130 



THE AGRK QLTUEAL NEWS. 



Aii.ii. 24, 1915. 



is the continuation oi ■ rimentsover a numbi 



irs. [f, as in the Dominica experiments a gradual 

 takes place in the treated plots of mature tri 

 irK concluded I hal this increase is the res 

 lie manurial ti 

 stanl factor and would nol sho\< it-- effecl in thi 



stead) rise, [n manurial experiments when an 

 increase is shown in th ir and continues to 



remain at the same level, it is more likel) to be 



i of individuality than in the former case. An 

 approximate idea of the value of manurial treatnv 

 can frequently b i in spite of a verj consider- 



able difference in individuality through its i :treme 

 i The effect, for instance, of mulching upon 

 cacao is sufficienl ly ua itself shown in sp 



my individual variation amongst the trees of 

 various plots. 



Possibly more instructive numerical results w< 

 be obtained from untested manurial plots by tal 

 the yields of individual trees, plotting a frequency 

 curve for each plot, and taking the mode rather than 



mean as representing the yield. It would seem 

 bat this method of treating the Trinidad fig 

 would be better than the presenl one ol just striking 

 a common average. It would show the extent of 

 i at ion : a wkle, Hat curve demonstrating a general 

 but small variation in almost ever) tree;.-, steep curve 

 indicating the presence of merely a few extreme types. 



The whole subject of undividuality has many 

 philosophical aspects of much interest, and t lay apply 

 to other crops as well as cacao. In orchard cultivation 

 the inattet is obviously of greater importance than in 

 arable Held work, because one has to deal in orchard 

 experiments with a much fewer number of plants, and 

 these are relatively permanent. Coco-nuts constitute 

 a crop in which considerable individuality has been 

 found to exist. A case has been observed by the 

 waiter in Barbados where a number of these trees 

 growing apparently under exactl) similar soil and 

 climatic iditions show remarkable variation as 



fards productiveness. It is worth remembering that 

 such observations are useful in 'the matter of seed -.elec- 

 tion. Statistical observations in connexion with thi 

 natural yield of coco Duts are being carried on in Trini- 

 dad on similar lines to those on cacao. Ii has been 

 Ion i id tor instance that fourteefl. plots containing trees of 

 presumably the -aim age show a variation of as much 



IT o to -J7.1 nuts per tree or a difference of 750 nuts 

 per acre. 



Wui Indian Bulletin, Vol. XI V, No. 2. 



Heretic question ma\ be fairly put forward as 

 to whether in the Trinidad experiment-- with cacao 

 and coco-nuts, the trees are planted at the same 

 distance apart. It is true that this question : 

 nothing to do with variation in the yield ol self, 



it doe- i see I quest ion as to whether 



ural yield of i a direct i isun of the 



yield pei a re. And in spite of the fact that in 



Trinidad the yield per L.000 trees is the conn t 



standard, th r basis, and the one which we 



are bound n to sooner or later is the 



natural yield pet acari I would be interesting 

 learn the result of expressing the Trinidad average 

 yields of pods per tree in terms ol Ids 



icre. 



A further consideration which must, not be oa 

 ked in thes< experiments is the existence of a peri 



Of maximum yield. The \'i< Id of a cacao tree is not 



a stationary phenomenon, [t is either rising or falling 

 appreciating or depreciating; and it is obviou 



essary to be certain that all the plots we wish to 

 compare are composed of trees which are metaphor- 

 ically situated on the same point of the curve of 

 productiveness 



From all that has.been said ii will be seen that the 

 present subject is a ver) complex one and calls for 

 clear thinking in thematter ofplanning experiments 

 and in the interpretation of their results. In the 

 Trinidad experiments it is essential to bear in mind 

 that the yield of groups oftrees.and not theyield per 

 acre, is considered. On this understanding, and assum- 

 ing that the trees are strictl) i t parable, the results of 



the manurial experiments following the testing of the 

 cacao trees in their natural state are likely to be the 

 most conclusive, as regards local application, of any 

 that have so far been obtained. 



DEPARTMENT NEWS. 



The Imperial Commissioner of Agriculture has 

 been appointed by his Excellencj the Governor oi 

 British Guiana (Si* Walter Egerton, K. C. M. G.) an 

 honorary memberof the Board ol Agriculture and of 

 the Permanent Exhibitions Committee of that colony. 



\ copj : "t an t Irdinam 



incorporate the Cacao Planters Asso iation ol Trinidad with 

 the object ol regulating and determining the rights and 

 liabilities of the members. It will be interesting to observe 

 the commercial results which follow the passing of the 

 Ordinance. It is worth noting that in this Draft, a bag 

 :acao is defined as weighing 1 ' • -~> lb. 



