worked for a period of 4 hours during each of 3 such days or for a period of 14 hours during such period of 7 days ; " Constable " means a member of the Constabulary Force. 3. A constable may sue out a summons from a Magistrate or Justice calling upon any person whom he has reasonable cause to suspect of being a habitual idler to appear before a Magistrate to answer why he should not be dealt with as a habitual idler. 4. A constable may demand the name and address of any person whom he has reasonable cause to suspect of being a habitual idler ; and if such person neglects or refuses to give his name or address as afore- said or gives a name or address which the constable has reasonable [ grounds for believing is incon-ect, the constable may arrest such person and take him before a Magistrate or Justice to be dealt with according to law. 5. — (1.) On the appearance before a Magistrate of any person who is charged with being a habitual idler, such Magistrate shall hear and determine the charge. (2.) The|prosecutor shall not be bound to prove that such person has no visible lawful means of subsistence or habitually abstains from work, but it shall be for such person to prove that he has Lwful means of subsistence or that he doe^ not habitually abstain from wcrk. Short Title. Interpreta- tion. Summons to suspected habitual idler. Constable n,ay demand name and address. Determination of whether person is habitual idler. 108 TBINIDAD AND TOBAGO BULLETIN. [XVIIL 2. How habitual idler dealt with. Detention in settlement. Settlements. Kegulations for govern- ment of settlements. Punishment for breach of regulations. 6. — (1.) If the Magistrate decides that any such person is a habitual idler, he shall inform him of the fact, but shall adjourn the proceedings for a naonth or for such further period as to the Magistrate seems proper, to allow of such person obtaining or endeavouring to obtain work during the period of such adjournment. (2.) At the end of the period of adjournment the case shall again be called on, and if any such person does not satisfy the Magistrate that he has obtained or endeavoured to obtain work, or if such person does not appear at such adjoui'nment, the Magistrate may deal with him as in the next succeeding section mentioned. (3.) It shall be lawful for the Magistrate to accept such evidence, whether strictly legal or not, of the fact that such person has obtained or has endeavoured to obtain work as the Magistrate thinks fit. 7. If any such person does not satisfy the Magistrate that he has obtained or endeavoured to obtain work, or if he does not appear at the time and place to which the proceedings have been adjourned, the Magistrate may order him to be taken and detained in a settlement as hereinafter in this Ordinance provided, for any period not less than three months or more than twelve months. 8. For the purposes of this Ordinance the Governor in Executive Council may by proclamation declare anj- area to be a settlement within the meaning of this Ordinance. 9. — (1.) The Governor in Executive Council may make regulations for the management of settlements, and may, but without limiting the general power of making regulations conferred by this section, make regulations for all or any of the following purposes : — (rt.) For providing for the appointment and remuneration of officers of such settlements ; (b.) For providing for the discipline of persons detained in any such settlements ; (c.) For providing for the method of housing and rationing of such persons ; (d.) For providing for the work to be jierformed by them, and for the awarding of remuneration to those behaving and working satisfactorily ; (e.) For allowing of such persons being emploj'ed away from a settlement before the expiration of their period of detention therein, and for the providing for the times and conditions of such employment and of their return to the same or another settlement ; (/.) For providing for the arrest of persons deserting fi'om any such settlement, or employment. (2.) All such regulations shall be published in the Boyal Gazette. 10. — (1.) Any person detained in a settlement commiting any breach of a regulation under this Ordinance is liable on conviction before a Magistrate to imprisonment with or without hard labour for any term not exceeding one month. 1919.] HABITUAL IDLEBS. 109 (2.) At the end of any period of imprisonmenj awarded under this section, any such person shall be conveyed by a Warier or Constable and delivered to the person in charge of the settlement in which he was originally detained to complete the term of service there to which he was originally sentenced. (3 )_((,.) The Magistrate before whom any such person is con- victed may, in lieu of ordering him to be imprisoned forthwith, direct that execution of the sentence of imprisonment be postponed for a period of three months. (6.) If such person behaves during such period to the satisfaction of the officer in charge of the settlement, such officer shall so inform the Magistrate, and no further steps shall be taken to carry the sentence into execution. (c.) If the officer in charge of the settlement reports that the person convicted has not behaved to his satisfaction, then the sentence of imprisonment shall be carried into execution. 11. Any person convicted before a Magistrate of being a habitual idler after detention in a settlement is liable to imprisonment with or without hard labour for any term not exceeding three months. 12. Every proclamation under this Ordinance shall be published in the Boyal Gazette ; and a production of a copy of the Boyal Gazette containing any such proclamation shall be jjnwrr /acie evidence in all Courts and for all purposes whatsoever of the due making and tenor of such proclamation. 13. The procedure in respect of offences under this Ordinance shall be that laid down in the Summary Conviction Offences (Procedure) Ordinance, (No. 1). Second conviction. Publication and evidence of proclama- tions. Procedure. 14. This Ordinance shall commence on a day to be fixed by the Commence- Governor by Proclamation in the Boyal Gazette. ment. Passed in Council this Nineteenth day of April in the year of Our Lord one thousand nine hundred and eighteen. J. M. FARFAN, Acting Cleric of the Council. 110 TRINIDAD AND TOBAGO BULLETIN. [XVIIL 2. HABITUAL IDLERS ORDINANCE. Amendment. TRINIDAD AND TOBAGO. No. 11. -1919. I ASSENT, [L.S.] W. M. GORDON, Acting Governor. 19th IMay, 1919. AN ORDINANCE lo amend the Habitual Idlers' Ordinance, 1918. [19th May, 1919.] Bk it enacted by the Governor of Trinidad and Tobago with the advice and conse.it of the Legislative Council thereof as follows : — Short Tiilc. 1. This Ordinance may bo cited as the Habitual Idlers' (Amend- ment) Ordinance, 1919. nVs,'.".t;,\\?9 nF 2. SecLion 2 of the Habitual Idlers' Ordinance 1918 is amended by Oidinniicu 7 striking out the definition of "Habitually abstains from work." o!' l!)!S. KogiilitloiH to 3. Tlie following sh 'Jl be read as sub-section (H) of Section 9 of the heM.l.i.-e-, to Habitual Idlers' Ordinance, 1918 ; il;s;ill()\v,iiico l,v llii (^.) All such regulations shall be subject to disallowance by His J^i'j'^^ty. Rlajesty. Passed in Cjuncil t'lii Second day of May, in the year of Our L )rd one tho.isa d nine liunhvd and nineteen. J. M. FARFAN, Acting Clcrh of tlie Council. 1919.] BAIN FALL BE TURN METEOKOLOGY, 111 RAINFALL. RETURN.-APRIL TO JUNE, 1919. Stations. P3 P 01 JS +3 r-( •"3 OC5 North-went Dist7-ict. St. Clair — Royal Uotanic Gardens Port-of-Spain — Colonial Hos[iital ,, Royal Gaol... , , Constabulary Headquarters St. Ann's — Reservoir Maraval — ,, ,, Constabulary Station Diego Martin — Constabulary Station ... ,, Waterworks ... ,, River estate ... Fort George Signal Station ... North Post ,, Carenage Constabulary Station Carrera Island Convict Dei)ot Chacacliacare Lighthouse Santa Cruz — Maracas District. Santa Cruz — Constabulary Station St. Joseph — Government Farm ,, Constabulary Station Tunainma — St. Augustine estate Maracas — Government School ,, Ortinola estate ... ,, San Jose estate ... Caura — Wardour estate West Central District. Caroni — Frederick estate Chaguanas — Constabulary Station ,, "Woodford Lodge estate Carapichaima — "Waterloo estate ,", IMcBean Cacao estate ,, Friendship Hall estate... Couva — Exchange estate ,, IJrechin Castle estate ,, Perseverance ,, ,, Camden ,, Milton Sprnig ,, Constaljnlary Station ,, Esperanza estate Montserrut District. Brasso-Piedra— Mamoral estate j^ La ]\Iaiiana estate Jlontserrat— Constabulary Station Rrasso — La Vega estate Ariina District. Arima— ^\'arden's Office ,, Torreciila estate ,, Verdant Vale estate San Rafael— Constabulary Station Guanapo—Talparo estate ... ,, San Jose Estate ... Taniana — Sta. Marta estate .. ,, La Carona estate ... San Fernando d: P rinccsTown District. Clax ton's Lay ^Forres Park estate Points a-Pierre— Bonne A venture estate ,, Concord estate ,, Plein Palais estate Naparima — Picton estate ,, Usine St. Madeleine estate ... ,, La Fortunee estate ,, Tarouba estate TTiiion Hall estate Ins. 1-G7 2-08 ti-03 1-42 •G8 -.52 •73 l-Gl 1-82 1-78 1-49 1-77 1-12 •45 107 1-03 1-57 nil 1-02 1-74 1-33 2-06 1-57 2-88 2-22 2^12 2 02 1-77 1^72 1 -2!) •'J8 "•.30 1^00 1-37 •38 2^53 2'5U 1^57 2 44 1-33 2-14 1^37 2-54 2-87 2-02 2 -07 2^70 Ins. 3-50 1-22 2-80 3-P2 3-97 3^70 ^•01 5-94 4-92 4 -02 3-11 4^02 4 •70 1-99 3-44 4^26 2-92 1^42 2-74 3-(n 3-78 3-71 3^00 7-34 4-89 5^37 4 03 5-07 4-89 4-20 5 •OS 4-74 5-24 6-01 3-30 9^71 9-80 5-4() 7 •93 4-49 5^39 4-8S 10-00 8-43 9-58 11-98 1101 •81 : 3-50 1-19 2-05 •95 ■43 -96 X I •29 2 I O zz 3-54 5-OG 2-29 2-41 3-9G Ins. G-78 7-50 7 •GO 7-80 8^35 G-G7 7-74 7-58 G-77 G-88 G-87 4^3G 5^40 2-88 G^3S 8-80 10-22 G^42 10 "24 11^01 8^41 10-G5 8-o;5 8-24 8-93 9 1« 11-87 9-44 9-29 8-5G 8-23 11 -68 9^41 9-55 8-42 11 ^98 12-92 11-73 12-34 12-.92 15 -.50 14-13 1411 12-42 13-17 15--0 11-83 8-55 9-4G 9-GG 8-07 10-52 8-17 Ins. 14-35 12-99 15-23 14-55 15^53 13^27 1G^71 19-89 17^17 lG-48 14-39 13-19 17-14 G-59 13-12 19 -74 lG-79 8-93 15-G8 19-80 lG-91 19^iG 15-01 23-57 18-32 19-23 •20-07 19-32 18-87 lG-86 18-40 19-54 20-34 15 -03 27-92 28-75 23-11 25-94 20-50 25-47 24-50 31-44 29-15 29-9G 35-84 31-93 14 -76 15-21 lG-83 19 Gl 14-51 89G I 14^88 Ins. 10 08 12^14 17^12 12-17 21^08 18-24 19-04 2G-4G 2U-55 20-99 15-75 18-90 ::0-21 5-97 19-52 21 ^03 15^40 10-97 14-75 22-4G 19-82 18-83 18^08 20^55 ]5^G1 15-77 20-47 17-27 No record 11^75 17^41 12^40 8 -30 17-98 •23-11 i:V55 15-80 33-05 29 -(^ 21-40 29 40 24-55 29-55 27 -21 33-21 31-25 3G-23 43-82 37 -Gl 18-07 21 -48 23-33 i.s-:?3 2311 22-55 18-40 2i-9fi 112 TRINIDAD AND TOBAGO BULLETIN. [XVIII. 2. '19.] RAINFALL RETURN-APRIL TO JUNE, 1919.-Continued. Stations. . ® -^ « t^C Oh ^ 6 Janua to Jl 1919. 2 oS _ -Ij a ^ ^ 4J 1-H -San Fernando and Princes Town District. — (Contd.) Naparima — Palmiste estate ,, I.ewisville House ,, Hermitage estate ., Petit IMorne estate Piinces Town— Ciaignish estate ,, Cedar Hill estate ), "Williamsville estate >, Esmeralda estate ,, New Grant estate n Constabulary Station ,, Hindustan estate ,, La Retraite estate ,, Malgretoute estate Friendship & Ben Lomond estates Los Naranjos estate Poole — El llosario estate South-west District. Oropuche — Constabulary Station ,, Pluck estate Siparia — Constabularj' Station ,, Alta Gracia estate Guapo — Adventure estate I'oint Fortin— Constabulary Station Erin — La Hessource estate La Union estate Luhistr}- estate Cedros — La Retraite estate ,, Beaulieu estate „ Perseverance estate ,, St. Marie estate „ Constabulary Station ,, St. Quintin estate Icacos -Con.stance estate Irois — Government School South Coast. Moruga — Constabulary Station L\ist Coast. Matura-LaJuanita estate Manzanilla— Constabulary Station ,, Indrasan estate Sangrc Grande — New Lands estate ,, Evasdale estate ,, Grosveuor estate ,, San Hilario estate ,, San Francisco estate Mayaro— Constabulary Station North Coast. Blanchisseuse — Constabulary Station ... Grande Rivifere — lion Plaisir estate Toco — Aragua House ,, Coustabulaiy Station Point Galera — Light House Tohago. Tobago— Hermitage estate ,, King's Bay ,, ,, Roxburgh ,, Lure estate ,, Botanic Station ,, Government Farm ,, Lowlands estate ,, friendship ,, ,, ^Riversdale ,, ,, Bon Accord ,, Ins. •77 ■80 •88 •35 1-07 •78 3^25 5-63 2-11 •43 1^37 2^78 •80 1-46 1-.38 •67 1-29 •25 •96 VU 1-09 i-'n ro7 1-31 •76 1'07 •67 •09 •52 •70 •79 2 •SO 2^20 2^59 2^19 •i-ba 370 2-82 3^95 •98 •97 2^18 •55 •54 2^25 3-58 4-82 2-90 1^88 "•96 2^59 I.,8. Ins. 5-27 10-77 5-33 11-41 3-34 8-78 5-49 11 71 5'78 10-93 3-94 10-40 13-70 O'.ll 12-41 4-37 8-60 C-55 9-95 0-53 1570 1^88 11-17 ... / ■()/ 5-73 12^51 1 1-04 5-92 4-75 5-10 4-32 8-26 2-55 3-35 3-32 7-09 6-50 6^50 0-88 6-10 0-(i6 416 8-68 11-00 8-48 4-57 9-20 10-11 10-35 8-78 10-08 7 05 0-87 12-52 9-40 9-48 8-68 9-45 8-64 6-26 5-31 5-36 608 3-37 8-61 5-85 10-90 0-58 7-74 7-34 9-73 9-02 9-38 10-11 8-70 8-41 9-24 8-55 10-46 8^95 12-56 11-91 9-23 10-74 12-91 11-87 10-67 13-05 10-04 9-78 9-74 8-03 7^46 10-08 8-83 8-44 7-38 5-10 5-87 Ins. 20-53 22-48 15-47 2172 21-09 21-56 25-20 16-42 21-53 30-56 16-53 23 01 8-21 19-94 13-33 21-48 14 77 20-30 16 •02 1.5^59 21 -76 19-60 18-92 19-38 20-03 18-00 19-68 22 •96 31-01 28-11 20-51 3371 32-15 27-34 33-15 21-78 24-41 30-17 21-75 20-69 28-38 27^70 27^49 18-28 13-57 1471 'ns. 23-73 21-90 21 -.57 17-80 24-70 21-54 2474 34-78 20-44 25-87 40-13 25-04 35-24 25-69 24-19 27^98 29-14 22-78 24-43 22 -8() 24-06 25-00 28-12 1971 24-09 2277 23-91 50-38 24-40 23-96 -03 -01 44 02 ■37 72 59 07 00 39-24 35-;54 31-20 26-81 34-51 31-87 31-21 20 00 19-00 21 -82 2270 22-19 17-95 (Bulletin, Department Agriculture, TrmtcJarftt- To/zt/i/o, pp. 45-112. Issued Sept. 8, 19). CONTENTS. I'agf. Notes— Froghopper Investigations; Agriculfcural Credit Societies; Staff Changes ; Ground Provisions Depot ; Empire Day Trees. W. G. Freeman ... ... ... 45-46 Agricultural Credit Societies: Cane Farmers and Co-operation. W. G. Freeman .. 47 Sugar : The Relation of Eoot Fungus to Froghopper Bhght of Sugar Cane in Trinidad. C. B. Williams ... 52 Report on nn Investigation of Frogiiopper Pest and Diseases of Sugar Cane in Trinidad. W. Nowell ... ... 67 Sugar Cine Varieties and Froghopper Blight in Trinidad. C. B. Williams ... ... ... ... 70 Plant Diseases and Pests : Control of the Cacao Thrips in Trinidad and Tobago. F, W. Urich ... ... ... ... 84 Rice Rice Experiments 1915-1918. J. de Verteuil and L. A. Brunton ... ... ... ... 93 Agricultural Legislation : Truck Ordinance 1918 ... ... ... ... 104 Labour Exchanges Ordinance 1919 ... ... ... 106 Habitual Idlers Ordinance 1919 ... ... .. 107 Do. . do. (Amendment) 1919 ... ... 110 Meteorology: Rainfall Return— April to .June, 1919 ... .^. 111 Part 3.] 1919. [Vol. XVIII. BULLETIN OF THE DEPAETMENT OF AGEICULTUEE, TEINIDAD & TOBAGO. Issued hy the Department and Board of Agriculture. Editorial Committee. W. G. Freeman, B.Sc.A.R.C.S., FX.S., Z)iVec 2fl-7 70-3 10 > 1 7 18-4 sro Selected as the "St. Ann's"^ Avocado.- -See Fig. 4. (1) Average of three fruits. — — 6 — ,. . A — 'I — 3 1 — — 1 ■"-" . Fig. 2. — Poor Kinds of Avoiwdcs. On the left No. 13 of the table above. Weight of fruit only 7 oz. with 3 1 "8 per cent, of stone. On the riglit No. 8. AVeiglit of fruit 1 lb. (if whicii lu) less than 4'2'o per cent, is stone. The edible pulp of |No. 8 at the sides is but little over half an inch in tliickness. WIP,] THE AVOCADO IN TRINIDAD ,(■ TOBAGO. 119 il ili l ililiiil III imi 'i ililililii ?^)^ Fig. '6. — Msdzu.m Kin'ds of Avocados. On thelefl No. 11 nt" the tabl - on p. IIS. Weight of fruit 15 oz. of wliich stoue 27 2 percent. In centre No. 12. Weight 11 oz. 2) per eenl. stoae. Cn left a bottle neckee left the " St. Ann's " Avocado. No. 20 table p. 118. Weight 1 lb. 7 oz. with stone 184 per cant. On tlic right the "River" Avocado. No. 14. Weight lib. 12 oz. and stone only 14-6 per cent. These "are the two Avocados now distributed by the Department as budded plants. 120 TBINIDAD AND TOBAGO BULLETIN. [XVIIL 3. This example from Eiver will serve to^illustrate the origin of named varieties, here and in other countries, namely by the selection of the best of a large number of seedlings. Then having found the desirable kind, fix it by budding. The next step at River will be to cut down the poor trees, wait until they throw new shoots from the cut trunk, as they do very readily, and then bud on these from the selected trees. The poor trees will thus be converted into good varieties. One hundred and fifty budded plants have also been put in at River estate during the last two seasons. A stage in the process of conversion from bad to good may be seen at the present time at Mrs. E. StoUmeyer's garden at Diego Martin. Of the trees originally there the good varieties have been selected and left. Of four bearing trees the weight of single fruits ranged from 14 oz. to 1 lb. 3 oz., the average being 1 lb. 1 oz. The poor trees have been cut back and budded, by Mr. Bailey, and at eighteen months after budding I was shown new trees, twelve to fifteen feet high, grown from the single bud. Particulars of two other avocados growing in the garden of my official residence are also given in the table (Nos. 19 & 20). Their fruits weigh 1 lb. 4 oz. and 1 lb. 9 oz. respectively. Both are of excellent flavour. One (No. 19) is a purple thin skinned variety, whilst the other CNo. 20) is a green kind with a thicker, harder skin, very firm flesh and a fixed stone. It appears a very good type not only for local use, but also for exjiort, should such a trade develop later. This type has been selected for propagation and budded plants from this tree are distributed by the Department under the name of the " St. Ann's " Avocado. It is not improbable that a seedless avocado may be obtained. Occasional seedless avocados have already been reported from the United States, and Honolulu, and should a tree or even a single branch of a tree be found bearing regularly seedless fruits the type [could doubtless be fixed by budding. Ko far as I am aware this has not yet been achieved. Another point to select for is early or late bearing. The avocado is a perishable fruit, and there is a tendency for the market to be glutted at one season, with correspondiirgly low prices, and a great scarcity at other times with comparatively high prices. Trees which bear earlier or later than usual are accordingly desirable, and watcli should be kept for such trees and use made of them as sources of bud wood. It will be necessary to extend the observations over two or three years to ascertain that it is not an accidental variation in one season, and the observations are best made where several trees are growing together to eliminate effects of local conditions. In addition to what may be termed the local types, there are a few introduced named varieties in the Colony. The "Pollock" (Fig. 5) a very large fruited avocado, which was introduced by Mr. Eugene Andr^ and thrives well at Port-of-Spain. The " Trapp " a Mexican Variety which thrives in Florida was received from the United States Department of Agriculture in 1912, 1919.] THE AVOCADO IN TRINIDAD d- TOBAGO. 121 lVi .6 5 4 3 Z I Fig. o. — Pollock Avocado, on the left. TitAPP xVvocADO, Oil the right. PROPAGATION OF SELECTED KINDS. To ensure the propagation of plants true to the selected tyfje, the Department of Agriculture relies on budding which has been practised in the nursery at St. Clair Experiment Station for the last four years. The successful budding of the avocado in the West Indies was reported in Jamaica in the Annual Report of the Department of Agriculture for 1903-04, and by Mr. J. Jones at the Dominica Botanic Station in 1912. Difficulty was experienced at Dominicx in budding plants in bamboo pots, and the raising of the stocks in nursery beds was recommended. Locally my attention was directed to the possibilities of budding the avocxdo by s nne results obtained hy Mr. Bailey on old trees at Dr. Senior's Estate at Four Roads, Diego Martin. The work at St. Clair has been actively taken up by Mr. E. O. Williams who finds that budding of plants in bamboo pots is quite successful, provided young stocks are used. A desoript'on, bv Mr. Williams, of the method -i employed follows (pages 125-8). I need not say more here excepting that local experience has proved that it is possible both to bud young plants, and to bud an old tree from a selected type and so convert a plant from a poor to a good kind. CULTIVATION. The Avocado needs no very special care in cultivati )n ; at the same time it thrives locally much better in some districts and situations than in others. On the poor soil of parts of the Northern range in Trinidad it does exceedingly well and vigorous plants may be seen on the hillsides at the back of Port-of-Spain, and in the adjacent valleys of St. Ann's and J22 TEINIDAD AND TOBAGO BULLETIN. [XVIII. 3. Diego Martin. The chief essential as regards soil appears to be that the drainage should be good. If budded plants are vised, a distance of about twenty-five feet apart each way is recommended. Like most trees they respond to cultivation and thrive better if not allowed to be smothered in grass and bush. The best results will doubtless be obtained by growing leguminous catch crops on the ground between the young trees, preferably such as the sword bean {Canavalia cnsiformis) which smother weeds, prevent soil wash, and yield a useful crop. If circum- stances do not permit this, a space at least as wide as the spread of the branches should be kept clean around each tree. Seedling avocados begin to bear in about six years, and budded plants usually aboiit two years earlier. The Avocado is often irregular in bearing, sometimes it flowers profusely and sets but little fruit. Indeed it has been suggested that the name avocado is derived from "Avocat" from the fact that as is sometimes the case with legal proceedings the fruit borne is by no means commensurate with the early promise. LOCAL DEMAND. The demand for avocados is greater than the local supply in normal years and there is a considerable importation of the fruit, principally from Grenada. In Port-of-Spain there is no difficulty in disposing of good class fruit at prices from about 3c. to Gc. each. In the country districts the question of transport has -to bo taken into account. With all fruit, but particularly with the avocado, this means careful picking, handling and packing to ensui-e arrival at their destination in good condition. It is hoped that the formation of a Trinidad and Tobago Fruit Growers Association, may help in placing the avocado industry in a better position. In a season when avocados are plentiful one hears of persons who have quantities of fruit they do not know what to do with, and who will probably be disappointed at the results of casual efforts to find a market. Proper organisation is particularly necessary in dealing with perishable products. FOOD VALUE OF THE AVOCADO. The edible portion of the avocado varies fiom a little under one-half to over three-quarters of the weight of the whole fruit, according to the thickness of the rind and the relative size of the seed. The following interesting ttible, showing the composition of the edible portion compared with other foodstuffs, is taken from The AvocarJo in Haicaii, Bulletin 25 of the Hawaii Agricultural Experiment Station. 1919.\ THE AVOCADO IN TBINIDAD d- TOBAGO. 123 Percentage Composition of the Edible Poktion of the Avocado jAND Other Foods. Carbohj-drates. Fuel value per lb. Food Products. Water. Protein. Fat. Nitro- gen free Crude fibre. Ash. extract. Calories.. Avocado (analysed at the Maine Station... 81-1 1-0 10-2 6 •8 0-9 554 Avocado (analysed at the Florida ^^tation) 72-8 2-2 . 17-3 4-4 1-9 . 1-4 854 Pickled ripe Olives .. 65-1 15-7 25-5 3 ■7 1,201 Pickled green Olives... 78-4 16-9 12-!) 1 •8 G8a Ajiples 84-6 •4 13-0 1-2 •3 29a Bananas ... 75-3 1-3 •6 21-0 1-0 •8 460 Pears 84-4 •G "5 11-4 2-7 •4 295 Coconuts . 14-1 5-7 50 -G 27-9 1-7 2,760 Chestnuts fresh 4.5 -0 G-2 .5-4 40-3 1-8 1-3 1,125 Potatoes ... 78-3 2-2 •1 18-0 •4 1-4 385 "Wheat flour 12-0 11-4 1-0 74-8 •3 •.J 1,G50 As in most succulent fresh fruits there is a high percentage of water. Wliilst liowever the food value of most fruits is due to the presence of sugars, and fat or oil occurs in them to only a small extent, the avocado is mainlj- valuable for its comparatively high fat content. Analyses of 28 different varieties made in California byM. E.Jaffa (D showed a range of from 9-8 per cent, to 29-1 per cent, with an average of 20"1 per cent. " The only fruit comparable with the avocado in this respect is the olive." LOW OIL CONTENT OF TRINIDAD GROWN FRUIT. In looking up information on the oil contents of the Avocado I became interested in the series of analyses referred to above by Mr. E. .Jaffa. From the results obtained in efforts to extract the oil, it seemed very improb;ible that Trinidad fruit contained anything approaching this amount of fat. As on further investigation I could find no records of the composition of Avocados grown in the wet tropics, but only from sub-tropical regions such as Florida and Califoriiia, it seemed very desirable to obtain some accurate information of West Indian avocados. Accordingly I asked Mr. H. S. Shrewsbury, Acting Government Analyst if he would make some analyses. This he did and his results are appended (pages 184-5). (1.) The Avocado in Californin, Part ii. Composition and Food Value. Bulletiu 254, Ag. Exp. Station, Univ. of California, 1915. 124 TEINIDAD AND TOBAGO BULLETIN. [XVIII. 3. They show that avocados grown in Trinidad contain much less oil than in California and Florida. Thus of those analj'sed by Mr. Shrews- bury the richest in oil was the " River " 7"6 per cent, which is over "2 per cent, belotu the minimum of the California set. In order to test whether the low oil content was a character of the local -varieties only, or was to be found in introduced varieties as well, fruits oi the " Trapp " avocado were included for analysis. The Trapp avocado at St. Clair is a budded plant presented by the United States Department •of Agriculture and as Mr. Jaffa gives an analysis of the " Trapp" grown in California in his series, our plant afforded a good opportunity for com^^iaring the oil content of fruits of budded plants of the same variety grown in Trinidad and California. In California the Tra,pp is of low oil content, 9'80 i.e. the lowest of the set i-eferred to above. The Trinidad fruits of the Trapp contain only 2"5 per cent, of oil ! The comparative figures are given in detail on page 135. Accounts have reached me of an excellent salad oil being prepared from the avocado. I have been unable to get any samples or to ascertain exactly how it is obtained. Mr. J. de Verteuil, Acting Assistant Director, prepared some at the Government Laboratory but it was most unpalatable. AVOCADOS FOR EXPORT. It is recorded that there was formerly a small, but steady export of :avocados from the West Indies to New York, but that this has almost ■ceased, the reason given being the development of the industry in Florida and California. In November, 1913 Prof, Carmody took with him to England two Inches. Inches. Kovember 8, 1918 47 41 87-2 3 G-4 - 3 G-4 9 3-78 13, 1918 133 94 70-7 32 24-0 7 5-3 7i 4-41 14, 1918 100 58 58 40 40-0 2 20 7h 1"55 25, 1918 27 22 81-5 5 18-5 2 36 December 4, 1018 50 47 94 3 r, 1 buds just bursting 5, 1918 25 23 92 2 8 1 do. Total ... 382 285 74-<; 85 22 3 12 3-1 Of the failures, 35 were rebudded with the following results : December 30, 1918 35 23 GoT 12 343 IJ -July-August 35 Stock 1(J to 12 montlis old. * G 17-1 29 82-9 t: •25 1-fif. *3 have since died from stock dying back below the point of union, i' Aver.\ge for three. The distiibution cf budded plan's given in th'j fLl'.owing table shows how wit'i the bu;ldiag o; th? Avocalo, th?rj has been a decrease in the sale of seedlings and an incr:!ase in tha' of budded plants. Number of Plkxts Distributed from St. Clair. 1911 1912 1913 1911 1915 1916 1917 1918 1919 Budded 4 107 14;5 210 379 Seedling. 363 107 49 376 85 49 20 1919.^ BUDDING THE AVOCADO. 127 ADVANTAGES OF BUDDING. The advantages of budding plants over seedlings are: (1.) To ensure a select variety being kept true to type. An increasa was recently seen when a fruit from a seedling avocado tree weighed 2 lb. 2 oz., and the parent tree bore large fruits with seeds about the size of walnuts. On opening the fruit from the seedling tree it was not found to have the good characteristic of its parent, as of the 2 lb. 2 oz. of the fruit 10^ oz. was seed. See Fig. 1. (p. 116) of a fruit of the seedling. On page 120 more has been said on this point and attention drawn to select varieties of which the^' are many in Trinidad for pi'opagation. (2.) To ensure early fruiting. Sesdling and budded plants of the same kind growing side by side in the St. Clair Experiment Station have shown that whereas some of the budded plants conmienced to fruit at three years of age, the seedlings although larger trees have not j'et borne in their fifth year. Seedling trees can not be relied upon to fruit at as early an age as can budded plants. (3.) To jjrolony th" fruiting season. As is well known there are some varieties which fruit in Trinidad when the main crop is out of season. I was shown good fruits at Princes Townjin January gathered from a single tree. A tree of this kind should be watched to see if it fruits each year out of season. If such is found to be the case it could be propagated by budding and^fthis characteristic thus kept constant. (4.) To obtain a hardier root stocli. An advantage usually derived by budded plants viz : to bud on to a hardier root sto^k or one resistant to disease does not as yet appear to be important in the case of the Avocado as little diffjrence is to b3 noticed in the constitu- tion of different varieties. The only selection of stocks that can at present be advised is to choose seedlings for the purpose with strong ■vigorous shoots. B itter primxry successes are also obtained wiien budding on such stocks. METHOD OF BUDDING. The method used for budding is the same as that generally adopted for roses and citrus, viz. : the T method. The patch method which is successful with Cacao is also sometimes used in the cas3 of thick stocks. Selection of Buds. — Branches from which buds should be taken must be chosen from mature wood about twelve months old ; this is usually of a light brown colour. It is preferable to select buds from which the leaves have fallen, or to cut off the leaves leaving a few inches of the petiole attached, a few weeks before the buds are required. The buds should then be taken off with about i^ to f of an inch of bark and •inserted in the usual wav. 128 TBINIDAD AND TOBAGO BULLETIN. [XVIIL 3. Selection of Stocks. — In regard to the stocks on which the buds are to be inserted we have found it very important if success is to be assured that the stock be young. The proper age to bud and that at which to expect the best results is when the seedUngs are from six weeks to five months old. In old stocks the chief reason of failure lies in the susceptibility of the bark to split when making the incision, resulting either in failure or a poor union. This does not happen in the case of young stocks. The ideal stock for use is one with a strong thick shoot. Buds will unite much better and make stronger plants on stui-dy stocks. The seed required for stock purposes are sown and grown in bamboo pots. The method of top-working old trees by cutting them back and allowing shoots to grow which are then budded on, agrees with this in principle as it is the young shoots springing from the old pollarded branches upon which the buds are inserted. Season Tor ]3uddinct. — Another very important factor and one which must not be overlooked is the season in which to bud. Unless a glass covered shelter is available in which to place the plants before a union has been made budding must be deferred till the early months of the dry season, selecting seeds from late fruits for use as stocks to allow of them being of the right age. Oar experience at St. Clair has been that, even after budding under shelter, if the plants are exposed to heavy rains at too early an age many are lost. Growth of Buds. — The most striking point about budding of the avocado is the marvellous rate of growth of the shoots once the buds have made a union with the stock. Occasionally we find buds make a good union but do not burst into growth, and on examination it is seen that the bud has dropped from the piece of bark inserted. The chief cause of this is through the bud being taken from shoots which are too young. After the bud has made a un:oa with the stock the latter should be trimmed off four or live inches above the point of imion. It must not be trimmed back completely till the bud has made several inches of good strong growth and made a complete union with the stock. If the stocks are cut back closely before the hwda have properly united the stock often dies back below the incision of the bud. This is one of the most important points in connection with the budding of the avocado. As in the case of other bu Ided and grafted plants a close watch must be kept for suckers which should be rjmoved as soon as they appear. 1919?, 12? INSECTS AFFECTING THE AVOCADO IN TRINIDAD AND TOBAGO. By F. W. Urich, Entomologist, Board of Agriculture. The full grown avocado tree is fairly free from insect pests and only occasionally suffers from scale insects with the resulting black blight and from the webbing caterpillars ; in the early stages of its growth the avocado is more likely to suffer from insect pests and the seedling, the recently budded plant and the young tree cut back to form low branches should always be carefully examined for the first appearance of insect pests. During the dry season scale insects are under favourable conditions for increase and at the opening of the rainy season cater- pillars may occur in numbers. ANTS. The stinging ant {Soleno-psis cjeminaid) is a serious pest to young plants not only does it encourage and protect all kinds of mealy bugs and scale insects but it will also bite off young bark from shoots and stems of the trees. In bad attacks fairly large branches can be entirely destroyed. Stinging ants can be controlled by destroying the nests with carbon bisulphide and cyanide of potassium or sodium. The carbon bisulphide treatment is too well known to require descrip- tion. Cyanide of potassium is also effective. For use take one ounce of the salt and dissolve it in one gallon of water : pour the solution into the nest until the ground is saturated. When using cyanide bear in mind that it is a deadly poison. Carbon bisulphide and cyanide will kill plants when the roots are touched. Other treatments are boiling water and puddling when nests are not situated in masonry. If a little resin wash is added to the boiling water it will make the treatment far more effective. When on the roots and stems of plants they can be sprayed with resin wash and nicotine, but frequent applications may be required as they return very soon from neighbouring nests. Trees can be protected by banding the stems and trunks with tree tanglefoot see formula ] , 2 and 3. Napthalene flakes dusted around a plant will keep away ants for a few days. Another species of ant found on the avocado tree is the acrobat ant, {Creynastog aster hrevispinosa) which is not as bad as the stinging ant as- it confines itself to the care of scale insects and mealy bugs and does not gnaw the bark of the tree. It makes its nest under loose dried bark and in rotten wood resulting from badly dressed pruning wounds or from dead branches left on the trees. Nests should be cut out as much as possible and the place painted over with crude oil or strong resin wash. SCALE INSECTS AND MEALY BUGS. The following scale insects and mexly bugs are found on avocado : — 1. Pulvinaria pyriformis. 2. Aspidiotus destructor. 3. Saissetia nigra. 4. Pseudococcus nipcB. 5. Pseudococcus citri. Pulvinaria pyriformis is the most common of above and there is hardly an avocado tree that is entirely free from it. In severe infestations it causes black blight. 180 TRINIDAD AND TOBAGO BULLETIN. [NVIIL 3. Most of the scale insects and mealy bugs can be controled by natural enemies by keeping away ants from the trees. When numerous they can be sprayed with nicotine sulphate in combination with resin wash or soap, see formulae Nos. 4 and 5. WEBBING CATEEPILLAES. {Stericia aUnfasciata). Sporadic attacks by these caterpillars take place, and young leaves and flowers of tall trees are destroyed. The caterpillars are gregarious and live in nests made by webbing leaves and branches with a tough silk, see fig. 2 which represents a single net while fig. 1 shows how a tree can be affected. The caterpillars, see fig. 3, are about one inch long when full grown, the general colour is dark brown with longitudinal yellow lines, the head is black and yellow. As a rule the caterpillars are controlled by natural enemies of which a Tacliina fly see fig. 5 is the most important. The moth expands about an inch, its fore wings are light brown with dark brown mottlings, the hind wings are white with a slight purplish fringe. The male see fig. 4 has two conspicuous wliite spots on the fore wings which are absent on those of the female. The caterpillars can be destroyed by cutting off and burning the nests, but this has to be done with care and despatch as the caterpillars when alarmed let themselves down to the ground by silken threads and < O u 1919.] FUNGOUS DISEASES OF THE AVOCADO. 133 TREATMENT. The treatment for this disease follows closely that given for the Anthracnose of the mango. Sprayings with Bordeaux mixture must be made continually from the time of flowering until the fruits are mature. The frequency of the application must be determined by weather conditions. The more humid the weather, the greater the number of sprayings necessary. If avocados are to be shipped for any distance, it is quite important to send fruits which have been sprayed. Though the skin may seem perfectly sound, the fruit is practically always infected by this fungus, for which the best conditions of growth are given when packed in crates or boxes. THE DIE-BACK OF AVOCADOS. Avocado shoots dying back are of frequent occurrence throughout the colony, and a microscopic examination has shown that these twigs are infected by the fungus Diplodia cacaoicola, which causes the " die-back " of cacao and rubber. Whether this fungus is able to get into uninjured shoots, has not yet been proved, but it is very probable that it gains entrance into the very young tissues through wounds made by the Anthracnose fungus, and when once in the shoots, grows rapidly down toward the trunk of the tree, killing the shoots for a distance of two or three feet from the tip. The same fungus has been known to attack budded avocados, gaining entrance probably through the cuts made in the operation of budding. The same treatment recommended for the Anthracnose will serve to combat this disease. 134 TB IN ID AD AND TOBAGO BULLETIN. [XVIIL COMPOSITION OF TRINIDAD AVOCADOS. By H. S. Shrewsbury, F.I.C, F.C.S., Acting Governineiit Analyst. The following is a report on Avocados grown in Trinidad, received from the Acting Director of Agriculture : The fruits were gathered somewhat green and allowed to ripen until lit for the table. At this stage they were analysed. The table below shows the number of fruits in each sample, with individual weights of whole fruit, skin, seed and pulp and percentage proportions of the bulked parts of tlie fruits. For comparison with table showing analysis of pulp, the samples are arranged in the same order, viz., in descending magnitude of fal percentage. COMPOSITION OF FRUIT. 6 Varittv. "Weight in ( irammes of Bulked percentage composition. s (11 r, 33 80 405 5-0 15-7 78-7 o (127 oC. 105 480 1049 Tollock 1 cm 07 88 543 7'S <)•() 82 '3 2 78G 50 .59 ovv l()»t St. Ann's 1 521 45 81 395 2 022 .5() 75 491 9 15-2 75-8 8 (>'J7 (15 122 510 104S Trapp 1 2 233 235 27 25 02 72 144 138 11-2 28-5 CO-3 1077 Trapp 1 ir.n 21 48 100 2 222 -2i\ 73 12:; n-2 29-2 59-0 3 317 32 87 199 ANALYSIS OF PULP. The pulps from all the fruits in each sample were analysed, when the following data were obtained : — Composition of Pulp. bv^lked and Percentage of Sohdile 1 Carbohydrate.". A'arietv. , ^ . educing Sugar. on-reduc ing Suga op o to a u o o 1 o -s 1 o o f? O tf ^ ^ a ?= Ph < plH River Estate ... 84-7 7 2-9 0-0 0-9 0-7 1-0 1-3 0-3 27 No. 19 82-4 6-5 3-5 1-3 10 2 1-2 1-2 0-3 28 Pollock 80 1 1 2-9 11 1-1 2 1-0 10 0-5 23 St. Ann's 80-4 5-2 2-7 0-8 1-3 1-7 0-7 0-9 0-3 22 Trapp Trapp 89-5 2-5 2-3 1-0 0-4 0-9 0-9 0-8 01 1(> 89-4 2-5 3-5 0-0 11 0-5 0-8 1-3 0-3 15 1919.] COMPOSITION OF TRINIDAD AVOCADOS. 135 Food Units. For comparisoa with tlie food units, the figure for pickled ripe olives may be taken as 81, indicating that olives have thi-ee tim3s the food value of the best variety of avocado analysed, viz.. River Estate. The comparison is not strictly fair, since olive oil is essentially different from avocado oil, which resembles coconut oil in type. The comparison is probably mifavourable to the olives. Data Comparkd with American Data. Twenty-eight varieties of avocado, analysed at Berkeley, California (University of California Publications, Bulletin 254) ranged from 61 to 79 per cent, of water, and 10 to 29 per cent, of fat. As one of these varieties was the Trapp, a direct comparison may be made between data for Trapp grown in California and iu Trinidad, as exhibited in the following table : — COMPAKTSON OF TBAPP, CALIFORNIA WITH TUAPP, TRIXIDAD. Vaiietv, o S to ^^ it > Percentage of m m Percentage Composi- tion of Pulp. Percentage Composition of Dry Pulp. CS ^ o lo o 0-1 .£3 T- ^ ^M 1 O -+3 o Cm J3 CD Califort.ia. Tiini(l:iil 638 8-2 20-3 71-5 1()9 222 11-2 28-:) (JO -3 2s:^ 235 11 2 2!) -2 m-G 317 89 -5 ! 2-5 1 89 -4 1 2-5 0-1 1-.; 0-8 4(i-0 42-7 71 r.-i 1-8 0-1 23-8 58-0 17 1 C.-o i 1-3 0-3 23 -f) 01 -3 12-3 4-2 1-1 2-8 The California fruit is nuich heavier, with Tghter skin and seed and heavier puli). Not only is there a considerably larg;3r percentage of ))ulp, but the pulp itself is not so watery as that of the Trinidad samples, and contains much more oil. Conmaring the dry pulps, the Californian sample contains twice as much oil and a nmch heavier ash, with smaller percentages carbohydrates and proteins. Comparing the five varieties gr->wn in Trinidad with the twenty-eight grown in California, the lowest percentage of water in the Trinidad samples (82-4) is higher than the highest figure for the Californian samples (79): similarly the highest oil figure (Trinidad)— (7-6) is lower than the lowest Californian figure (10). 136 TBINIDAD AND TOBAGO BULLETIN. [XVIIL 3. SUGAB. SUGAR CANE EXPERIMENTS 1917-19. Trinidad Seedlings & Tests of Varieties. By Joseph de Verteuil, F.I.C, F.C.S., Superintendent of Field Experiments. The report on sugar-cane experiments may be divided into two parts : — (1.) Raising and testing of new seedlings. (2.) Eesults of tests of varieties grown in plots. RAISING AND TESTING OF NEW SEEDLINGS. Seedling canes were raised in Trinidad, on a large scale for the first time in 1895 by the late J. H. Hart, F.L.S, Superintendent of the Koyal Botanic Gardens and continued until 1904. From then no seedlings were raised by Government Officers unlil 1917 when, on the initiative of His Excellency the Governor, the work was resumed by the Department of Agriculture. In September, 1918, the question of raising the seedlings was reconsidered by the Sugar '[Committee of the Board of Agriculture and it was decided that centralization of the work at St. Augustine Experi- ment Station was preferable so that all the work in connection with the raising, growing and testing of seedling canes has now been entrusted to tlie Superintendent of Field Experiments. In addition to raising ordinary seedlings by collecting and sowing arrows from good varieties when the seed is ripe attempts will be made to obtain :— (a.) Natural hybrids i.e. seedling canes obtained by planting some of the best varieties chess-board fashion, and before the flowers open, bagging the inflorescences of two different varieties together so as to ensure that the seedlings obtained are either crosses of the two varieties bagged or self-fertilized. In this case as far as possible, varieties producing a high percentage of sucrose are crossed with varieties giving a high tonnage of canes per acre. (6.) Self-fertilized seedlings obtained by bagging sonie of the best varieties before the anthers open so as to ensure that they are not cross-fertilized. Seedlings Raised in 1917. Out of the seedlings raised and potted in 1917, 1,2.37 were pUxnted out in the field in June, 1918, representing 2.56 natural hybrids and 981 ordinary seedlings. Of these 205 or 16-5 per cent, were selected from their field characters for analytical test and 49 or 3-9 per cent, have been selectsd for a second trial. 1919 A SUGAR CANE EXPERIMENTS. 137 It would appear from the first year's results that certain varieties are useless for raising new seadlings and th3 d3te3tion of good parents seems to be of great importanc2 as will be seen below : Table I. — Sugar-Cane Seedlings raised ix 1917. Pakent <'axe. Number of Seed- lings- planted out in field. Selected for testing from field characters. •jelected for further trialfrom fieldcharac- ters and analytical results. B. G388 ... B. 15G ... H. 27 ... T. 7") ... D. llii .. D. CJ.-i .\ B. G335 D. ()25 X B. G3SS D. G2.'> .\ Dadilla D. (J2.J .\ B. 2US Bourbon ... B. 6308 ... H. ? (1) ... 3 16 112 2 = rs per cent. . 403 24 = .o-'J I (;') 9 = l.j-0 y 00 8 = 13-3 1 = I'G per cent. 28 5 = 17-8 1 = 3G 88 20 = 22-7 5 = 57 ,, 80 12 = l.J-0 5 = G-2 236 90 = .31-5 22 = ""7 ,, 20 4 = 20-0 2 = ]0 7G 31 = 40-8 13 = 17-1 None of the seedlings raised from B.6388 and B. 156 were sufficiently good to warrant the juice being tested. Out of 112 H. 27 and 408 T. 75 seedlings only 2 and 24 respectively exhibited sufficiently good field characters and when these were tested none came up to the mark. Similarly none of the D. 116 seedling past the analytical test out of the 9 selected for their field characters. Only one each of the crosses between D. 625 and B. 6835 and B. 6388 has been kept for a seconrl trial ; this represents 1-6 and 3-6 per cent, respectively of the number grown. Five each of the crosses between the Badilla and B. 208 with D. 625 have been kept for further trial. Out of the 286 Bourbon seedlings raised, 90 or 31-5 per cent, were selected for their field characters and 22 or 7*7 per cent, are being kept for a second trial. Two seedHngs raised from B. 6303 out of twenty are also being kept and out of 76 H. ? seedlings 31 or 40-8 per cent, were selected for analysis and of these 13 or 17-1 per cent, of the number grown have given juice of good quality. The following are the results of the seedlings raised in 1917, which have been selected for their combined field characters and analytical results and are being kept for a further trial. They were planted out in the field from bamboo pots in June 191 8 and were consequently only eleven months old when tested between May 16 and 29, 1919. The rainfall from June 1918 to May 15, 1919 was 51-72 inches but from January to March, 1919 only 1-68 inches of rain fell and during this period the seedlings made very little growth. (1.) A Hawaiian caue received without a number owing to the label having become illegible on the journey. — (,Ei). ) 138 TRINIDAD AND TOBAGO BULLETIN. [XVIIL -7. Table II. — Seedlings Eaised in 1917. — First Year's Selection. o Juice. ■ X ,-j Percentage of (4-1 ' 3 Ptircnt. O 0) • ^ 'S I- •3 s m rr oi 00 c u S 3 S A so 1^ 1:2 Lb. Lb. Lb. T. ,':02 Bourbon 167-0 5-4 64-1 1-0682 16-6 12-73 2-13 1-74 76-7 1 -360 T. ;t.o Boiirt)on 64-5 5-4 68-4 J -06S2, 16-6 13-41 2-45 0-74 80-8 1 -432 T. 370 Bourbon 78-5 4-5 68-3 1 •0()69 16-3 13-72 1-48 1-10 84-2 l-4(;4 T. -Ani Bourbon 81-5 5-1 67 -6 1-0682 16-6 13 80 1-48 1-.32 83-1 1-474 T. 50(1 Bourl)on 113-5 4-7 64-2 1-0687 16-7 14-09 1-40 1-21 84-4 \ -506 T. ;!o4 Bourbon 47 3-9 67-3 1-0674 16-4 14-54 1-26 (J -60 88-6 1 -.552 T. 4!l!) Bourbon . . 168-0 5-4 65-4 1 -0722 17-5 14-72 1-63 1-15 84-1 1-578 T. ;y'.) Bourbon 46-3 3-9 70-7 1-0704 17-1 14-79 1 -53 0-78 86-5 1 -583 T. S(i'_' Bouibon 42-5 5-3 (i6-2 1-0691 16-8 14-81 1-26 0-73 88-1 1 -.583 T. ?,T1 Bourbon .58-8 4-5 66-1 1-0730 17-7 15-10 1-81 0-79 85-3 1 -620 1. 3^5 ]iourbon 49-0 3-1 ()8-6 1 -0735 17-8 15-24 1-88 0-68 85 -(i 1 •(;:i6 T. :i().' Bourbon 76-0 3-8 68-6 1-0744 18-0 15-37 1-81 0-82 85-4 1 -(;5i T. srx; Bourbon 35-7 5-1 68-0 1-0700 18-6 15-48 2-13 0-99 83-2 1-667 T. :57;5 Bourljon 86-5 3-9 70-1 1 -073!) 17-9 15-72 1-48 0-70 87 -S 1-688 T. 3(iS Bourbon 75-5 3-4 68-4 1 -0766 18-5 15-73 1 •()3 1-14 85-0 1 -693 T. 381 Bourbon 41-7 5-2 63-(; 1-0744 18-0 15-90 1.32 0-78 88-3 1 -708 T. 34S Bourbon 64-0 5-3 65-0 1-07()1 18-4 1(;-31 1 -36 0-73 88-6 1-775 T. 37S Bourbon 55-0 5-5 70-9 10757 18-3 16-51 1 -09 0-70 90-2 1-776 T. 4'.)7 Bourbon 101-5 2-7 61-9 1 ■080(i 19-4 16-63 1-09 1 -(J8 85-7 1-797 T. 31)3 Bourljon 38-0 5-4 64-8 1 ■07(;6 18-5 17-03 0-98 0-49 92-0 ] -833 T. 3(;u Ijourbon %-o 3-3 60-6 1 -0810 19-5 17-15 1-.53 0-82 87-9 1 -854 T. 4'j(; Bourbon 147-0 2-6 61-1 1-0797 19-2 17-27 1-04 0-89 89-9 1 -8t;5 T. 413 H. ? 48-0 4-8 64-8 1-0704 17-1 14-89 1-44 0-77 87-1 1 -594 T. S'.t'.l H.? 45-0 3-3 64 -7 1 -0761 18-4 16-65 1-04 0-71 90-5 1-792 T. 40.S H. ? 64-0 4-6 .59() 1-0788 19-0 16-71 0-73 1 -56 88-0 1 -803 T. 3'):) H. ? 24-5 4-1 58-4 1 -0775 18-7 16-87 0-94 0-89 90-2 1 -818 T. 41(1 H. V 28-3 3-1 62-3 1 ■0770 18-6 17-07 0-78 0-75 91 -8 1 -838 T. 415 H.? 37-1 3-4 64-5 1-0761 18-4 17-38 0-47 0-.55 94-4 1 -870 T. 40(i H.? 34-5 5-8 .56-7 1 -0801 19-3 17-41 0-82 1-07 90-2 1 -880 T. 420 u.? 43-7 3-6 ()0-0 !•( 181(1 19-5 17-59 0-98 0-93 90-2 1-901 T. 411 H.? 45-5 3-5 63-.^ 1-0801 19-3 17-65 1-02 0-()3 91-4 1 -906 T. 401) H.? 52-9 4-1 (i3-5 1-0832 20-0 17-70 0-91 1 -.39 88-5 1 -.117 T. 412 H.? 40-5 4-4 64-3 1-0824 19-8 18-29 0-91 0-60 92-4 1 -98(_« T. 4U2 H.? 52-5 2-2 64-0 1-0824 19-8 18-91 0-63 0-26 95-5 2-047 r. 407 H. ? 55-5 3-5 .59-7 1-0932 22-2 20-20 0-3!) 1-61 91-0 2-208 T. 424 P>. G.308 61-9 2-9 67-2 1-0717 17-4 14-78 1-.53 1 -09 84-9 1 -584 T. 422 B. G308 70-0 4.4 68-0 1-0766 18-5 16-45 1-26 0-79 88 -i) 1-771 T. 4(;2 D. 625 X Badilla. 45-0 2-5 62-5 1-0753 18-2 15 -.50 1-75 0-95 85-2 1 -(ilM T. 452 D. 625 -T Badilla. 52-5 2-4 63-1 1-0792 19-1 17-28 1-26 0-5i> 90-5 1-885 T. 459 D. 625 X Badilla. 32-0 2-7 61-3 1 -0828 19-9 18-04 1-14 0-72 90-(; 1 •i)53 T. 455 D. 625 X Badilla. 45-5 2-8 62-9 1-0832 20-0 18-47 0-71 0-82 92-3 2-001 T. 457 D. 625 X Badilla. 25-0 2-8 62-2 1 -0900 21-5 20-07 0-70 0-73 93-3 2-188 T. 473 D. 625 X B. 6835 61-4 4-1 (i5-l 1 -0704 17-1 14-31 1-81 0-98 83-7 1 -532 T. 481 D. 625 X B. 6388 .53-0 2-0 64-4 1 -0761 18-4 16-70 0-87 0-83 90-8 1-797 T. 50? D. 625 X B. 208 .53-0 2-4 67-2 1-0704 17-1 14-55 1-75 0-80 85-1 1-557 T. 491 D. 625 X B. 208 ,55-0 4-6 62-5 1-0775 18-7 15-81 1-(X) 1-89 84-5 1-703 T. 486 D. 625 X B. 208 33-5 2-1 66-0 1-0824 19-8 17-81 0-70 1-29 89-9 1 -928 T. 48f D. 625 X B. 208 25-0 2-1 ()0-5 1-0824 19-8 18-29 0-72 0-79 92-4 1 -980 T. 487 D. 625 X B. 208 32-0 4-6 61-9 1 -0828 19-9 18-43 0-66 0-81 92-6 1-996 Although a few of these seedlings might appear hardly, worthy of' retention it is considered preferable, especially at the start to err on the side of leniency. Generally it will b? seen from the above that the seedlings raised from t'le B mrbo:i gave the largest weight of canes and those from H. ? the best juice. 1919.] SUGAR CANE EXPERIMENTS. 139 The stools of these selected canes have been dug up, divided into"] two or thi'ee according to their size, replanted and carefully labelled on a plan showing the position of each stool. When these canes grow up, cuttings will be planted out in plots about October-November and grown in competition with standard varieties such as Bourbon, B. 156. Badilla, B. 6450 or B.i. 6032. From the results obtained a further selection will be made, only those varieties wliich give very good results will be kept and planted in larger plots. Seedlings Raised in 1918. About 8,000 seedlings were raised in 1918; of these over 3,000 were potted and 2,000 of the most vigorous planted out in the field at the beginning of May, so that when tested next year they will bo fully 12 months old. This year about 50 seedlings were planted out weekly from the beginning of April as an experiment and the results have been so satisfactory that it is proposed in future to plant out the bulk of the seedlings in April instead of waiting for the first rains in May. The greatest danger is that the young plantlets are liable to be cut by mole crickets but these have been successfully kept under control by the use of a protective bamboo collar. The exti-a growth obtained from early planting out more than compensates for the few plants destroj'ed, moreover there is a better chance of the canes coming to maturity, as they will have been thirteen months in the ground when cut for testing. 'o' RESULTS OF TESTS OF VARIETIES. With the exception of Field 7, which was under the control of the St. Augustine Estate authorities, the canes under report were grown at the Experiment Station, St. Augustine, and consist of plant canes, first and second ratoons. Plant canes received an application of pen manure at the rate of about 15 tons per acre. No manures were applied to ratoons and all the canes received ordinary estate cultivation. .During the period under review the cultivation suffered ver3' little from froghoppers, but the Bourbon in Field 10 Valsayn (first ratoons) was severely hit by root disease. The results obtained from the plant canes are recorded in Tables III to V, those from the first ratoons in Tables YI and VII ; Table VIII gives the results for the second ratoons and Tables IX and Xthe average results for plants and ratoons. Information with regard to the date of planting, and testing of the juice is given at the head of the Tables. The plant canes in Field 9, Valsayn, Table III, were 22 months old when reaped. They were planted on June 5, 1917 with the intention of reading them twelve months later but as the Factory finished grinding during the first week of May and the canes were still short it was considered preferable to allow them to stand over. The average yield for the whole field was 32"42 tons of canes per acre. 140 T BIN ID AD AND TOBAGO BULLETIN. [XVIIL 3. •« ^ -^ •aomf in Jg CO rH rH 8 fe 1^ asoaoii;^ O CO CO CO < o rH X X o X CO (U C<1 ^ asojouc; 1— ( ?— 1 CI r-H T-* rH rH rH Pm (M o 1 i^ I-- •T< l^ ■* o •^ • •A^iand (M t~ tH X X d JO ijuai'^onf) CO X X I- X X XI r-l Ci -t< l^ o CI p T-H rH X CI rH rH <4H O Hi •*t^ O !M rH in -t> in o t^ IM X t- rH t^ •^ •asooniQ (N o r-i rH rH j-\ r-< ; [4 • iJ S H P Ch 00 —J c; lO X o CO !z: >-: c; C-. i^ CO X 1- -f < w^ •asojoni;' CO X CO rH CO ir CO O 1—1 »— < T— * rH rH r-^ i~^ rH Eh o !5 cj t— o •^ t^ T~i O X Ci r-H ^ •A:}iAUi" ?? o X C5 C5 o CO X CD iO U -*■ ogioodv>; P ^ p I-l P rH p iH p T-H p 1^ p rH n g H5 s ^ rH CO Ci CO rH m O •po^OB.qxa '.? To § CD Cl ■-3 in CD •:)U90 .laj »-H "l" CO o o M o •II01}\!A «4-t M o 174 z t- CO • -mn .lapun «aav CT' I-H ^ rH rH X CO rH cf ■I. q Ci d (!h n aj =; CI X CO X ir^ ■*l CI CI l~ ;5 M J 1919.] SUGAR CANE EXPERIMENTS. 141 The results from the plant canes in Field 1, St. Augustine, are given in Table IV. These canes were tested at the end of March and April when they were 16J and 17^ months old respectively. Generally the results show a substantial improvement in the quality of the juice when tested in April compared with the results obtained in March. The lower results obtained in April from Badilla and B. 14761 as also the verj' small improvement shown for B. 10650 is due to the fact that the stools selected for analysis remained in the field for seven days after they had been topped owing to an accident to the cane-mill. The juice had a decided acid reaction and the deterioration of the juice is further shown by the increase in the pei-centage of glucose and the decrease in the quotient of puritj'. It is probable that the same marked improve- ment would have been obtained for B. 10650 and B. 14761, under normal conditions, as shown for the other varities. The Badilla and H ? appear to have come to maturity by the end of March. These results confirm those obtained during the past two years viz. : that with few exceptions, plant canes do not come to maturity at St. Augustine before the month of April. The highest results were obtained from M. P. 55 a seedling from Mauritius, but this variety owes its position solely to the high tonnage of canes reaped per acre, for as will be seen in the table below, the quality of the juice is much inferior to that of any of the other varieties. The next best results were obtained from B. 14761, Ba. 6032, B. 3922, B. 6308, B. 156, B. 6388 and H. ? Eighteen varieties have given better results than the Bourbon and the average for the whole field was. 33"58 tons of cane per acre. 142 TBINIDAD AND TOBAGO BULLETIN. [XVIII. 3. s -J2 S ' -Ti O l^ r-t 1— i -- l~ V. M .^ >5 o ^'5' a) t— 1 c '^-, K o ^ a ■< o ;^< o H ^„ ui aso.iong asojong JO !JU9I^0nf) -tiox •osoon[i) •aso.io«y •xua •41100 .13 J •UOI4«A -i^juo .ioi>uii Bo.iy 5-1 'X, CO o 00 CT- .-I CO C-. CC 00 CO o Eh o -1' i? I- 1~ JO CO t~ Kg5 -r -f coco la X 1 c^; (Min «c cv -* (M 0^ 050 i^t^ :; X XX OCX X o; -f" X 00 X XX CO X XX t1 Ci S^ X X t- -*< CV X 10 O XI- >s -^ X C-. -^ X r; IZ iS (M 10 I- S5 X c; -f ci >S X -f »C •M CO r-^ -r *c r— ( r^ -f -f :r 1- i- X 7f X =-. p CO l-X I'-X r^x ? T1 ccc-. CO I - l~X 01- c. •-: 1,1, l-X ■ t^ CO «!0 ' ~ --I t- .^i 00 'P Ci I - X l~ I- s ^ » t:^ .-I ^ tS i~ X L^ CO X M c^i -f> C5 CO i~ o CO -js t^ c; -t< o •uoii'bs .13d _~ r-r- i^ * v= ?= ^?~ T ? == ?^ '."- 'P ~ I- •■:= -• asojDng I — ' '""' ""— """^ '^''^' '"''^^ """" ^^ ""^ -nox o?-j oorH t~^ T''?' 7^?° '?'•? '?'t' 9^?^ 00-r X O O "M O is C-1 I O 01 O C5 CO -n" -rC CO ib At< C5 XX ~— XX XX ~rv x~. XX XX xx ■asooniQ •asojong •xua •a^iabjS oijiDads ^b- •M l~ (M t^ 01 -* T— 1 T. CO o 1—1 C5 X CO l^OJ O Ol t=.o „. ^H 01 I- t~ t^ -T X Ol OI OIX t^l~ c o O »— f O IC .*.. — ^ — ^ - — ;: X — ^_ j^ ..^ r X O X .— .- CO t;~ •^ i — X X ■^ ^^ l~ o -I- -r ? 32 C-. CO CO X C• ^ t— O X CI ^ !M --1 1—1 CO 003 l--'.l COCO lO o w X 10 M O I- O Ol coco oin CO --; l-H I-H 1—1 ^- o •-r TT O ?, X 1-H oo 01 "^2 i-O -^ 1— ^H iS t~ t ~ -f (N-^ 0^ T)> CO s: X ? so ■^ ? •^f 00 CO Ol- ~— XX X J: i-t- -^ o o— i~t- Tj-Zi X r: — CI — — CI CI CI CI i-i— r-— 1 r-^i-i •p3^0T;a:^xa •!JU30 aaj •UOi:jBA Ci o COrt t^:C CO =■- 'T s; 1-i -!• o t - ■^ — ^ -(■ C-. ^^ ir^ o^ ir: =! — CO ^irj ^ o O —1 t^" ■— -p •— X X I- l^ t- X I - 1^ r: X X ri 1- t^ t-x l~ X / 1— • 1—1 _^ — • -- ^- 1— ( 7-^ 1—1 -:-, 1,1^ ^^ T-^ :_- COCJ t~o COf >- t - i-O C5 T-H -f o\ o -J- o vs ^ .— i i."^ CI CI i- X I, — -^ ^^ ■_; X — -— CO lO CO *o •^ -o CO I-H i!^Xi3 Japan Baayi d^ ^":^ X >o CI X X -r I- •O _3 »n — 144 T BIN ID AD AND TOBAGO BULLETIN. [XVII I. 3, p-l 8 o tn H 55 < O < I Eh •aoiuC in asojong •30lTip •sauBQ J8{ •uo^bS osoaong JO r^uei^on^ o o bD CS c Ph -uoN •asoonjf) •asojOTig •xug ■-f^lA^jS ogioadg •pa:>0Bj^x9 -jlino •UOIIBA .ispuii «aJY o o CO CO p eo I- I- CO OC oo oo CO CO co- co CO o o H CO o CO 00 00 CO CO lb 00 C-1 00 in CO (M p O CO a-. C5 0-. -o cc cc lo t^ -f CO CI C-l l-C^J 6o coco o o t~lp >S 00 in I- oo 00 CO o CM o o 00 o o CO — t-i cr. 00 OC (M O -9" lO O .-I o o - O &3 •90IU[ 111 asojong 1-5 * O Q Z --] I a ij n ■< C5 .© ■.CO aad asojong •A;und JO ;juai:jottf) CO CO 00 00 I- 53 CO (M CO CO in c-i in o CO o 00 I-l CO 00 t^ 05 »n CO © IM CO 00 o; o ?rj, o v? ?j y: ;o o * ?1 !M :o (M • Oi 00 S 00 CI C5 -UO\J 3 1-5 C5 r: a. ^ ^ ••^ ^ C CJ tf a> — (U > ^ o 'A <^ J^, 3> bO es S "J u asoonif) •Bsojong •\i.i{I CO «o o to ® CO o CO oo to 00 CO o 00 Ci «o eo CI 00 «o 00 00 m o CO C« CO 00 lO -- © ^ 00 00 00 © oo CO X 00 o © in CI in to oo r-i CI x- 00 © CI © CI 00 X © X X p •AJlA'B.lS ogioadg ■pa^0BJ!JX3 ■^ -^ C^ © l>» O CO c sO CO CI "* in ©_^ 6"* •* cf I- in ©" t-f -r aS'-ICO'*' — WCOi- «0 CO CJ CI 5 §*= 4f^<^ < to oo CO © M" CO Cl ^— ^ « in m © in ij CO r^ •n" CO ^ CO ^ pa CQ CO W K P5 r- CI CI P3 CO 1919. SUGAR CANE EXPERIMENTS. U7 c o ■/I a o 'v3 .—I 0) D <»1 50 O CO r- O 3 a o "3 C5 to aj 03 cc =':s 53^ 90 -O^ ^ g ■g Q) S J .id o --a) — CO - ^•_, o ■=« o " " o o O +a IK 2 CD 2 " 2 C -*= 9^:3 =^ Si i o p^ > C3 r^ :-r -iO > '^.^ CD =3 ^ C '^ c 3 p; o to cS O CO J-, 2 53 ^ 2 .-• . -^ -^^ - w-^ ^ — w if; _:: r^- 03 i— I OJ -" — o c ^ d to O ff ^ '^ ^ - O) OC ^ 31 - .Pi cc r- . •■'.—IT"-*-''-, O ;S — -^ b - £^ y ^ 2 ^ Cm 2 tC ;:^.^ -i .S rg 3 i "if ^ _ 2S S'; o-> ? o *3 o ^^ p^ p.^ ^.1 o -e3 £; "*"■ o CO -r^ '> o «a VI r- '/I ^ -t= a; C!i m ^> ' 'J '-a ^ 01 s o QJ cc ■+3 11 0) C) ^ >j o r^ H 3 o H -rJ '~^ s o •Jl o 1 ^ 3 >-5 CO ^ ■M,-H •30iuC til asojong •aomj;' •sauBQ •nonuS jad osojong n o o •A'^uud JO :juai:(onf) -5 ■jrang -uos^ •asoonifj •asciDTig ■xi.ia ogiDodg •]iiao .laj •llOI^B.V -1^110 japmi Ba.iY (M • "5 C-. ?1 ift .-H C5 CO t^ -^ SI lO J2 ^ Ci »< in J O t- eo in o rf 1-1 i-i r-( T-l CI 1—1 00 f t-l *n cc in CO — ^ t^ 01 — CO V3 X l~ CO 00 to (M r-\ «D »-1 t- .» O r-i CI 00 00 ""' o ^^ o "^ o ^ T) 00 '^ .— 1 ri "T t- T-^ _ 00 ' ' ^" "' T1 ^^ 00 oo t^ -^ O C<1 in, 5 1— t — ^H k— 4 f^ JW »!5 r- »-^ 8 ' o 148 TBINIDAD AND TOBAGO BULLETIN. [XVIII. 3. CO o o Eh Eh E-t "o J? -f ^ 1 -4^ 1 J2 rv. o tH s ti 1 C 05 1 r-i 1^ Aj 1^ iH Ah 1^ 1^ >H ^ C5 00 f i-'^ ^ ~ CO ce w X ~. CO ;i o IS w o CO CO t- cc o t^ lO ■* cc o o o c^. o c c; C". t— I CO r-j -^ o o '-C o t^ r- - OOOTf— I IS I— T i^ i^ oo L- i^ -^ r- cTi lO CO :c T— I lo cr CC l^ CO c-i CO' ■;i' CO c-i ^ I ~ M 7H IS X IX X ip -rf* r-H ci 03 yi -^ oo ip C] i I- lb i~ CO CO CO li'i i'o o c^ iss co »!- i-~ i^ -f t~ i-i c-i ~ Cj CO Cl I<1 Cl Tl '^^ d IM M 0-1 ^^ T— I r-* T-i 1— I I— I rH T— ( 1— I 1— I r^ to l^tCXCOCOCSi-llOl^'MiS-fl^inOnSi-^XmOCOlS C5 — C' CO -f O IS 3V. t^ ifl t^ X -P CO 'M -t< O — ■ lO ^ O O^ X OO c: p x c; t^ CO X X p iD 00 X c; >;- c: t- t^ ri t~ C O CI m .— IC-a^-r-1^^1— li— IrlOi— '>— Ir-lrHIMC^Ir— IrHi-H,— iCli— IrH J_| » » -< •w ^. B r-i'*^ w ■jr w C-l C-l iO l^ I- p p. !^.| O p. p p IS CO p p. r-l r- CO Ol t~ 1^ CO O i t^ .^ X O Ol 01 do X O CO -^ t^ QO 1-1 tr^ 1^1 i~ X (is c. c:o:xxci xxoxxx05c;C5XX05X05XX co 00t-C:Xl-— ':0!Mr-. X — iOCOCiiC1COOiCI-CO-*CO CC'lScrCliStCt-HiSO-^OOOOsrsXX'SXl-rHO 'COOi-IOCi-i^^^OOOOOOO^r-' ,_( OOOOCJX-l'iSCOlS"— C-l'^t^t^lNXm-fCOCOCCO 05t^ri.-li:D050CCt-~XCOOX1'X"i-IX CO C'C^-^r-Or-lr— ■ irHl-'OO'O'— It— I^Hi-^O^HO ,—1 •rt-l r- 01 1 I I-H r-i r-1 ir-l 01 ' I 1— I T-1 1— I J'l , CO -1- CO l^ X ce c: O C: — . -r I- -t- I- iS CO -f C-. C 1-- X Tf CO o e^'' X CO ^ c r-. ^ is i^ CI — . 01 1^ X iS -t< •-< I- CO M< cc to XXl-XI-l-XXXl-Xl~XXXl-l-Xt^Xt:-X t^ c o o o O' o c; o c- o o = o e o w o - ■_ p p '_■ cs p. 1-- p iS X ^r 7H X IS p. C5 Tf CO 1 s X I ~ -J: i -f I - -f CC t_- 01 p X p p p p ip 7-1 C5 s -i^ ^ p -f ^ iS _p ;s 09 CO 00 t^ •— ' IS o CO I- oa X CO c o 01 c c; ~ -T : X 1^ 01 CO t- CO X -r CO -r t- I- X IS iS -r ' Ca C — CO I 1 CO X i-H — CO t^ ~. X X ~. ! ■ iS -r 01 C CO : S X O IS > X 01 ~ l^ CM c c — I- c r-. is I- "■ IS IS .s ■ X IS X »S X I' ffH iM © o IS 05 O CI IN l- c CO CO" ce "-f t- IS X o o t~ ^ CO CO o ,_• 01 COC"- — — COCOr^COOlrH T— I GO -r tC ~ Qj c 1 01 CO CO . CO . o) -t 0-1 I- ?o CO x X 5 in » CO ■«■ CO ::: p4 M M K M K M M S W H i4 W M H W M ?; M H ffi W o O 1919.] SUGAB CANE EXPEIilMENTS. 149 fl =3 «« ^ o to ' t>D 5 n3 1) 03 O GO O o cc -*-=• O o3 CO -r-i r5 'ft P .ii,^ ;-< u DC „ Jl^ CD 0) Q c3 o tt) ^ S cS C c3 EH -a o -+3 03 '^ m 'a o cS > 03 CD t— t ^ to ry; CM J;^ C- " « '-S °o i^ • o .2 a) 3 M s ^ Ph CD G 'u O O aj b G o o3 cc o CD -^ ft^ CD CO ■73 CO ^, A o < a w tS «^ rj ^ ~» ^ CS! b03 l-H O c» 35 S •Jl :/! ^ "S 1 in 1—1 C35 m r— < -S 8 • '^ ^ c ^ 'rs ^ <« ^ ?; Wl, CO » S2 R Oh c:j >-5 •30111 C III eso.ions a o C5 ri -1 C-. - '-^ o .t J2 :5 p p O CO O 0» 10 (M_^iO rH CO^ co'r-Tio'i-^-H^o'iOio'm 1-1 1-1 1-1 .i^-^ rH o .0 >n CO 12 i- "^ -o -; «* CO t-C -f o -o -t> o t^ p -O lO ■■ 1-1 S -^ r-l ^ CO O ^ 1-. H ft :q p M :5 W a ft P5 150 o C) w s; o o < c o o » CO PQ < TBINIDAD AND TOBAGO BULLETIN. [XVIII. 3. cc ■« -t- O C a ^ -l-> (M o IM (M 00 O) ^ ac: < 2 ■X! m o s X T-t I rr '- *~ S^ 1-'. r^ "§ " %• -^ S a, "S ts s -a 5 (=) Qs {A O < W nt •ooinf oso.iong •aoiuf •KOUB^) JO :ni.>i^onf) C4H o 0) to cS -M c H O u (U ^ •osooni;) •oscioug •xug ■.{:)}AB.i5 oyioodc^ •:}iiao .laj •iioi:ji}A -i;|uo .lopim ojo.iy 5 C-. oD --I" c cc c o 00 -^■lr^ ..-; c; 'IJ S IC IC lO i~ -P ■^ T" ^■t (X CI 1^ p o [3 c— JO o i-^ ci t-i ci "^ Cl ;C' » C". C". CC »^ *^ w O L^ — ' w ci'io'c; clef co'co coco M in'co 00 >- o 00 CI I- in CI cc CM Clr^ •-T c; r: w o Lt CJ -f --I --J ~. ^ $2 c^ o C-. o ~. ~ i-r: r^ ~. --p CI i~ r-< CO - ■^ir;-roci-^i'*c• i^,^A-!A4i^^r-l'-<.--■- = — Or- 1- X -f CI u l~ I- CI Cl CO COX'.C'— ~XcO ^ oco CO '^ C: X CI ~f* •-' ■^ f^ '^ CI O '— C: X CO X ~ 'C '. C-. ci X CO vo -t< -r I- i~ic CO -f ^ 00 :^ CI CD :; ;r p -tH 00 ip IS p l_^ p O -Jf p i_0 ftO C5 p t: i~ i~ c: c: 00 i^ t- X o do I'c oo -r. t^ — "I— i—r-i— r-r-ir^C1 — .- r-l — " X-1• ir: CI c 1^ c: 05 1" i:r:'r-J cTi";' o O CI X C5 CI C C 1 ~ '" ' — CI O •-ico'xicoor". •— •.T'-' iico o rJO-f CICO'-l-rH'--l_:,COX 'T' ccci e^coi^ _?5 c:^ '^ eo CO I o O pq CQ i-- KM 1910.] SUGAR CANE EXfEUIMENTS 151 The averacje results of plant canes and first ra toons t'loni Fields 1 and 10, Yalsayn are given Table IX. Eight varieties have given better results as first ratoons than as plant canes ; with the exception of M. 905? all the varieties have done better than the Bourbon. The highest results were obtained from 13. 6308, B. 1:>6, Ba. G0J2, B. 347, B. -208, B. 4934, D. 109, D. 116, M. 1237, and Badilla, all of which have given an indicated yield of sucrose in the juice of over 3 tons per acre. Table X gives the average results for plant canes, first and second ratoons from Field 1, St. Augustine. The bast results were obtained from B. 208, B. 156, B. 147, D. 141, and T. 75 ; these have given an indicated sucrose in the juice of over three tons per acre for the three years average. With the exception of Badilla, H- 27, and B. 4578, the second ratoons gave better results than the first. Table IX. — Average Results of Plant Canes and First Ratoons. 1' celdd 1 and lU, Vulbuijn, Cane. Sucrose in Juice — Tons per Acre. Plant canes 1918, 19 months old. 1st Ratoons 1919, 12 months old. Average for 2 years. B. (i3()8 ]i. lofi Ba . G0.32 i:. 347 B. 208 B. 4934 D. 109 D. ik; *:.I. 1237 Ba dilla *st iped ■;;■ P. 5.") T. 202 B. 37('. B. G388 T. 75 *^\"hite Tanna B. N.H. 02(1) H V H. 227 B. 640(1 B. 3:i22 B. (5835 B. N'.H. 02(5) T. 39 H. 27 *B. 7482 Bourbon *M. 00 oa 3-73 4-54 3-87 3-78 3-99 2-9(; 3-72 3-98 3-27 311 2-72 2-73 4-0() 2-65 2 -04 2-70 2-39 2-88 2 -4.0 3-34 2-04 2-()0 2-31 2-52 2-15 2-25 112 216 1-59 4-00 2-75 2-99 2-97 271 3-63 2-69 2-22 2-92 2-98 2-85 2-79 1-.39 2-75 2-71 2-44 2-42 l-7. 504 4-08 1-64 2-04 2-79 D. 116 3-()4 1-87 2 -.59 2-70 B. 1753 3-30 2 13 2-03 2 09 T. 3(t 3-48 2-07 2-.")0 2-68 D. 3956 3-23 211 2-03 2-66 B. 3390 4-32 114 2-40 2-02 B. 7169 :V37 1-51 2-38 2-42 B. 376 2-77 1-76 270 2-41 T. 202 2-42 2-31 2-48 2-40 D. 2468 3 16 1-49 2-54 2-40 D. 306 3-74 1-16 215 235 Ba. 6032 2-48 1-94 2-58 2-33 Bourbon 3 25 170 2 04 2-33 D. 115 3-58 1-01 2-34 2-31 H. 27 3-17 1-96 1-81 • . • 2-31 B. 3412 3-52 1-01 2-40 .. 2-31 B. 16832 3-29 1-07 2-09 213 B. 4578 2-99 1-74 1-47 2-07 1919.\ 153 RAINFALL, SUGAR PRODUCTION AND PROGHOPPBR BLIGHT IN TRINIDAD. By C. B. Williams, M. A., F.E.S., Entomologist in Charge of Frogbopper Investigations. INTRODUCTION. The disease known as " Blight " or " Froghopper-blight " of Sugar Cane has been known in Trinidad for many years. The Froghopper {Tomasjois saccharina) was first mentioned in 1889 but, even before the ■connection between the disease and this insect was recognised, old descriptions of injury leave little doubt that similar conditions were present many years before. From the very earliest reports there has been a tendency to consider adverse weather conditions as one of the most important causes of blight ; both want of rain, and excessive rainfall being suggested by various writers. H. Cruger, in the first account of blight (written in 1863, published in 1892) considers one of the most important causes as " a want of rain at a certain period." .T. H. Hart in his " Report on Sugar Cane Bhght " 1890, says that the canes recovered on the advent of suitable weather. A.E. Collens in 1906, reporting on an outbreak at Harmony Hail, notes that " the dry season had been followed by heavy rains with rather long intervals of strong sun." G.T. Fenwick {Proc. Agr. Soc. Tdad d- Thgo. IX. 1909, p. 558) writes ^' the attacks, whether from insect or fungus pests, were usually noticed to follow periods of abnormality in the seasons and generally disappeared when weather conditions were again normal." P. L. Guppy in 1911 (BiiU. DepL Agr. X. 1911. p. 82) says "the extremely dry weather of this wet season has been particularly unfavourable to the growth of the cane and at the same time favourable to the rapid increase of the froghopper." F. W. Urich in 1913 [Circular No. 9, Board of Agr. p. 30) says that " a long and severe dry season generally tends to cause a severe out- break of froghoppers, whereas a m'ld one does not app'^av to produeo such large numbers." He gives figures of the rainfall at Woodford Lodge Estate showing that in 1908 and 1912, both years of severe blight, the dry season was long and severe. J. C. Kershaw, on the contrary, in 1914 (Bull. Dept. Agr. XIII. 1914. p. 48) says that " there is a common belief that in wet seasons the cane suffers less from froghoppers than in dry " but that " there is no real evidence that climatic conditions affected the incidence of froghoppers at all." 154 TBINIDAD AND TOBAGO BULLETIN. [XVIIL :i. It is the object of the present report to inquire more fully into this supposed relation, and to see how far the various statements are justified by the experience of a longer series of years. It is recognised that the rainfall may have effect in a number of different ways. Early rains in May will result in the broods being earlier ; a sudden, as opposed to a gradual, start of the wet season will cause the broods to be more distinct ; late rains in December and .January will produce a partial fourth brood and may cause many eggs to hatch that would otherwise have passed over till the following wet season. We are concerned here more particulai-ly with the total amount of '• blight " or " damage " in each year in relation to the rainfall. The records of previous observers have been freely used and their contribution is gratefully acknowledged. GENERAL RELATION BETWEEN RAINFALL AND CROP. The strength of a chain is limited by its weakest link ; in the same way the production of any crop on any particular piece of land is limited by the most unfavourable condition affecting that crop. This condition may be one of many— temperature — rainfall — wind- chemical condition of soil — physical condition of soil— drainage, &c. Whatever the limiting or determining factor may be — and it may be different in different places or even in the same place in different years — the yield of the crop will directly follow changes in the limiting factor. We should expect, then, to find the most distinct correlation between the sugar crop and rainfall in countries where the rainfall is low and has become a limiting factor. Such a condition is found, for example, in the island of St. Croix where the rainfall is seldom above 40 inches. Fig. 1 shows the close relation that exists between the crop and the rainfall for the years 1891 To! .10 L y s*- C roLx /tar-:' ?oooo. i5;ooo 4 10,000, Jooo" * ■ i Fig. 1. Fig. 1. Annual iaiufnll and sugar crop in St. Croix 1800- HO-J .sliowin- close (ic))L'nilMncc .if yield \!|>on i;iiiifall. 1919.] RAINFALL AND FROGHOPPER BLIGHT. 155 to 1902. Every change of rainfall is sseii to be reflected by a change in the crop. In Barbados whsre the rainfall is higher (40 to 80 inches) the correlation is less exact. Fig. 2 shows the rainfall and total sugar crop of the island from 1870 to 1894. It will Ije seen, however, that even (0 5b r 1 10 I ri <"• > . • • • • « ..Crtj) • T^m^all a«3 Sugar Crojj 'b?8"'k'2-^ 3^ irs ^ It-} -i -fj o •I k° 30 I 20 10 J2. S o o Fig. 2. Fig. 2. —Annual rainfall and sugar crop of Barbados 1870-1894 showing that the effect of rainfall on tho crop is most distinct i 1 dn- years. here, the rainfall becomes a limiting factor in those years in which it is unusually low. Thus the years 1882-3, lSS.5-6 and 1890-1, which were years of low rainfall are also characterised by a distinct drop in the sugar production. In Trinidad the correlation is still less marked (Fig. 3) for although the highest crops usually appear to have come in years of high total rainfall (1900-1, 190-3-6, 1916-17) yet years of low rainfall may produce quite good crops (1903-4, 1908-9, 1913-14) often indeed well above years of much higher rainfall. nrriYxiclo.c\ SuciarGroJj au^l7 j^ 70 a ifig. 3. . 3.— Annual rainfall and sugarcrop in Trinidad 19C0 -191S s'lowinj ab scuce of distinct relatio > between the two. 150 TBINIDAD AND TOBAGO BULLETIN. {XVIII. 3. The lack of relation between the total rainfall and the cane crop is shown still more distinctly if we compare the rainfall on an individual estate for a number of years with the yield psr acre on I "A i J' ••• .•• t309(, "i-^' '7*8' ^7 yfa *rii tin ii-o jj^t ' /3-^ in^ ' JfTT Fig. 4. Fig. 4.— Annual rainfall and yield per acre on a Trinidad sugar estate, showing aVjsence of distinct relation between the two. the same estate for the corresponding year (Fig. 4). It will be seen that the highest yields per acre between 1905 and ]918 on this particular estate were obtained in years of low total rainfall ^903- 9, 1914-15). It is worthy of notice in this connection that the total rainfall of Trinidad is no greater than that of I'mrbados, yet in the latter island a low rainfall almost invariably produces a small crop. The explanation is found in the f.ict that, in spite of similar rainfall, Barbados is very much drier both in soil and atmosphere than Trinidad. The porous coral soil and rock in the former island allows the moisture to drain away more rapidly than do the heavier soils of the Trinidad canefields ; and the more constant sea breezes and the lack of forest areas in Barbados prevent the formation of a stagnant moisture-laden atmosphere frequent over the canefields in Trinidad, where even in the middle of the dry season the cane plants are dripping with dew every morn- ing. A Trinidad sugar estate with a rainfall of fifty inches in considerably moister, in practice, than a Barbados estate with the same rainfall. In Trinidad, therefore, it appears that the total rainfall during the year is not an important determining factor in the sugar crop of the island. Even in dry years there is sufficient moisture present to produce a good crop, provided only that it is properly distiibv;ted throughout the year. The years of wide spread blight during this period were 1906-7, 1907-8, 1911-12, 1912-13 and 1917-18. It will be fcen also that these are not marked by any unusual excess or deficiency in the total rainfall, but may be yeai-s of high or low precipitation. 1919. \ BAINFALL AND FliOGHOPPEE BLIGHT. 15T DISTRIBUTION OF RAINFALL DURING THE YEAR. Even in countries like Trinidad, in which, as has been shown, the total rainfall during the year is not a limiting factor of the crop,, that rainfall may be so distributed that there may be an excess at one period of the year and a deficiency at another. The normal seasons in Trinidad consist of a dry season lasting usually from January to the middle of May, during which the rainfall is generally below three inches per month, and a wet season from June * .5 4.1 5 <5 . TB1NIDAD^'RA\NFAU " 18 62. ?_I9JI^. |u fib Hcu/ Q»>- I»Uy iw>t jul^ C^ S||, Qd- K«i T5S^ Fig. 5. Fig. 5. —Monthly rainfall, Trinidad Botanic Gardens, average of fifty-three j-ears. to December in which the rainfall is usually over five inches per month.. Fig. 5 shows the average monthly rainfall at the Botanic Gardens,, and St. Clair Experiment Station, Poi-t-of-Spain, for fifty-three years continuous observation. W There is however one feature that is not so distinctly emphasised by the average curve as in reality. In nearly every year a dry period of longer or shorter duration occurs during August, September or October and is known locally as the " Indian Summer." An examination of the monthly records averaged in the above figures shows that this drop in the rainfall was distinct in about 35 out of the 53 years under consi- deration, the rainfall being below five inches four times in August, eight times in September and thirteen times in October. This Indian Summer is one of the most important features of the rain distribution and has, as will be shown, a marked effect on the sugar crop and particularly on the prevalence of blight. Owing however (1.) 1852 to 1899 at tlie Royal Botanic Gardens, and 1900 onwards at the closely adjacent St. Clair Experiment Station. 158 TRINIDAD AND TOBAGO BULLETIN. \XVIIL ■{. to it occurring soiuetimes in one month and sometimes in anotlier its effect is almost eliminated in the process of averaging. It will be seen raore distinctly in the graphs M'hich follow, particularly in Figs. 7, 9, -and 11. The cane in Trinidad is usually planted from August to November <" wet season plants ") or during the drj' season (" crop plants'") and is •cut during the dry season of the following year. " Plant canes " (first cutting) have about eighteen months growth and " ratoon canes " (second and third crops) have twelve months growth. The crop is therefore liable to be affected by the rainfall during the . (I.) Dry season usually longer and more severe (191G exception- ally long and dry). January usually dr^-. (•2.) -luly rainfall above 9'7 inches in all cases except o e(nni, which had a wet June). Cd.) Indian Summer distinct. Rainfall five inches or below in four years in September, and in five years in October. Never above five inches in both of these two months. Particularly low in October. 0.1 the whole the years of wide spread blight are years of extreme •contrast in rainfall characterised by alternations of excessively wet and dry weather. In order to confirm the above results a comparison has next bean made between tlie rainf ill o.i four estates during 1916-17 when the ■damage due to blight w.is ahnoit negligible (Fig. 8) and the rainfall 1919.] RAINFALL AND FHOLiHOPPER BLIGHT. 159 on the same four estates iu the following year when the damage "was very severe (Fig. 9). Tt will be seen that the following points are again emphasised : — Good Year, 1916 (Fig. 8). (1.) Dr3' season not severe. January wet. (2.) July unusually dry. (3.) Indian Summer distinct, but early and not severe. Bad Year 1917 (Fig. 9). (1.) Dry season long (Decembsr to April) and rather severe. (2.) July unusually wet. (3.) Indian Summer later and unusually severe. Once more the wide spread blight is associated with alternations of wet and dry weather and particularly with a late severe Indian Summer. The two estates on which the rainfall remained low during November and December (Fig. 9) are both in the Southern half of the island and in both these the persistence of the damage after the froghopper had i. u- P~M s o Oi) 5 S o s o S — 2 "5 ^2 o 166 TBINIDAD AND TOBAGO BULLETIN. [XVIIL 3. DISCUSSION. It will be seen that there is strong evidence that blight is more wide-spread in years or localities with unusual alternations of wet and dry periods and particularly when the Indian Summer dry period in September or October is well uiiirked. The relation of this fact to the general problem of understanding and controlling blight will be dealt with more fully later in a report which will take into consideration other associated conditions. The object of the present report is chiefly to give accurate data for future discussion. The follow'ing suggestions however, arise from a study of this relation. The critical period at which the canes seem to need moisture to prevent blight is in September or October. This is in most years just after the second brood of froglioppcrs. Drought at this time cannot aiTect the number of froglioppers of the earlier broods. It may affect the numbers of the third brood (possibly by preventing the spread of tlie green muscardine fungus) and so increase the damage later in the year. But probably the most important effect is that it prevents the recovery of the canes to wdiich damage has been done by the first two broods, and in those frequent cases where root fungi are also present, it works on an already diseased root system and causes the more or less complete drying up of the canes. The fact that this important determining condition occurs after the second brood is further confirmation of the position to which we are driven by other considerations also — namely, tliat the actual number of froglioppers present in afield, although naturally not to be ignored, is often of less practical importance than the general ability of the field of canes to tvitlistand the damage. In a previous report on the i-elafcion of Uoot Fungi to Blight {Bull. Dept.Agr. XVIII. 1919. p. 52-6) attention has been drawn to the same point and figures have been given showing the number of frog- hoppers that may be present in a field without causing permanent injury, and also showing that many fields have been destroyed with but a small proportion of this number. It may be argued that the rainfall is a condition over which the planter has no control. This is true of the actual rain wliicli reaches the ground, but the jn-oportion of this which becomes available to the \}\a.xxi depends very largely on agricultural operations. We have seen that low rainfall, and to a less extent high rainfall, are both conducive to blight. There is one agricultural process which will reduce both evils and that is Drainage. Good drainage carries off surplus water in time of floods and also (and this effect is less generally realised) provides more available water in time of drought. Drainage lowers the water level in the soil, and thereby makes a deeper layer of the soil available for the root system of the plant, from which more moisture can be extracted in time of drought. i 1919.1 RAINFALL AND FliOGHOPFEE BLIGHT. 167 It is common knowledge that plants in a water-logged soil are the first to suffer from a dry spell, for although the moisture may be present only a few inches away, the root s.vstem of the plant, confined by lack of air to the top layer of the soil, has not enough reserve strength to withstand the sudden adverse conditions and cannot reach the necessary moisture. SUMMARY. (1.) Alternation of wet and dry periods daring the growth of the sugar cane is shown to be an important factor in determining tlie prevalence of " blight." (2.) A long dry season followed by unusually heavy rains in June oi- July, is frequently connected with wide-spread blight. (3.) The most important climatic condition however, appears to be the severity of the " Indian Summer," a dry period in September or October. A severe Indian Summer is a general condition both of localities damaged by blight in one year and of years of wide-spread blight in one locality. (4.) Blight could be reduced, irrespective of its first cause, by getting the field in a condition to lessen the effects of excessive moisture and drought. (5.) Better drainage is the obvious agricultural method that will help to bring about these conditions. August 1919. 168 TBINIDAU AND TUB AGO BULLETIN. [XVIIL FOOD CROPS. EXPERIMENTS ON YAM CQLTIVATION 1918-19. r._v Joseph de Verteuil, F.I.C, F.C.S. Superintendent of Field Experiments and L. A. Brunton, Assistant Superintendent of Field Experiments. During the season of 1918-19, the previous year's experiments on yam cultivation at St. Augustine Experiment Station were repeated and two additional experiments added viz :— (a) staking the vine versus non-staking and (6) different size of plants. The results obtained were as follows. Trenches and holes were dug eighteen inches deep and half the width of the distances apart. For example trenches four and three feet apart were dug two feet and eighteen inches wide respectively; holes four feet by three feet and four feet by two feet were dug two feet by eighteen inches and two feet by one foot wide. The weight of the " plants " was approximately a quarter of a pound, unless otherwise specified. The plants were put into the ground between June 10 and 14, 1918, and reaped between February 17 and March 20, 1919, i.e., eight to nine months later. All the experiments were made with the Barbados Lisbon varietv and the results given are the average of duplicate plots. V.AUIETIES. Three varieties, tlie 1 Barbados Lisbon, Horn and Red yams were tried on duplicate plots. The following results were obtained : — Area jilaiited. Per acre. Variety. Yield. Value of crop @ 8c. a lb. 1 Lisbon Eed Horn Sq. ft. 450 450 45 J Tons. 15-25 9-33 4-67 S c. 1.024.80 626.97 313.82 The yield of tlic Horn yam is disappointing and practically ten tons less per acre than that of the previous year, whereas the yield from the Lisbon and Red yams was three and two and a half tons less respec- tivelv. The Lisbon has again proved tlie most prolific yielder, having given 5-8S tons per acre more than the Red yam. SELECTION OF PLA^NTS. The experiment to ascertain whether it \\as preferable to use the top, centre or bottom portions of the tub-rs for planting purposes was .again carried out. 1919.] EXPERIMENTS ON YAM CULTIVATION. 169 The plants were put in prepai-ed holes, three feet by three apart with the following results : — Description. Area planted. Yield per acre. Top Centre Bottom 450 450 450 11-32 11-15 12-01 • As in the previous year the above results show that the difference is very small and within the limits of experimental error; it can be safely concluded therefore that there is no special advantage in selecting any special part of the tubers for planting. SIZE OF PLANTS. With a view of ascertaining the correctness of the statement made by several interested in yam cultivation " that a large plant gives a larger yield than a small plant " the following experiment was carried out. Holes were dug three feet apart, eighteen inches deep and filled in the usual way. Duplicate plots were planted with plants a quarter, a half and one pound each respectively and the following results were obtained : — Size of plants. Area planted. Per acre. Yield. Cost of cultiva- tion plants and reaping. Net Profit. One-quarter pound ... One-half pound One pound Sq. feet. 450 450 450 Tons. 13-26 1-2-23 13-35 » c. 252.15 288.45 361.05 $ c. 638.92 533.41 536.07 The results are not conclusive as far as the yield is concerned, but they show that there is no advantage to be gained in using larger size plants than a quarter of a pound. The extra value of the half and one pound plants was ?i36.30 and 1108.90 p3r acre respectively. METHOD OF PLANTING Several points arise as regards the method of planting such as : — (1.) Is it more profitable to plant in holes or in trenches ? (2.) What is the best planting distance ? (3.) Is it necessary to have large holes filled with trash or manure? (4.) Is there any advantage in staking the vine? For theae experiments trenches were dug four and three feet apart and planted at distances of one foot, eighteen inches, two and three feet apart respectively. Holes were dug four feet by three feet, four 170 T BIN ID AD AND TOBAGO BULLETIN. [XVIIL 3.. feet by two feet, three feet by three feet, and three feet by two feet respectively. Another set of holes were dug two feet by eighteen mches wide and eighteen inches square but only eight inches deep at a distance of four feet by three feet and three feet by three feet apart ; trash and manure were applied to one-half of these holes as is usually done, whereas no trash or manure was put in the others which were simply refilled with loose earth from around and the soil drawn up in a hill over the holes. The results obtained are given below ; — o c c3 v S-t < Per acre. cS > a-. bD Treatment. ulti ant pin oJ o ri; :S ccr , ft 0- o •*- '^ i^ 2 Cost c tion, and P4 5 (5 7 8 9 10 U 12 IS U 1,5 Sq. ft. 560 oGO 420 420 nou !);io 1 ,201) 1,200 1 ,2U0 1,200 1,21)0 OiiO 900 4r>o 450 Holes 8 inches deep 4 ft. x 3 ft. wi trash or manure Holes 8 inches deep 4 ft. x 3 ft. trash and manure Holes 8 inches deep 3 ft. x 3 ft. wi trash or manure Holes 8 inches deep 2 ft. x ?, ft. trasli and manure Holes 18 inches deep 3 ft. x 2 ft. Holes IS inches deep 3 ft. x 3 ft. Holes 18 inches deep 4 ft. x 2 ft. Holes IS inches deep 4 ft. x 3 ft. Trenches 4 ft. apart planted 18 apart Trenches 4 ft. apart planted 2 ft. Trenches 4 ft. apart planted 3 ft. Trenches 3 ft. apart "planted IS apart Trenches 3 ft. apart i)lauted 1 ft. Trenches 3 ft. apart plantel 1 ft. unstaked Trenches 3 ft. apart plaute.l 18 apart unstaked Tons. ithout 6-94 . with 8-47 itliont D-49 . with 10-18 14-15 ...1 14 -511 9 -.32 9 67 inches 12 05 apart 10-31 apart 8-15 inches 14 -(54 apart 15 -.32 apart 16-03 inches ... 10-58 $ c. 158 58 179 87 187 03 $ c. 307 79 389 31 450 70 211 81 472 29 .308 44 642 44 2.')2 15 726 28; •279 68 346 62 ■228 27 421 55 303 01 506 75 2SS 15 406 70 273 02 274 66 3.36 31 .647 50 376 29 65 J 21 337 83 7.30 39 297 So 413 13 Although the soil at St. Augustine is a faily loose sandy loam it was found last yea-r moi-o profitable to have deep holes i.e. eighteen inches than shallow holes i.e. eight inches deep, notwithstanding the higher cost of preparing the deep holes. The experiment was repeated this year and similar results were obtained as can be seen by comparing the results of plots 1 and 2 with those of plot 8, and plots 3 and 4 with plot 6. Deep holes four feet by three feet and three feet by three feet gave a net profit of $421-55 and $7-26-23 per acre against $389-31 and 1472-29 respectively from the shallow holes. It will also be seen that it is more profitable to fill the holes with trash and manure, as not only has a larger yield b2en obtained but the value of the increased crop is more than sufficient to pay for extra cost of procuring and filling the holes- with trash and manure, vide plots 1 a id 2, 3 and 4. 1910.] EXPERIMENTS ON YAM CULTIVATION. 171 As regards the planting distance the results this year as last show that a lai-ger yield is obtained with close planting. Holes four feet by two feet and four feet by three feet gave yields of 9-32 and 9-67 tons as against 14-15 and 14-56 tons per acre from holes three feet by two feet and three by three feet respectively ; a larger profit per acre has also been obtained from the closer planting, similarly the yield from trenches four feet apart planted at distances of three, two and one and a half feet was 8-15, 10-34 and 12-05 tons as against 14-61 and 15-32 tons per acre from trenches three feet apart planted at distances of one foot and eighteen inches apart. It should be mentioned however, that it has- been found awkward to make holes three feet, by two feet and four feet by two feet apart, the nearest convenient distance at which these can be made is three feet by three feet, moreover it is with holes at this distance that the best results have been obtained. The best distance for trenches is three feet apart and the plants may be put at two, one and a half and even one foot apart. The extra value of the plants and planting one foot apart in trenches three feet apart is 539 38 more than when the plants are put in eighteen inches apart and an increased yield of 12 cwt. per acre would be required to cover this extra cost. The question as to whether trenching is more profitable than holing is not so easily answered. Trenching is more expensive thin holing but as it permits of closer planting, a higher yield is usually obtained vide plots 12 and 13 as compared with plots 5 and 6, also plots 9, 10 and 11 compared with plots 7 and 8. With trenching the land is better prepared for subsequent crops, especially if the untrenched portion of the first year is worked up for the second year. Holes three feet by two feet and three feet by three feet gave a profit of $642 44 and $726 28 per acre respectively ; trenches three feet apart planted at distances of one foot and eighteen inches gave a profit of $653 21 and 5647 50 per acre respectively. The usual practice in Trinidad is to stake the yam vines after they have grown from three to four feet long and the opinion has been expressed by several that staking is essential to obtain a large crop, the idea being that with our heavy rainfall and damp climate the vines would rot especially if injured when weeding or moulding the plants. With the object of ascertaining the correctness of this opinion two plots have been trie 1 this year without staking in trenches three feet apart planted at distances of one foot and eighteen inches. The results are shown under plots 14 and 15 as compared with plots 12 and 13 where the vines were staked. The uiistaked plots have given a yield of 16-03 and 10-58 tons as against 15-32 and 14-64 tons per acre from the staked plots. Although the results of this first experiment are not conclusive a higher yield having been obtained in one plot from the unstaked and in the other from the staked plot— they tend to show that as large a yield may be obtained without staking as from staking the vines. As "the cost of staking is by no means negligible it may be found in subsequent experiments to hi more profitable to dispense with staking. 172 TRINIDAD AND TOBAGO BULLETIN. \ XVIII. 3. AVERAGE RETUENS PER ACRE. The total area under yam cultivation at St. Augustine Experiment Station during 1918 was 20,785 sq. ft. or nearly half an acre, from which 11,613 lb. of yams were reaped i.e. 10-86 tons per acre. The value of the crop at three cents per pound wox-ks out at $730.14 and the total cost of cultivation including the purchase of plants was $267.83 leaving a profit of S462.31 per acre. The cost of cultivation may appear somewhat high but it must be borne in mind that it is the average for several small plots under experiment, which naturally cost more than under ordinarv conditions. i 19L9.'\ RAINFALL BE TURN METEOROLOGY. 175 RAINFALL RETURNS. -JULY TO SEPTEMBER, 1919. Stations. North - irf»t Did r k-t. St. Clair — Royal Botanic Gardens Port-of-Spain — Colonial Hospital ,, Royal Gaol... ,, Constabulary Headquarters St. Ann's — Reservoir Maraval — ,, ,, Constabulary Station Diego Martin — Constabulary Station ... ,, "Waterworks ... ,, River estate ... Fort George Signal Station ... North Post Carenage Constabulary Station Carrera Islam! Convict Depot C'hacachacare Lighthouse Santa Cruz — Maracas District. Santa Cruz — Constabulary Station St. .Tosepli — Government Farm ,, Constabularj- Station Tunapuna — St. Augustine estate Maracas — Government School ,, Ortinola estate ... ,, San Jose estate ... Cauia — "Wardour estate West Central District. Caroni — Frederick estate Chaguanas — Constabulary Station ,, "Woodford Lodge estate Carapichaima — "Waterloo estate ,, McBean Cacao estate ,, Friendship Hall estate... Couva — Exchange estate ,, Brechin Castle estate ,, Perseverance ,, ,, Camden ,, Milton ,, Spring ,, Constabulary Station ,, Esperanza estate Montscrrat District. Brasso-Piedra — Mamoral estate ,, La jMatiana estate Montserrat — Constabulary Station Brafso — La "^^ega estate Ainma District. Arima — "Warden's Office ,, Torrecilla estate ,, "Verdant Vale estate San Rafael— Constabulary Station Guanapo — Tali)aro estate ,, El Quemrdo Estate Tamana— Sta. Marta estate ... ,, La Carona estate ... ' ... San Fernando dt _FrincesToum District. Claxt oil's Bay — Forres Park estate Pointe-a-Pierre — Bonne Aventure estate ,, Concord estate ,, Plein Palais estate Naparima — Picton estate ,, Usine St. Madeleine estate ... ,, La Fortunee estate ,, Tarouba estate "Union Hall estate +» 1- CD i. igus h^ < m J3 +3 rH Ins. 5-17 4-07 4-80 8-29 8-13 5-39 6-32 4-97 G-07 5-84 .5-36 4-69 7-05 2-79 5-12 6-08 5-55 5-32 5-59 6-23 554 6 -69 6-98 8-37 7-07 6-09 8-26 7-43 7-98 7-29 10-08 8-07 9-99 6-39 10-64 7-18 10-12 8-89 7-16 9-08 11-12 12-18 9-87 11-11 9-75 11-06 12-03 12-15 4-28 5-57 5-07 3-93 4-34 6-62 4-5S 4 07 4-83 Ins. 6-82 419 6-24 9-14 8-27 9-19 12-83 14-72 10-77 11-25 6-05 n -19 6-41 3-33 7-66 12-82 9-34 7-78 8-16 11-06 7-96 9-68 7-83 6-78 7-20 6-75 6 03 6-67 6-74 4-04 6-88 3-22 9-07 6-65 4-61 9-06 11-75 10-02 7-11 9-90 10 -36 13-16 12-09 10-86 10-49 11-93 14-80 12-96 7-40 G-84 6-51 7-27 11-96 10-15 6-47 9-16 9-68 Ins. 7-96 3-93 7-11 8-65 8-58 6-57 6-24 8-13 6-57 6-63 11-03 4-34 8-97 2-19 5-84 4-69 5-07 4-61 4-01 4-77 4-59 3-50 3-39 6-73 3-50 200 8-73 4-10 4-09 4-27 5-51 5-71 4-59 5-47 6-03 4-24 7 03 6-76 4-80 6-21 4-41 6-76 9-05 6-20 5-28 6-76 8-62 7-00 2-98 2-12 2-lS 2-75 5-14 3-49 3-46 2-89 4 05 Ins. 34-30 25-18 33-28 30-63 40-51 34-42 42-10 47-71 40-.O8 40-20 , 37-73 I 33-41 39 -.57 14-90 ■ 31-74 43-33 1 36-75 26-64 33-44 41-86 35-00 39-03 33-21 45-45 36-09 34-07 43-09 37-52 .37-68 32-46 40-87 32-43 43'-.37 38-05 41-62 36-11 56-82 54-42 42-24 51-13 46-39 0* -.57 55 •51! 59-61 54-67 59 •71 71 -29 6404 29 -42 29 52 28 97 30 78 41 05 34 77 28 66 29 30 33-44 Ins. 4611 37-13 42-65 35 -.39 61-15 .53-64 57-05 64-59 53 -.56 54-43 50-56 .5.5-69 15-60 39-78 61-75 44 -.30 35-41 42-9-3 55 -61 47-80 46-93 47-88 42-53 41-68 49-40 45-79 36-10 43-87 40-15 46-87 44-05 39-26 38-84 62-31 58-85 49-98 58-00 60-24 69-30 50-76 63-53 66-43 72-10 78-10 68-98 39- 14 48-09 51-88 43-48 44-03 42-61 35-70 .32-06 42-16 174 TBINIDAD AND TOBAGO BULLETIN. [XVIIL 3.'19.] EAINFALL RETURNS-JULY TO SEPT., 1919— Contincki.. Stations. 1-5 3 02 4^^ .S'an Fernando and Princes Toion District.— (Contd.) Naparima — Palmiste estate ,, Lewisville House ,, Hermitage estate ,, Petit Morne estate Princes Town— Craignish estate ,, Cedar Hill estate ,, Williamsville estate ,, Esmeralda estate ,, New Grant estate ,, Constabularj' Station ,, Hindustan estate ,, La Retraite estate ,, Malgrctonte estate Friendship & Ben Lomond estates Los Naranjos estate Poole — El Itosario estate South-iveat District. Oropuche — Constabulary Station ,, Pluck estate Siparia — Constabulary Station ,, Alta Gracia estate Ouapo — Adventure estate ]'oint Fortin— Constabulary Station Erin — La Ressource estate La Union estate Industry estate Cedros — La Retraite estate ,, Beaulieu estate ,, Perseverance estate ,, St. Marie estate „ Constalnilary Station ,, St. Quintin estate Icacos —Constance estate Irois — Government School South Coast. Moiuga — Constabulary Station £ast Coast. Matura— La.Juanita estate Manzanilla— Constaljulary Station ,, Indrasan estate Sangre Grande — New Lands estate ,, Ilvasdale estate ,, Grosvenor estate ,, El Reoindo estate ,, San Francisco estate Mayaro— Constabularj' Station North Coast. Blanchisseuse — Constabulary Station ... Grande Riviere — Jlon Plaisir estat? Toco — Aragua House ,, Constabulary Station Point Galera — Light House Tobayo. Tobago— Hermitage estate King's ];ay „ Roxburgh ,, Luro estate Botanic Station <;ovenimeut Farm T.,owland.~ estate J'r'endship ,, Riversdale ,, Bon Accord ,, Ins. 4-96 070 4 -.51 5-03 .5 -.55 .0-06 G-01 7-78 6-04 rr-ir) 5 ■2.'? 7 •46 5-14 (i-94 5-88 1-71 4-j« 4 -.50 0-79 .3-99 (;-9(3 2-21 .3-97 4-70 8-79 4-82 504 6 -69 5-8:3 5-14 7-89 5-48 f)-55 5-90 9 14 12-00 12-05 11-73 10-03 11-90 5-47 Ins. 11-31 9-69 10-43 9-00 7-10 9-73 7-24 11-1.4 9-04 6-07 7-33 10-81 8-22 9-49 12-34 3-93 7-02 9-07 10-11 5-55 8-95 6-08 8-78 9-77 9-87 6-35 7-35 7-84 7-60 9-05 5-29 8-87 9-70 17-03 18-87 19-70 14-52 17-10 16-13 17-62 9-25 7 -.38 I 10-58 9-74 20-08 7-02 6-94 7-93 7 -.32 9-51 8-53 0-22 15-49 8-16 Ins. 5-54 2-54 4-98 4-27 4-14 3-91 3-80 4-21 4-91 2-75 3-49 0-48 3-36 5-12 5-11 1-75 3-14 2-50 4-06 4-21 5-49 1 -83 3-19 2-28 5-04 1-14 2-24 2-61 2-95 2-08 5-97 5-00 8-11 4-47 0-43 5 08 0-72 5-92 7-40 4-90 4-90 10 12 8-45 0-38 16-12 i 12-08 10-34 ! 8-50 10-15 10-.59 I 8-02 7-50 0-78 5-72 5-14 j 10-29 i 6-58 Ins. 42-34 41-41 45-31) 35-20 38-51 39-79 .38-01 00-04 45-19 30-09 3.-58 .55-31 33-25 48-70 47-24 15-00 35-20 30-00 41-44 28 -.52 41-76 31-96 32-34 45-40 31-97 33-55 30 -.-.2 .35-73 35-50 42-41 43-14 65-70 57-41 65-90 65-36 07-70 59-42 70-07 41-40 47-27 70-11 53-31 42-17 65 14 53-92 57-74 41-01 33-01 .33-46 Ins. 48-11 .52-01 42-36 37-93 52-2'.) 48-50 50 -9; I 03-(i.S 01-29 39-14 48 O:) 77-5:; 55-53 52-0'; 48-92 OO-9.S 48-29 52-15 .57-91 45-33 .52-49 32-76 37-39 41-44 51-63 37-97 10 •.'51 .37-48 38-32 101-95 44-09 42-91 76-60 70-02 74-7r, 77-89 75-04 7006 07-21 72-00 59-85 0(i-41 78-79 02-77 55-11 48 -.31 .58-12 92-42 51-90 30-61 4i'-i9 49-05 (Bulletin, Dcpt. Agriculture, T'd'id ,(: Thyo., Vol. XVIII. pp. 113-174. LssucdNov. 19 '19). CONTENTS. Fruit : Avocado in Trinidad and Tobago. W. G. Freeman Budding the Avocado. E. 0. Williams Insects Affecting the Avocado. F. W. Urich ... Fungous Diseases of the Avocado. J. B. Borer... Composition of Trinidad Avocados. H. S. Shreivsburtj Page. 113 125 129 132 134 Sugar: Experiments, 1917-19. — Trinidad Seedlings and Tests of Varieties. J. de Verteuil ... ... ... 136 Rainfall, Sugar Production and Froghoppev P.light. C. B. Williams ... ..." ... ... ... 153 Food Crops : Experiments in Yam Cultivation 1918-19. J. de Verteuil and L. A. Br union 168 Meteorology : Rainfall Returns— July to September, 1919 173 Part 4.] 1919. [Vol. XVIII. BULLETIN OF THE DEPASTMENT OF AGEICULTUEE, TEINIDAD & TOBAGO. Issued by the Department and Board of Agriculture, i^fJlS^K Editorial Committee. "W. G. Freeman, B.Sc. A.R.C.S., F.L.S., Director of Agriculture. F. W. Urich, F.E.S., C.M.Z.S., Entomologist, Board of Agriculttire. J. DE V-ERTEUIL, F.I.C., Y.G.S. , Superintendent of Field Experiments. Editor : W. G. Freeman. TRINIDAD : Printed AT the Government Printing Office, Port-of- Spain. Price : Si;s: Pence. J Ill, DEPARTMENT OF AORIOULTURE. Head Office. Director W. G. Freeman, B.Sc. (Lond.), A.R.C.S.,F.L.S. Assista7it Director {Acting) and _ I j. de Verteuil,F.LC.,F.C.S. Snperxntendent of F%eldExper%ments \ Asst. Superintendent, Field Experiments L. A. Brunton. Officer in Charge of Special Investigations. ..A-B. Collens, F.I.C, F.C.S.* Chief Clerk Jos. E. Seheolt. Clerhs ..M. Dhein, A. Hosein. Botanical Department. Government Botanist W. G. Freeman, B.Sc, (Lond.), A.R.C.S.,F.L.S. Curator, Royal Botanic Gardens, dc ~ Horticulturist andAsst. Botanist W. E. Broadway. Officer in Charge of Botanic Station, Tobago R. J. Link. Clerk F. Chookolingo. Herbarium Assistant— Miss P.McLban. Overseer (Trinidad)...!. Pinder. Foreman (Tobago) J. Blackman. Government Laboratory- Government Analyst (Acting) ..H. S. Shrewsbury, F.I.C, F.C.S. (J. DE Verteuil, F.I.C, F.C.S. Assistant Analysts -^^^ -g_ Collens, F.I.C, F.C.S.* Clerical Assistant S. M. Carrmuddeen, Government Farms. Manager J. McInroy. Manager (Tobago) R. J. Link. Overseer and Clerk (Trinidad) St. Augustine Estate. E Manager J- McInroy. K. Overseer H. Lyndon Kerr. Clerk A. P. Daly. I' River Estate. Superintendent L- Seheult, B. Sc.,(Edin.) 'Manage, R- O'Connor. i «^ ' ^ Acting temporarily as Government Chemist and Superintendent of Agricultui-e for the Leeward Islands. Froghopper Investigations. Special Appointment. C B. Williams, M.A., (Camb.) F.E.S. ] V' DEPARTMENT OF AGRICULTURE. Agricultural Credit Societies under Ordinance No. 30, 1915. Registrar W. G. Freeman, Director Inspector Jos. E. Seheult. Eegistered Societies. Trinidad Diego Mai-tin Lothians Malgretout ... Petit Morne... Union Hall ... Malgretout East Indian Picton Petit Morne (Palmyra) ... Tarouba (Ne Plus Ultra) ' ... Union- Marabella Hanuony Hall Williamsville East Indian Indian "Walk Williamsville, West Indian Plein Palais Lengua Tobafjo. Pembroke ... ... ... Scarborough Delaford Mason Hall... Moriah Charlotteville of Agriculture. Date of Begistration. , October 12, 1916. 1919. 1919. 1919. 1919. 1919. 1919. 1919. 1919. 1919. 1919. 1919. 1919. 1919. 1919. 1919. April 4 April 30 April 30 April oO May 26 May 30 June 13 June 13 July 10 July 10 July 10 August 19 September 11 ■November 9 November 9 June IB April 11 August 26 December 16 December 16 February 1917. 1918. 1918. 1918. 1918. 4, 1919. Plant Protection Ordinance. Chief Inspector (Acting) W. E F. W Inspectors . Assistant Inspectors. Broadway. Urich. R. 0. Williams. H. Meaden. L. A. Brunton. J. A. PiNDER. J. Blackman. R. H. Leacock Alfred H. Pena (Tempyj. Reference Library. This Library can be consulted at the Head Office of the Department, St. Clair Experiment Station. It contains standard works on General Agriculture, Horticulture, Botany, etc., and books and periodicals- dealing with Cacao, Sugar, Coconuts, Rubber, Cotton, Corn, Fruit, Tobacco, and other crops. BOARD OF ACxRICULTURE. President His Excellency the Governor. Vzce- President The Director of Agriculture. Hon. Sir Norman Lamont, Bt. „ Sir G. Townsend Fenwick, K.C.M.G. „ C. de Vekteuil. „ W. G. Kay, O.B.E. „ R. S. A. Warner, K.C. J. \V. Arbucklb. ,T. P. Bain. J. Black. A. B. Carr. Joseph d'Abadie. L. de Verteuil. \V. Greig. W. C. Jardinb. J. J. McLeod. C. S. Rogers. C. F. Todd. W. S. E. Barnardo. .J. J. Carlbe. Acting Assistant Director of Agriculture. Mycologist Entomologist F. W. Ukich, F.E.S., C.M.Z.S. Secretary Jos. E. Seheult. (F. Y>. Davies, Tobago. Agricultural Advisers « \C. M. Roach, San Fernando. (l. Mota, Rio Claro. Laboratory and Field Assistant W. Buthn. Standing Committees. I Advisory Committee. — This consists of all the members of the Board ; five as a Quorum. Finance Committee. — The Director of Agriculture, Hon. SirG. Townsend Fenwick, K.C.M.G., Hon. Carl de Verteuil, Messrs. Wm. Greig, J. J. McLeod and A. B. Carr. Cacao Committee. — The Director of Agriculture, Messrs. J. d'Abadie, Ludovic de Verteuil, J. P. Bain, A. B. Carr, W. C. .Jardine and W. S. E. Barnardo. Sugar Committee. — The Director of Agriculture, Hon. Sir Norman Lamont, Bt., Hon. Sir G. Townsend Fenwick, K.C.M.G., Hon. W. G. Kay, Messrs. C. Forbes Todd, J. Black, J. J. McLeod and J. W. Arbuckle. Rubber Committee. — The Director of Agriculture, Hon. Sir Norman Lamont, Bt., Hon. R. S. A. Warner, K.C, Messrs. C. S. Rogers and Wm. Greig. Government Farm Advisory Committee. — The Director of Agriculture Messrs. J. W. Arbuckle, J. J. McLeod, J. Black, C. Forbes Todd and Statistics Committee. — The Director of Agriculture, Hon. Sir Norman Lamont, Bt., Hon. Sir G. Townsend Fenwick, K.C.M.G., Messrs. W. C. Jardine, Wm. Greig, A. B. Carr. Agricultural Exhibition Committee. — The Director of Agriculture, Hon. Sir U. Townsend Fenwick, K.C.M.G., Hon. W. G. Kay, and Mr. Ludovic de Verteuil. Vl, Department of Agriculture. GOVERNMENT STUD ANIMALS. The following are the arrangements for November and December with regard to Stud animals of the Government Farms in Trinidad and Tobago. Stallions. Where standing for Service. ...Govt. Farm Trinidad ...Govt. Farm Name. Class. Fee. QuicKMATCH. Thorough -bred Nels WEEP... Thorough-bred Sii^ HoKRY...Tlior'gh-bred Hackney.. Govt. Farm RiLLiNGTON Spartan. .Cleveland Bay. .Govt. Farm Mahat ...Thorough-bred ■Jack Ml )iarch ...American Donkey President ... Do. do. Barbados Joe Tobago A.- TRINIDAD. ^^ ...Roxburgh, Donkeys. . . . Govt. Farm, Trinidad. . . ...Govt. Farm, Tobago... . . . Govt. Farm, Trinidad . . . Bulls. At Government Farms. TOBAGO $ 10.00 10.00 5.00 5.00 5.00 Oroom's Fee. 60c. 60c. 60c. 60c. 60c. 5.00 5.00 1.20 60c. 60c. 60c. Class. 2 Pure-bred Zebu 1 ,, Jersey 3 Half-bred Red Poll 1 Half-bred Holstein 1 Half-bred Shorthorn B.— At Place, Queen's Park Savannah Mucurapo Pasture St. Clair Exjat. Station St. Augustine Estate River Estate San Fernimdo Harmony Hall Estate Arin;a Tobago, Friendship Est. 1 Fee. « 1.20c. 2.40c. ] .'20c. l.'20c. 1.20c. PoBiiic Pastures Class. Pure-bred Zebu 1 Half-bred Guernsey OR Estates. Class. Fee. ..$1.00 1.00 1 Half-bred Holstein. 1 Half-bred Guernsey. 1 Half-bred Guernsey. 1 Half-bred Jersey. White Yorkshire, Berkshire ,„ Berkshire 1 Half-bred Shorthorn ; 1 Half-bred Shorthorn : 1 Half-bred Holstein. 2 Half-bred Holstein; 1 Half-bred Zebu ; 1 Pure-bred Holstein ; 1 Pure-bred Shorthorn. 1 Half-bred Jersey. 1 Half-bred Holstein. Pigs. At Government Farm, Trinidad. Poland China, Berkshire, Tamworth $1.00, and Attendant's Fee 25c. At Government Farm, Tobago. ...Fee 50c. At St. Clair Experiment Station. ... $1.00 and Attendant's Fee 25c. POULTRY. Government Farm, Trinidad. Eggs of Barred Plymouth Rocks, Rhode Island Reds, White Leghorns ... ... .. $1.00 per doz. Great Kind Pigeons ..; ... ... 40c. and 60c. per pair. Government Farm, Tobago. Eggs of Plymouth Rocks, Black Minorcas, Rhode Island Reds 48c. per doz. Al^o Cocks and Pullets of Plymouth Rocks and Rhode Island Rpids, 4 vu. Department of Agriculture. NURSERY STOCK. Cacao, Limes and any other plants required in large quantities for delivery for early planting in 1920 should be ordered now ; address letters to the Superintendent, St. Clair Experiment Station, or to the Officer in Charge Botanic Station, Tobago. Special quotations at St. Clan- for Cacao, Coffee and Limes grown from selected seeds are as follows : — Plants purchased in lots of 1 to 1,000 plants \ 3 cents per plant. I Delivered at Nurseries Plants purchased in lots of several thousands uncrated. 2^ cents per plant. •' Plants purchased in lots up to 100 at 4 cents \ delivered at Railway per plant. Station, Port - of- Plants purchased in lots up to 1,000 at Spain or Queen's $3.50 per 100. | Wharf, securely Plants purchased in lots of several thousands at 133.00 per 1,000. Tobago prices on application at the Botanic Station, Scarborough. Budded Avocados select varieties at 12 cents. Budded Oranges at 24 cents and Grafted Mangos at 24 cents should also be booked at once. Budded Cacao 12 cents each or in lots of over 100 at 8 cents. Limes from beds 1^ cents per plant for lots over 100. A select stock is also kept of other fruit, ornamental and flowering trees, palms, etc., a list of which can be obtained on application. Large orders must be booked six months previous to the date when the plants are required as large supplies are not kept on hand for casual demands. packed in open crates. Board of Agriculture. SPRAYING CACAO, &c. From September to November is the time for spraying cacao trees for the prevention of thrips and black I'ot ; and early in the dry season for the Algal disease, die back, and cacao beetles. The Board of Agriculture has on hand a supply of bluestone, which is sold to planters at 12 cents per pound, also nicotine sulphate the best insecticide for thrips, which is sold at 114.50 per gallon. Men will be provided to superintend any spraying work which estates maj' wish to have done. Spraying Machines can also be hired in Trinidad or Tobago. Friend Pump, with two leads of hose and rods complete, $1.00 per week. Barrel Pump with one lead of hose and rods, 50c. j)er week. Carriage to and fro extra. Further information in regard to cost of spraying, etc., and applica- tions for bluestone and nicotine sulphate should be made to The Secretary Board of Agriculture, Port-of-Spain. Vlll. PUBLICATIONS FOR SALE. The Bulletin issued quarterly, price sixpence per number or two sTiillings per annum post free in the Colony. To other subscribers postage extra. Vol. XVIII. 1919. Ft. i.— Wither Tip of Limes (Illustrated) ; Yam Experiments 1918-19 ; Cultivation of Cotton ; Nitrogen Content Cacao Soils ; Supposed Cure for Froghoppers ; Bedding Plants for Trinidad ; Fungous Diseases of Roses (Illustrated) ; Prize Competitions 1918-19. Vol. XVIII. Pt. 5.— Cane Farmers and Co-operation ; Boot Disease and Froghopper Blight ; Control of Cacao Thrips ; Rice Experiments, 1915-18 ; etc., etc. Vol. XVIII. Pt. 5.— The Avocado in Trinidad and Tobago (Illustrated); Sugar-Cane Experiments 1917-19 ; Yams 1918-19. Our Local Foods : Their Production and Use, by W. G. Freeman, and R. 0. Williams.— Price 3d. The Dasheen : Its Uses and Culture. — Illustrated. — Price 3d. The Avocado in Trinidad and Tobago. — Illustrated. — Price 3d. Insects Affecting Vegetables in Trinidad and Tobago, by F. W. Urich. Symptoms of pests. Treatment, Preparation of Insecticides, etc. — Illustrated. — Price 3d. Life History and Control of the Cacao Beetle, 3 coloured plates, by P. L. Guppy. — Price 6d. Insect Notes for 1910-11. Miscellaneous Notes on Cacao Pests, by F. W. Urich.— Price 3d. Notes on some Insects affecting the Coconut Palm, one coloured plate by F. W. Urich and P. L. Guppy. — Price 3d. The Cotton Staineu Bug (Illustrated), by P. L. Guppy and Thomas Thornton. — Price 3d. Rearing of the Vermilion Froghopper Egg Parasite, by F. W. Urich.— Price Id. The Sugar Cane Froghopper, six plates (3 coloured), by F. W. Urich. — Price 9d. The Surinam Witch-Broom Disease of Cacao, by J. B. Rorer. — Price 3d. The Froghopper Egg Parasite and its Colonization in Cane Fields, by F. W. Urich. — Price Id. The Mongoose in Trinidad and methods of destroying it, 2 plates, by F. W. Urich.— Price 3d. Control of Cacao Thrips. (Illustrated) by F. W. Urich. — Price 3d. Annual Reports, Department of Agriculture, 1916, 1917 & 1918.— Price Is. 9d. each. All publications can be obtained from the Head Office of the Dcpart- tncnt, St. Clair Experiment Station, post fi'ee within the Colonj'. The Bulletin is also on sale at Messrs. Muir, Marshall, and Davidson & Todd, Port-of-Spain. HULLETIN OF THE DEPAR,a^:MEisr'^r of aq-rioulttjiie Trinidad, and Tobag-o. Part 4.] 1919. [Vol. XVIII. i Stafi Changes. The Secretary of State for the Colonies has appointed Mr. W. G. Freeman Director of A.griculture, as from May 1, 1917 the date of retirement of Professor P. Carmody. Mr. Freeman has been acting as Director since February 1, 1917. Mr. .7. B. Rorer, the Mycologist of the Board of Agriculture who was granted one j'ear's leave from November ]918 to take up a temporary appointment with the Asociacion de Agricultores del Ecuador has resigned and is remaining in Ecuador. Mr. R. 0. ^Villiams, Curator of the Royal Botanic Gardens and St. Clair Experiment Station has been appointed Agricultural Superintendent of Grenada. Mr. L. H. Patterson who was appointed Clerk and Overseer at the Government Farm, Trinidad on July 1, 1919 retired from the Service owing to ill health on October 31, 1919. Mr. Francis Chookolingo has been promoted to the post of Clerk, Botanical Department as from February 1, 1919. Mr. Ali Hosein was confirmed in the post of 3rd Clerk at the Head Office on August 1, 1919. He has been acting since Tune 1916. Mr. Ashrafi' Hosein has been appointed Clerical Assistant to the Superintendent of Field Experiments as from November 1, 1919. Bntomolog-ical Conference. The Conference of the Entomologists of the Empire which had to be postponed from 1914 is to take place in June 1920 in London. Mr. F. W. Urich, Entomologist and Mr, C. B. Williams, Entomologist in charge of Froghopper Investigations, will attend as representatives of the Colony. Fi'Oghopper Investigations. Mr. W. Nowell, D.I.C., Mycologist on the Staff of the Imperial Depart- ment of Agriculture for the West Indies paid a second visit to Trinidad during October and November when he continued, in collaboration with Mr. C. B. Williams, M.A., the investigation of the part played by root disease in causing the condition generally known as blight. Mr. Nowell gave a short summary of the results obtained at the November meeting of the Board of Agriculture. A full report will be issued later in con- tinuation of the former one (Bulletin — Department of Agriculture Vol. XVII. 1919). Centenary of the Royal Botanic Gardens. The Botanic Gardens of Trinidad has completed a century of uninterrupted work and is thus one of the very few tropical gardens of L 176 TRINIDAD AND TOBAGO BULLETIN. [XVIII. 4. the Empire which has had a continuous existence of one hundred years. To mark the Centenary it was hoped to publish this year, as a number of the Bulletin, a historical sketch of the Gardens and a descriptive account of the principal economic and ornamental plants of the Colony and their uses, etc. Pressure of other work, and a reduced staff, has prevented this being done, but the work is so well advanced that it will probably be possible to issue it as No. 1 or 2 of the Bulletin for 1920. Appreciation of Cane Farmers' Competitions. In a recent number of the Louisiana Planter a summary is given of the Report on the Cane Farmers Prize Competition in Trinidad, of 1918, and the value of the method as a means of Agricultural Education pointed out. The suggestion is then made that similar competitions would serve a useful purpose in Louisiana. " It is a recognized fact that the hill lands of Louisiana and of Mississippi have made, and can again be made to produce, as high as 200 bushels of Indian corn per acre. As the common production is scarcely one-tenth of these prize figures we only cite them in order to show what can be done even under adverse conditions and the desirability of testing out these matters by prize competition and so we may all learn a lesson from our confreres in Trinidad and inaugurate prize competitions for sugar cane produced here in Louisiana." Sugar Research Association. "The West India Committee Circular of December 25, 1919, reports that at a Conference of Research Associations held during this month, Mr. A. J. Balfour, who presided, said, in his introductory address, that the industrial progress of mankind was going to be in the future more and more dependent upon the alliance of science and industry, and upon the co-operation of different branches of science with each other. It was only upon our increasing knowledge of the powers of nature that we could hope to improve the material lot of men. That knowledge could only be gained by the cultivation of pure science, of knowledge for its own sake, by contriving to educate men who, with no thought of self- advancement, were consumed by a curiosity to know, and, when, that stage had been passed, by learning how to apply the knowledge which they had disinterestedly acquired to the great purposes of industrial development. " One of the Research Associations represented at the Conference is styled the British Empire Sugar Research Association, which has been formed to establish an Empire Scheme for the scientific investigation of the problems arising in the sugar industry. Another aim is to encourage and improve the technical education of persons who are, or may be, engaged in the industry. The Association is working in co-operation with the Imperial Government Department of Scientific and Industrial Research. The scope of the work includes the improvement of the sugar-cane, the various methods of extracting sugar, of refining it, and the best methods for the use of sugar as a raw material. Another point is the discovery of the best uses of the after-products of bothfactorj' and refinery. Sugar planters should heartily support this Association, as all research work on sugar will directly benefit them. The registered offices are at Evelyn House, 62, Oxford Street, London, W." 1919.'\ 17V Trinidad Exhibit in Canada. At the request of Dr. Marin the Board of Agriculture agreed to present a collection of the economic products of the Colony to the Laval University, Quebec. This was done and a letter of thanks have since been received from the Rector of the University. The following note is taken from the Quebec Telegraph of December 5, 1919 : — " An exhibit that should be of deep interest to Canadians who have been following the much discussed matter of trade relations between €anada and the British West Indies has been given to Laval University of Quebec by the Trinidad Government, and has been brought to the University by Mr. R. G. Marin, M.B., a student of that Institution, and a native of Trinidad. "The exhibit consists of a unique display of the products of the island of Trinidad, which is situated in the extreme southern end of the West Indies archipelago, immediately off the northern coast of Venezuela, and one of the most precious of Britain's many small but important possessions. Mr. Marin has on display seven different grades of sugar obtained from Trinidad. There are also specimens of cane sugar, and bottles of white and coloured rum that are by-products of the sugar cane. The rum produced in Trinidad is of a delicious flavor, and possesses a 'kick' that is hardly to be equalled by many of the finest whiskies. " In the exhibit there are specimens of cocoa beans, both in the raw and the cooked state. The exhibitor has a number of coconuts, which are excellent food when eaten fresh, and from the shells of which are made many other products such as fibre ware. " Trinidad's position as a timber country is shown in the exhibit. Samples of various tropical woods are shown, such as different grades of mahogany, cypre and purple heart. The island is fast gaining reputation for furniture manufacturing. " In brief, the exhibit given the University by the Trinidad Govern- ment demonstrates better than anything could do, the benefits that would be derived by trading more extensively with this part of the world, which, being a portion of the British Empire, would serve to keep trade within the Empire as much as possible to the benefit of all concerned in the commercial relations." W. G. FREEMAN. 178 T BIN ID AD AND TOBAGO BULLETIN. \XVIIL 4, PLANT DISEASES AND PESTS. A ROOT DISEASE OF CACAO IN TRINIDAD. ROSELLINIA PEPO. By W. NowELL, D.I.C. with an introductory note by W. G. Freeman, B.Sc. The death of Cacao trees from "root disease" has been known in the Colony for a long time, but does not appear to have been specially investigated. The cause of death has often been assigned vaguely to "canker at the root." The root diseases of cacao and limes in some of the West Indian Islands have been the subject of research by Mr. W. Nowell, D.I.C, Mycologist on the Staff of the Imperial Department of Agriculture for the West Indies. His results are published in a paper " Rosellinia Root Diseases in the Lesser Antilles" V/est Indian Bulletin XVI. 1917 31-71 with twelve illustrations. During Mr. Nowell's visit in 1918 to investigate the Froghopper blight of Sugar cane, he expressed to me his belief that although Rosellinia had not been recorded as a cause of root disease of cacao etc., in Trinidad and Tobago, it would be found here, considering its wide distribution in the West Indies and tropical America. Root disease of cacao is not very common in the Colony, and as Mr. Nowell had very little time available he had few opportunities for searching for it. A few trees were examined but without definite result. During his second visit in 1919 Mr. Nowell and I visited an estate where trees in a particular area had died, special attention being directed to it by the hibiscus hedge dying out along the length of the same bed in which the deaths of cacao trees had occurred. 1919.] BOOT DISEASE OF CACAO IN TBINIDAD. 179 The section of the estate has recently been drained, and supplies planted to replace missing trees. The state of affairs found is represented in the foUomng diagram : — Hibiscus Hedge.— Dead. Q xxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxx xxxxxxxxxxxxxx s t. t T. t --t. D S. t t. t t. s t. D - T T. , T. T. Apparently healthy trees S. Sickly trees D. Dead trees — Missing tree t. Young supplies... 4 3 2 1 9 Total... ... 19 Mr. Nowell examined the trees etc., and diagnosed the cause of disease as Rosellinia Pepo which is described in detail later. The roots of the dead and dying hibiscus showed the smoky green mycelium of the fungus (Fig 4.) The roots of the recently killed cacao trees had the characteristic fans of white mycelium between the bark and the wood. (Fig. 3.) Fruiting stages were found on the cacao and also on the stump of an Immortel in the next bed which had also died. The following account of Eosellinia with special reference to its attacks on cacao, is taken from the paper by Mr. Nowell referred to above. The blocks of the illustrations have been kindly lent by Sir Francis Watts, K.C.M.G., D.Sc, etc., Imperial Commissioner of Agricul- ture in the West Indies. It should be noted that the disease is presumably not an introduced one. The fungus which causes it is native to tropical America and the West Indies, occurring in the forests, and is distributed by pieces of dead wood with the fungus on them being washed down to low lying areas on cacao estates. The disease can be got rid of by careful attention to the measures recommended by Mr. Nowell (p. 189). The position is therefore that planters have not a new disease to contend with, but now know the cause of a disease of old standing and know also how to eradicate it. The disease is however a serious one and neglected may lead to severe losses. W. G. F. 180 TBINIDAD AND TOBAGO BULLETIN. [XVIII 4. ROSELLINIA PEPO., Pat. This species was originally described by Fatouillard in 1908 from material on the bark of Hymenaea Courbaril collected by Duss in Guadeloupe. In the British Antilles the perithecia have been collected in Dominica, St. Lucia, and Grenada. From the published accounts of root diseases in Jamaica, Porto Rico and Martinique it seems probable that the species also occurs in those islands. Its most general importance is due to its attacks on cacao, but it is capable of producing destructive effects on any of the ordinary crop plants, herbaceous or woody, which are planted on land recently cleared from forest. Under such circumstances, limes in Dominica have suffered severely from this species, as well as from E. hunodea. Where cacao trees have been killed by the fungus and other plants have been put in for temporary fillers, I have seen dasheens, bananas, pigeon pea, cassava, and horse bean all attacked. Sugar cane has several times been seen to survive, but I cannot say that it is really immune. Barber includes it in his list of plants affected. Patouillard's description of the fungus is as follows (trans.) : — Perithecia scattered or in groups, situated on the crustaceous conidia-bearing subicle, globose, somewhat stalked, '2.5 to 3 millimetres in diameter, dark brown carbonaceous, furnished with a conical shiny black osteole, remaining closed, surrounded by a darker somewhat more flattened areole ; asci elongate, capitate at the apex, furnished with an ovoid pore, turning blue with iodine, much attenuated below, eight- spored, 10 to 12 microns in breadth ; paraphyses numerous linear ; spores brown, straight, fusiform, pointed at each end, measuring 62 to 67 by 8 to 9 microns, at first increased at each end by a glassy halo, later bare. There are present erect conidiophores (Graphium) 1 to 3 mm. in length, 30 to 60 microns broad composed of brown septate hyphae 4 to 6 microns thick, situated on the crustaceous subicle. Conidia not seen. The perithecia are borne, usually at the base of the stem, amongst and in succession to the conidial fructifications, on the somewhat carbonaceous layer which is formed on and in bark which has become thoroughly infested. The perithecia are formed much less freely than in the case of i?. bunocles, and in spite of long-continued search, material containing ripe asci has only once been obtained in the British islands : this was found by the writer on a dead lime tree in Dominica, in a situation with an annual rainfall of some 250 inches. Examination of this material at Kew enabled Miss E. M. Wakefield to identify the fungus as Patouillard's species. The perithecia are normally slightly verrucose (Fig. 1) but are sometimes found smooth. Apparently this is due to weathei'ing, though possibly (cp. B. hnnodes) there is some variation in the amount of roughness developed. Fig. 1. ROSELLINIA: PERITHECIA. x 3^. Fig. 2. ROSELLINIA: CONIDIAL FRUCTIFICATIONS, x U. \ 1919. \ ROOT DISEASE OF CACAO IN TRINIDAD. 181 The conidial fructifications are of the Graphium type figured by various authors in connection with Rosellinia necatrix and other described species. They occur previous to the development of perithecia and are borne on the black surface mycelium which develops wherever the fungus reaches the open under damp conditions. Each has the form of a black bristle-like stalk 2 to 3 mm. long, built up of perpen- dicular hyphae which branch out freely at the top into a tuft, which is white or whitish to the naked eye from the conidia which cover it. The conidia are borne laterally towards the terminations of these branches ; the cells which bear them have a somewhat zig-zag or corkscrew appearance from their tendency to bend away from the point of attach- ment of a conidium. The conidia are rounded or oval, one-celled, about 5 microns in length. The conidial fructifications are developed in very great abundance (Fig. 2) and have been seen on dead leaves, twigs, and old lime skins lying under close shelter beneath infested trees. The most striking characteristic of this species is the production of fans or stars of white mycelium in the region of the cambium (between bark and wood) of the roots (Fig. 3). The presence of these distinguishes it at once from B. hunodes. A somewhat similar appearance may be produced by the unidentified species (C), but in the examples of the latter fungus seen, the growth has been very much less vigorous, On the roots the mycelium forms an irregular coating over the surface. In its early stages it is smoky grey in colour, but soon becomes black. It is gathered at first into rather loose branching strands with spreading hyphae between them. Later the whole is combined into a layer which is more or less woolly on the surface, and tending to be carbonaceous below. It forms dense layers and pockets in the outer bark, and from these whitish strands more or less vertical to the surface everywhere penetrate the cortex. On reaching the surface of the wood these repeatedly branch and spread in all directions over it, so that when ' bark ' and wood are separated, a conspicuous white pattern of branching lines, stars and fans is seen on the surface of the wood and repeated on the inner surface of the ' bark.' From this layer strands penetrate the wood in radial lines along the medullary rays, and send out hyphae which invade and fill the large vascular elements. In this species the mycelium in the wood, owing to its lack of colour, is not apparent to the naked eye unless a cut surface is exposed for a day or two, when the hyphae grow out and turn black. In long-infested wood, thin plates, seen as black lines in a section, mark off certain areas, anrl are believed to belong to this fungus. Such plates, however, are very common in dead wood, and so have little diagnostic value. The external mycelium is most fully developed and conspicuous when the fungus reaches the base of the stem and appears above the surface of the soil. It is then seen in broad spreading fans or an advancing sheet, which from the beginning or at an early stage encirclfS the stem (Fig. 4). The margin while actively advancing is light grey in colour for a width of about half an inch, behind which the colour shades off to brown or black with a greenish tint. On lime bark the sheet is smooth and glossy rather like wet fur. 182 TRINIDAD AND TOBAGO BULLETIN. { XVIII 4. The height to which the fungus reaches is determined by the moisture conditions. When the stem is well exposed it reaches no further than the few inches for which the moisture of the soil can affect it ; if the stem is enclosed by weeds, or low branches, or sheltered by a log, it commonly goes up for a foot or more. In a case seen of a bread- fruit tree growing against a bank 4 feet high, it extended upwards for that distance. The limit of the external mycelium is also the limit of the ultimate infestation of bark and wood. If a diseased tree is up-rooted, or is cut below the limit of infestation, and thrown aside where weeds grow up and shelter it, the fungus extends to tlie whole of the stem and branches thu3 kept moist. In the rootstocks of herbaoeou.i plant <, as in tliick soft bark the firm round strands of mycelium, buff-fulouied without, white within, penetrate the parenchyma in all directions. MODE OF CONCURRENCE OF ROSELLINIA. DISEASES. As seen in the West Indies, the diseases due to Rosellinia, with the exception of that on arrowroot, occur ; (a) on land recently cleared from forest, still containing the dead and dying stumps of the forest trees and retaining a considerable amount of the forest humus ; (b) in cacao cultivations the conditions in which, especially where shade trees are abundant, appro9ch more or less closely to those of forest in respect of shade and humidity ; and (c) in wind-breaks and hedges of certain susceptible trees in wet districts. The prevalence of the diseases is very distinctly governed by humidity. The types due to Rosellinia Pepo and Rosellinia hunodes, which alone have any consider- able economic importance, are most virulent in the wet uplands of Dominica, St. Lucia and Grenada; the former follows the cacoa cultivations down the more sheltered valleys to the coastal districts ; the latter has not been met with away from the hills. The Centres of the Disease. a. IN NEW CLEARINGS. The fungi concex-ned have not been found in a purely natural habitat, -i.e., in undisturbed forest, although sought for to some extent. From the mode of their appearance in recent clearings there can however be little doubt of their existence there as a part of the natural flora. It is the usual custom in these islands, when clearings are made, to burn as much as possible of the smaller material, but to leave the logs on the ground to rot, and to make no attempt to remove the stumps, Many of the latter send up suckers which have to be cut away from time to time. Under these circumstances it takes very many years before the logs and stumps finally disap[)ear, and during the course of their decay the3' malie the soil around them dangerously rich in crumbling woody matter and humus. On land so prepared as soon as the felling and bunring are finished, nursery plan'^s are set out in tiie spaces between the stumps and logs. To get anything like legularity of stand many have ix> be [ila-jed close up to these obstacles. ■M mWlTTy*., - 1 ^-x-^^MMT-^-i^jflJ^ Fig. 3. EOSELLINIA: WHITE MYCELIUM UNDEFl BARK. Nat. size. ^'■- r^rw Pig. 4. EOSELLINIA: SMOKY MYCELIUM ON SUEEACE OF BAEK. x U. 1919.\ ROOT DISEASE OF CACAO IN TRINIDAD. 183 Fungi are of course very abundant on the decaying material, but the Rosellinias are far from being conspicuous among them. I have once found in Dominica a large decayed log infested with the mycelium of Rosellinia bunodes, as shown by the infection at the point of contact of lime branches touching it, and infection of a shrub growing upon it, and have found three other species on Erythrina logs in a St. Lucia cacao cultivation. Nor have the Rosellinias been found so often as might have been expected on forest stumps. In a fruiting condition they are in fact rare in this situation. The most notable case T have seen was that of a chataignier stump {Sloaiiea sp.) covered with perithecial and conidial fructifications of R. Pepo, which from its position appeared to be the centre of infection of a large group of diseased limes. The presence of the mycelium on the buried roots of forest stumps is more frequently observed. Every infested clearing shows examples of the association of diseased trees with stumps, and sometimes these are very striking, as when a group of five or six dead and dying trees is seen around a large chataignier. The actual nature of the connexion is usually difl&cult to demonstrate ; as a rule the cases when seen are too far advanced for sure conclusions, and often they have to be passed over for want of time or means for the uncovering of the roots. But from first to last a good many cases have been investigated in which the roots of diseased trees have been found in contact with roots of forest stumps bearing the fungus. In some of tliese the evidence that the fungus passed from the stump to the lime tree is quite definite. Two examples in which the evidence includes the identity of the forest tree may be cited. South (1913) reports having followed up the fungus from dead mahoe cochon (Sterculia caribaea) to the roots of a living lime tree; the writer examined a large stump, still bearing a few living suckers, of chataignier grand-feuille {Sloanea Massoni) the roots of which were badly infested and had recently communicated the fungus to the roots of a lime tree in contact with them. In other cases a single root coming from the direction of a stump has been found to be infested when all others were sound. From the nature of the case, examples in an early stage are only found by accident or a lucky shot, so that one is justified in assuming that a fair proportion at least of infections near stumps take place in this way. The fact remains that considering the area of the clearings, the number of infested stumps does not appe ir to be large. Relatively few trees are lost in the first three or four years after planting. This is in part due to the time taken (a) by the fungus to develop on and about the stumps, (b) by the roots of the planted trees to grow out into the infested area, and (c) by the fungus to kill a tree after infection. But observation shows that when the period of heavy losses ensues, most of the trees are infected from one another, so that the characteristic distribution of the disease is in scattered patches whose number is very small compared with that of the stumps and logs in the clearing. There is strong reason to believe, and the idea is supported by experience in other countries, that the number of forest trees whose stumps readily serve as centres of distribution for the fungus is quite 184 TEINIDAD AND TOBAGO BULLETIN. [XVIIL 4. limited, and that the presence of the stumps of these especially suscep- tible trees in dealings h is 'i good deal to do with the appearance of the disease. It is a well-known fact, already referred to above, that there _ is such a special susceptibility in the case of certain cultivated and semi- cultivated trees. Accurate information as to the identity of the forest trees most concerned is difficult to obtain. By no means all the forest trees have been identified, and to such as have, the patois names which form the connecting link with local knowledge are often loosely appUed. In Dominica a large number of cases certainly occur in connection with deeply buttressed stumps com- monly referred to chataignier, a name usually identified with two or three species of Sloanea. One planter has suggested that the closely similar stumps of bois cote are in his district more com- monly the source of the trouble. Infection from the roots of mahoe cochon {Sterculia caribaea) and chataignier graud-feuille {Sloanea Massoni) in Dominica has been already mentioned. South and Brooks give mahoe piment {Daphnopsis tinifolia) and bois cabrit or goatwood [Algiphila martinicensis) as susceptible trees in St. Lucia. The perithecia of 'B. Pepo were described by Patouillard from locust {Hyjnenaea Courbaril) in Guadeloupe. The disease is unknown in the older lime estates, which have no recent clearings. This cannot be regarded as wholly due to the much lower rainfall which most of them receive, since even near the coast lime trees contract the disease when planted as substitutes for diseased cacao. There is moreover at least one forest estate in the same district as some which are badly affected, where the clearings are old enough for the stumps to have disappeared, and where, in the limes which have replaced the crops first planted, root disease has given no trouble. In comparing this position with that of cacao cultivations, in which the disease due to B. Pepo is very liable to appear after they have been long established, it has to be remembered that the canopy is not so dense in a lime field, and that shade trees are not grown. b. IN CACAO CULTIVATIONS. In the great majority of cases the disease occurring in cacao has its origin in the trees grown for shade. When these are cut out, aa often becomes necessary as they get too large, the stumps are left to rot and a condition is produced comparable in essentials with that in the clear- ings just discussed. The danger is well known to planters, especially with regard to breadfruit and avocado pear trees. A Grenada planter of long experience claimed th it on several occasions whea root disease had appeared in his cacao he had been able to trace it to the decay of breadfruit roots cut through in digging drains. I have seen the fungus on stumps of cacao trees which were healthy when cut down in thinning operations. Apart from this, trees ot the kinds named are rather liable to die of .their own accord. How often this is due to their contracting Rosellinia disease, and how often they become infested with that fungus only after the death of some or all the roots from other causes, I can form no opinion. When, as often happens, the stumps are those of healthy trees, cut down for other reasons, obviously the latter is the Fig. 5. ROSELLINIA: EARLY STAGE OF INFECTION ON CACAO ROOT. Nat. size. 1919.\ BOOT DISEASE OF CACAO IN TRINIDAD. 185 case. The observed facts as they regularly present themselves are these : that one or more of the cacao trees immediately adjacent to a sickly or a dead shade tree, or shade tree stump, begui to show symptoms of root disease, and removal of the soil reveals the fungus advancing along one or more of the cacao roots from the neighbourhood of roots of the shade tree, which are found to be infested, and usually in an advanced stage of infestation. Sometimes actual contact has been proved, sometimes not. In view of the difficulties of digging among roots the negative evidence has not much weight. The trees most often concerned in connexion with the the disease on cacao are avocado, breadfruit, and pois doux {Inga spp.). Immortel {Erythrina sp.) and mango are sometimes but not often involved. The fact should be mentioned here, though its discussion belongs rather to the next section, that the disease can occur on cacao trees in the absence of stumps or any obvious dead wood. Cases of this nature are as a rule uncommon, but in only one badly infested area examined a fair number were seen. Methods of Infection. Several of the authors cited in the first part of this paper refer to the spread of the fungus through the upper layers of the soil and in accumulations of decaying vegetable matter on its surface, resulting in the infection of trees at those levels. The usual mode of occurrence of the disease in the West Indian cacao plantations does not bring out this feature at all clearly. With the exceptions alluded to above, the disease is generally clearly traceable to dead roots, which are often deep underground, and its course is along one or more of the cacao roots in the direction of the stem. All stages of the process have been seen, and quite commonly in the less advanced cases the crown is found still unattacked. The cases sometimes met with of cacao trees becoming diseased in the absence of stumps can be accounted for by infection of the surface type. A livmg root was found which had been injured where it came to the surface, and from two points on the margin of the injuries white fans recognizable as the myceUum of B. Pepo were found radiating under the bark. This example is illustrated in Fig. 5. The cases noted have been in the wettest districts, where production of organic matter is at a maximum, and where cloudy days, the depth of shade produced by luxuriant growth, and the saturation of the soil with water, all reduce the rate of its destruction. Where rainfall and shade are not excessive, the addition of organic matter to the soil does not keep pace with its decay, and the general run of soil on the ordinary cacao estate is not particularly rich in humus, nor is there much, if anything, in the way of leaf mould on its surface. The spread of the disease along closely planted hedges and wind- breaks, of which some striking instances have occurred in St. Lucia, is characterized and probably mainly effected by infestation of the surface soil. The leaves and twigs which accumulate along the base of the wind- break, and decaying, enrich the soil with humus, and the shelter afforded by the trees and by the vegetation which grows up under their 186 TBINIDAD AND TOBAGO BULLETIN. \XVIIL 4. protection provide conditions especially suitable for the fungus. It creeps along the line like a smouldering fire, killing oil the trees and their seedlings, and most of the shrubby and herbaceous vegetation, as it comes to them. In a gap so produced, from which the stumps had been removed, a line of living fence posts subsequently put in consist- ing mostly of white cedar [Tecoma leiicoxijlon) were three months later infested to soil level. Wind-breaks of pois doux and galba {Galoj]hyllum Calaba) are very susceptible to the disease. - The evidence thus shows clearly that the spread of the fungus may take place in two ways : (a) underground along the roots of diseased trees or infested stumps, in which case one or more outlying roots of the new contacts are usually first infected and the fungus travels along them to the collar, infecting other roots as it crosses them; (b) by the growth of the fungus through rich and damp (which usually means shaded) surface mould and vegetable debris, in which case the fungus first attacks surface roots or directly infects the collar. How the infection originates is not known. Tradition, the whole course of planting experience, and many definite observations by agricultural ofl&cers, combine in associating the first outbreaks which occur with the presence of stumps in new clearings, and of dead or sickly shade trees in older plantations. The theory as to the general course of infection which seems to the writer to best fit the facts at present known is this : (1) that the fungus is able, by means of its spores (of which the conidia are by far the more abundant and the more likely to be distributed by the wmd) to infect any accumulation of decaying vegetable matter in damp soil ; (2) that the required conditions are most often presented in the immediate neighbourhood of mouldering logs and stumps ; (3) that a surface infestation thus begun may or may not com- municate the disease directly to the cultivated trees : in the earlier stages of a plantation the chances are considerable that it will not, owing to (a) disturbance of the humus-bearing surface soil in planting the trees, and (6) the lack of shade conducing to rapivl destruction of organic matter in the soil around ; (4) that infestations round about the stumps of certain trees, on the other hand, are communicated to the roots at and about soil level, the fungus finding in the buried roots a food supply situated in permanently congenial conditions, so that it is able to follow them out to their extremities however far and deeply they may run, thus establishing a long-enduring and wide-spreading source of infection for the roots of cultivated trees which extend into contact with them. As the trees grow large and produce a deeper shade, so protecting and keeping moist the organic matter which accumulates beneath them, the conditions for surface infection are greatly improved, and by this time, owing to the production of spores on the remains of the trees previously killed, the chances of any suitable patch of soil becoming infected are much greater. At this stage, therefore, the proportion of cases originating by direct infection from the soil will have risen, and such cases may in time far outnumber those associated with stumps. 1919.] BOOT DISEASE OF CACAO IN TBINIDAD. 187 Another type of situation continuously capable for a long number of years of becoming infested is presented by the soil on the shaded under- side of logs, the disintegration of which, especially that due to the tunnellings of insects, maintains a plentiful supplj' of organic matter. Once the disease has got a footing however, the greatest amount of loss is caused by the spread of the fungus along the roots (as it com- monly appears) or over the surface (where conditions of shade permit) from one cultivated tree to others about it in an ever widening circle. In one case the loss of about 150 trees appeared to be clearly traceable to two original centres of infection. Wherever a tree has died, unless strict measures have been taken to control the fungus, the adjacent trees almost inevitably contract the disease sooner or later. Such cases may arise years after the original tree has been removed and the cause of its death forgotten, so that they have the appearance of being sporadic. Examination of the position and age of supplies, and the keeping of records of surveyed areas enable them to be linked up with considerable certainty to previous losses. How far such belated cases are evidence of the slow progress of the fungus along the roots, or how far they are due to delayed infection has not been ascertained, but the general evidence points to the conclu- sion that the process of investment of mature trees is a distinctly slow one. In a case definitely recorded, a full}' infested dead lime tree was removed in October 1914, and the fungus {R. bunodes) was just coming up round the collar of the next tree in the row, a very large and vigoi'ous specimen, in August 1916. The variety of circumstances must produce wide differences, but I should judge that the two years taken in this case is not an unusual period, and is in some cases considerably exceeded. Typically an infested clearing in which the disease is of several years' standing shows a few large open patches, each representing perhaps a score of trees, with usually two or three around its margin dead or dying, and several more on which the fungus may be found. Sometimes two or three such patches have coalesced. Scattered about are fresh centres in various stages : a single tree, a gap of two or three trees in a row, with another going, or a group of two or three in diflferent stages about a large stump. Of the supplies put in, some are several years old and still thriving, others are dead within a few months of being planted. Appearance of Diseased Trees. As the disease is seen on lime and cacao trees there are two types of failure of the top. In the one, where the roots become more or less generally infested before the fungus gets fully hold of the collar, as commonly happens where its approach along the roots is checked by drier conditions around the crown, defoliation is gradual and is preceded by yellowing of the leaves and a general sickly appearance of the tree. lu cacao especially, this is the common form of failure and resembles a severe type of die-back, such as is brought about by poverty of soil or exposure. The development of vigorous suckers excludes R. Pepo as the cause of such a condition but their non-development on failing trees does not necessarily indicate its presence. 188 TBINIDAD AND TOBAGO BULLETIN. [XVIII. 4. The 'second type of failure common on lime trees in the districts indicated, and occurring sometimes on cacao, is produced when the stem is girdled by the fungus while most of the root sj'stem remains yet uninfected. In lime trees the earliest outward sign of the disease in such cases, so far as I have seen, is the production of an abnormally large crop of fruit. Presumably the production of flowers would be equally striking, but this I cannot say from observation. Before this crop of fruit has had time to ripen the foliage drops, often with such suddenness that the ground is carpeted with leaves still green. The appearance which the tree then presents is a familiar one in the affected districts : its branches nearly bare of leaves and hung with shrivelling and prematurely yellow limes. In an observed instance a tree of perfectly healthy appearance, with abundant dark foliage, was found on October 20 to have its bark all round and for some distance up the stem infected through and through with Eosellinia ; it remained green until November 17, and then the change from healthy foliage to naked twigs was completed in fi-om twenty-four to thirty-six hours. When relieved from less of water by the fall of the leaves a tree may put out a few small shoots and linger for some time before it completely dies. It often happens that as the bark near the soil level is killed, tufts of adventitious roots are pushed out from a callus formed at the edge of the sound bark above. Quite a dense mat of small roots is formed, some of which may get a good hold of the soil and thicken up. This sometimes enables the tree to struggle on a little longer, and even raises hopes of its recovery. Such an event is very improbable, as the new roots soon become infected after they reach damp soil. Incidence of the Disease. The disease as seen on the Dominica lime estates is by no means regular in its incidence. It is a matter of general and rueful experience that it develops its attacks most widely in the best clearings, and that the finest trees, which is to say those growing in the deepest and richest soil, are the most liable to be infected. In clearings on thin soil and on the considerable area of upland flats where the soil is underlain by a stony ' pan ' which prevents anything like adequate drainage, diseased trees are rare, and do not as a rule lead to further extensions unless they happen to be situated in a deeper pocket in the one case, or on a drier slope in the other. These experiences are exactly paralleled in Porto Rico, where 'the disease often does most harm amongst the best trees, the sun-exposed slopes of poor coffee plantations remaining quite free from trouble.' ' The only things which retard or stop its progress seem to be excessively dry or excessively wet soils, natural barriers, such as brooks, and the scarcity of food material (decaying vegetation) in the soil.' (Fawcett 1915.) This is not to say that slow-growing stunted trees are at all resistant to the fungus. Where the roots of such trees happen to come in contact with infected material they are killed as readily as any others. The explanation of this feature of the disease is to be found in the favourable conditions of shade, moisture, and abundance of organic matter, produced by the heavy canopy of well-grown trees. It is in such situations that soil infections, without the intervention of stumps, b 1919.] BOOT DISEASE OF CACAO IN TRINIDAD. 189 are very liable to occur. The comparative rarity of cases in the clearings on thin soils is in keeping with the theory put forward that the original sources of infection in any clearing are few in number. In poor clearings the cases mostly remain restricted to these. Something may be due however to the difference in the constitution of the original forest. In cacao plantations the conditions are usually more uniform, and differences in the distribution of the disease are not well marked. There is however a noticeable tendency for outbreaks to occur along the course of ravines and on small enclosed alluvial flats. Among cacao, in the situations so far studied, infection apart, from contact with stumps or diseased trees, seems, as already remarked, to be relatively rare. COUNTER MEASURES. Prevention. In new lime clearings. It would be a counsel of perfection to recommend the removal of stumps or even of logs from new clearings in their earliest stages. In West Indian plantations such a policy is not economically possible. But in arranging and planting new clear- ing for orchard crops, the probability that root disease will occur should be kept in mind, and certain precautions can be taken which will con- siderably reduce the trouble to be faced when disease appears. First among these is provision for the construction, immediate or when occasion and funds permit, of a complete and close system of trench drains. To this end the arrangement of the trees should be planned so that each block shall be isolated from the rest by main drains and, where possible, each row separated from the next by a trench. There will be many patches encumbered with logs and stumps over which for some years the system will extend only in the plan, but it is necessary to take long views, and too many cases have been seen where, when the need for a trench has urgently arisen, the line has been brought up against trees irregularly planted and now too valuable to be destroyed. Drains ai'e being considered here, of course, not in view of their primary function of removing water, but as isolation trenches preventing the spread of root disease from tree to tree. At the same time thorough drainage may be considered to have direct value from the point of view of Rosellinia disease, for although, as has been pointed out, the fungus does not thrive in water-logged soil, neither do the trees and when that condition has been passed, the drier the soil can become the quicker is the decay of organic matter and the less favourable the conditions afforded to the fungus. It has been not uncommon in both lime and cacao fields when a large stump has appeared to be a centre of disease, for a trench to be dug around it cutting off the widely extending roots. When the fungus has already got into the root system this measure usually comes too late, but if it is applied to large stumps at the outset, especially to those of susceptible species, it may be expected to have some success. Possibly a variation recently suggested by A. Sharpies (1915), namely the following out of each main root separately and removal of a section where it gets down to about 2 feet from the surface, may have the advantage over a trench that the cut ends are not left open to infection. 190 TEINIDAD AND TOBAGO BULLETIN. [XVIII. 4. On the other hand, without trenching all round it cannot be assured that all the roots are cut, and the smallest is capable of conducting the fungus outward or inward, as the case may be. The best plan would probably be to dig a trench some 2 feet wide well away from the stump, remove all sections of roots, and fill it in again. In planting the trees, positions in close proximity to stumps should as far as possible be avoided, and a good deal may be done in the way of re-arranging the smaller logs so that they do not form too close a shelter about the stem of the prospective tree. Beyond these measures little, for the time being, can be done. If the theory that the sour orange stock is more resistant than the lime is shown by the experi- ments now in progress to be well founded, then it will be advisable to plant such situations as experience has shown to favour particularly root disease with limes budded on that stock. When the first few years have passed and the logs are more or less rotted, it has been shown to be quite feasible to hasten very materially the time of their disappearance by cutting or breaking them up so that the^' can be easily handled. Merely to dispose of them better by dragging them away from the stems of the trees is a considerable gain, and in some cases it has been found possible to stack much of the material, and even to make good use of it for fuel. The great con- venience, quite apart from root disease, of having the ground clear, should be an additional inducement to the planter to make every possible effort to this end. A point to be always kept in mind is that wood which can dry out from time to time, e.g. logs, stumps, or parts of them which are raised above the soil and not shut in by weeds or overhanging branches, is in little danger of harbouring the fungus. The same consideration applies to the soil. In damp and sheltered clearings such as are favoured by the fungus, all that is possible should be done to encourage the free circulation of air beneath the trees. Low hanging branches which maintain a closely sheltered circle around the base of the tree induce conditions which invite surface infection, and should most certainly be cut away. Grass and weeds should be kept short all the time, not merely in the crop season. It is highly desirable in infested clearings and especially in the neighbourhood of infected spots, to go further and clear away the soil ^and weeds about the base of the stems, completely baring the collars, and liberally exposing the main roots so far as this may be done without forming a saucer in which water will stand. The treatment of the collar and the recesses between the roots with lime-sulphur solution to keep the bark free from moss gives an added protection of consider- able value. All these measures are summarized in the word ventilation, and cannot be too strongly emphasized. The fungus cannot tolerate dry conditions and it is for the planter to take every advontage he can of this weakness. 1919.] BOOT DISEASE OF CACAO IN TBINIDAD. 191 IN CACAO PLANTATIONS. There are probably few managers of cacao plantations who would nowadays plant breadfruit or avocado trees through their fields. The idea of the more economically minded of the old planters seems to have been that since shade trees were to be grown, they might as well be such as would give something in the way of food in return for the room they occupied. The modern idea of the uaauurial function of shade trees leads to a preference for leguminous trees, and justifies the more orthodox tradition which led to the planting of immor- telles. Where avocado and breadfruit trees are already established, the planter who has learnt respect for the root disease has two courses open to him. The one is to take the utmost care of such trees, to prune out dead branches, to avoid injuries to thu roots and generally to try to preserve them in health as long as possible ; the other is to take them out as occasion offers, removing the stumps, and following out and removing every root that can be got at. This is usually difficult because of the adjoining cacao trees ; where the trees to be dealt with are large, it becomes formidable. The easy course is to cut down or ring the the trees, and leave the roots to rot, but that way trouble lies. It does not always happen, but striking, one might say startling, cases have been seen where the cutting down of an avocado or breadfruio in the cacao, or a pois-doux by the roadside has led to the appearance of the disease in places from which it has thought to be far removed. These three trees are the chief victims, but there is none that can be considered to be really safe. It should be the settled policy of cacao planters in wet districts to leave no woody material to rot in the soil if it c