273 



" The results based on the yield per tree, are also given in 

 diagrammatic form for convenient comparison : — 



CACAO MANURIAL EXPERIMENTS, 1903-5- 

 Yield of wet cacao in pounds per tree. 



5 m. 10 115. 15 lb. 20 lb. 25 lb. 30 lb. 32.5 lb. 



1905 i 3 



^^m^^^^^^i^^^^mmmim 



" These experiments differ from those conducted with annual 

 or short-period crops in that the effects are cumulative, the ex- 

 periments are repeated on the same plot of ground and on the 

 same individual trees year after year, and the results of several 

 years have to be taken into account in estimating the effect. 



"The first point which strikes one is that all the manures used 

 have proved beneficial. In the first two periods (1903 and 1904) 

 while the mixture of phosphate and potash, and the dried blood 

 both gave substantial increases in the crop, the combination of all 

 three in 1903 only gave about the same return as dried blood alone 

 while in 1 904 the return was even less where all three were given 

 than where dried blood alone was used. This is anomalous and 

 points to some disturbing influence. 



The position of afi'airs in the third season is interesting and 

 important. Here we find the smallest yield given by the plot 

 receiving no manure, namely, I9i lb. of wet cacao per tree, the 



