CHAPTER IV 



SOIL REQUIREMENTS OF THE COCOA TREE 



The Chemistiy of the Cocoa Tree. — As the cocoa tree 

 is mainly dependent on the soil for its nutrition a 

 consideration of its chemical components will afford 

 an indication of its requirements in this respect. The 

 chemistry of the cocoa tree has been investigated by 

 Harrison in British Guiana, Cockrane in Ceylon, Marcano 

 in Venezuela, and Jumelle furnishes valuable data of 

 this nature in his book Le Cacaoyer. 



Jumelle gives the following ash analyses of a cocoa 

 tree twenty years of age. 



Cockrane found by his investigations in Ceylon that 

 the trunk and principal branches represent 50'2 per cent., 

 leaves and small branches 36' 6 per cent., and the roots 

 13" 2 per cent, respectively of the whole tree. He 

 found the proportion of organic matter to be highest 

 in the beans, trunk, and principal branches, and lowest 

 in the leaves and fruit-shells ; also the highest percentage 

 of nitrogen in the beans and lowest in the stem, and the 

 ash constituents lowest in the beans and highest in the 

 leaves, small branches, and fruit-shells. His analyses of 

 the ash of the cocoa tree are as follows : 



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