COCOA 203 



be followed is to select carefully the required number 

 of plots, and ascertain beforehand the natural yield of 

 each plot for three or more years. This is being done 

 in Trinidad, and Table F (p. 211) affords further proof of 

 the great variations in the natural yield obtained from 

 adjacent and carefully selected plots on different estates 

 in various parts of the Colony. The yields from these 

 plots are ascertained by the managers of the estates, who 

 co-operate with the Department in carrying out these 

 experiments. 



Similar results have been obtained from plots on the 

 estate owned by the Government, as shown in Table D. 

 Here in Plot 9 the yield is nearly three times that in 

 Plot i. 



The ten plots in this field are adjacent to each other, 

 the total area does not exceed two acres, the trees are 

 of the same age, the soil is to all appearances the same 

 in each, and an analysis of the soil in five of the plots has 

 shown that the chemical composition is practically the 

 same in all. The results of the analysis are given in 

 Table E (p. 210), and in this will be noticed a somewhat 

 larger percentage of pebbles and sand in some plots, but 

 the difference is insignificant in a soil of this character. 

 The only conclusion that can be drawn from these tables 

 is that the different yields from these plots cannot be due 

 to any difference in the chemical composition of the soil. 



Table G (p. 211) gives the yield from control plots on 

 estates for two consecutive years, 1911-12 being a year of 

 great drought, during which a large number of trees 

 and especially young trees died from insufficient rainfall, 

 and a still larger number suffered considerably, and 

 1912-13, a year of nearly normal rainfall, during which 

 some of the trees* injured by the previous year's drought, 

 had not completely recovered. The effect of the drought 

 on the young trees is strikingly shown in the California 

 district. But even under such unequal conditions of rain- 

 fall the greatest increase in yield has not exceeded 35 per 

 cent., and in other cases the increase or loss in yield has 

 been small in comparison with the difference in yield from 

 different plots. 



The three control plots in Field i at River Estate have 



