A FORTNIGHTLY REVIEW 



OF THE ' 



IMPERIAL DEPARTMENT OF AGRICULTURE FOR THE WEST INDIES. 





Vi XIV. No. 339. 



BARBADOS, APEIL 24, 1915. 



Price Id. 



CONTENTS. 



Page. 



Page. 



4gi n-iili lira] < Ynlit hi llic 



Port uguest I '" ! es . . 131 



Antigua, Ground Waters of 143 

 Britisli Press and West 

 Indian Agriculture ... 137 

 frees, Individuality 



in .'. 129 



Cassava. Varieties of ... L35 

 Cattle Testing for the 



Tropics 137 



I ii urn and Palm Kernel 



' akes 133 



Coffee, Cultivation of ... 132 

 Cotton Notes: — 



British Cotton Growing 



Association 134 



ton Experiments in 



Si Croix 134 



Exports of Sea Island 



Cotton 135 



\\ es' Indian Cotton ... 134 



Cow peas, < lolour of 133 



Culm. Land Development in 135 



I >. pail uient News 130 



' N i 



A Bacterial Disease of 



Lachnosterna Grubs... 14- 

 A Successful Introduc- 

 tion of Resistanl Varie- 

 ties of Ground Nut... 14:.' 



Gleanings 140 



Indig Fermentation of 137 



[nsecl Notes 

 The Sweet Potato Weevil 138 



Items of Local Interest ... 139 



I leguminous Crops ;i> Stock 

 F I 13G 



Market Reports 14! 



Nature Study in the Ele- 

 mentary Schools, Trini- 

 dad ' 137 



Notes and Comments ... 136 



I 'apaw, Fruiting Capacil \ 

 of :.. .. ... 133 



Publications of the Im- 

 perial Department of 

 Agriculture 136 



Rice S iils, Sn amp, i rases 

 of 141 



Students' Corner 141 



Sugai fndustrv:- 

 Tli, History of Sugar... 131 

 'I'll, Norit Process of 

 Manufacturing White 



Sugar ... 131 



Tin Planting of Canes in 



Demerara 131 



Tea, Manuring 139 



\\ esl Indian Products ... 14:! 



Individuality in Cacao Trees. 



■HK Trinidad observations' 1 concerning the 



natural yield of cacao plots open up a 



^subjecl which seems deserving of special 



consideration. The study of the natural yields of 



ii plots in that island has now been carried on 



for two years, and the objecl in view is to arrive al 



some definite idea of the extenl to which individual 



*BuVelin if the Departn > • anil 



Vol. XIV, Part I. 



groups of trees vary naturally asregards productiveness 

 under similar conditions of environment. It is 

 maintained that without such knowledge, the results 

 of tnanurial experiments are often misleading and the 

 conclusions unreliable. The figures published by t he 

 Trinidad Department of Agriculture already show that 

 the variation between the different plots on each i 

 ina\ be considerable. For instance, on a plot on one 

 estate, in 1912-13, the averag number of pods 

 picked per tree was 3121, whilst in another plot 

 nearby, the number was only 8 - 52. In 1913-14, the 

 first plot yielded 42-20, and the second, 17%38. It will 

 be observed that there was a general increase (due to 

 reason), but the relative productiveness in this case was 

 maintained. It is clear that if the hioh yielding plot Ul . |v 

 manured and the low yielding used as a control without 

 knowled >f the natural yields, most erroneous conclu- 

 sions as to the effect of manures might result. So far 

 as is shown by the limited figures available, the ratio 

 between the productiveness of any two groups of trees is 

 not altogether constant. In fact the higher yielding plol 

 in one year ma\ lie the lower yielding the next. This, 

 however, is more or less exceptional, and as ,■, general 

 rule it may be staled that with trees of the sarru ag< 

 and condition the tendency for a group of trees to 

 produce a certain yield is constant, though several 

 years' trials are required before the average yield can 

 be determined. 



The principle underlying natural yields m relation 

 to manurial experiments is that plots should bo tested 

 before they are manured. This moans the study of the 

 trees individually, and as a consequence a doubling ol 

 tin- time required before perfectly reliable manurial 

 results can be forthcoming. There is one feature of 

 manurial experiments ivith untested trees however, 

 that to some ex ten 1 constitutes a safe-guard, and that 



