THE FUTURE OF CACAO PLANTING. 



195 



mulching has been composted by adding lime or basic slag, which helped 

 to liberate large quantities of plant-food which might otherwise have 

 remained unavailable. The addition of basic slag or similar fertilizing 

 matter has, further, the advantage that it makes good the deficiency 

 of the compost in phosphoric acid, and thus assures that the other 

 fertilizing ingredients in the compost are well balanced. 



According to Bert de Lamarre (Trinidad), pen manure for cacao trees 

 is exceedingly good, although it does not contain enough phosphate of 

 lime to form the skeleton of the tree and not enough potash. It is 

 principally due to the absence of or want of sufficient phosphoric acid, 

 lime and potash, that so many young flowers and pods drop at a time, 

 not having the necessary strength to resist the wind and weather. The 

 condition of the tree in these circumstances is an abnormal one, having 

 flowers in quantity, but wanting the necessary elementary material in 

 circulation to produce what such trees are capable of, if well and normally 

 fed. The presence of fungoid pests on cacao trees is partly due to the 

 want of strength of the trees to resist the diseases caused by living 

 parasites, animal and vegetable, and potash in good quantity should be 

 supplied. 



When land is not pen-manured or requires to be pen-manured again 

 the best and cheapest plan is to plant strips of sweet potatos, in cane- 

 fields when the canes are planted, and in cacao-fields at any time, and to 

 let them grow until immediately before throwing out tubercles, when 

 they should be buried, root and stem, in the soil. 



I mention sweet potatos as they are well known here, but perhaps 

 some people may not know the woolly pyrol, which is grown in Barbados 

 and has the advantage of not being edible, as is the case with ordinary 

 sweet potatos, which sometimes, when the growth is quick, cannot be 

 buried before the product is exposed to the usual pilfering. 



Green manure, or green dressing by sweet potatos, woolly pyrol, or 

 American peas is one of the best available sources of nitrogen that can 

 be offered to plants, and it is advisable to employ green dressing and 

 to manure in this way wherever possible. 



One of the most important fertilizing ingredients for the cacao tree, 

 but at the same time the most costly, is nitrogen. Fortunately, how- 

 ever, we have the leguminous plants which absorb the atmospheric 

 nitrogen, and which, used as green manuring, could easily supply the 

 cacao tree with its nitrogenous requirements. Would it not pay to 

 cultivate ground nuts (Arachis hypogaea) or some other leguminous 

 crop that would grow under shade in order to have material rich in 

 nitrogen at hand for mulching between the trees ? Would it be possible 

 to grow it sufficiently well under the cacao to produce the nodules 

 underground ? If cultivated as a crop for the oil the cake is still of 

 great value, as it contains 1\ per cent, of nitrogen, whilst the leaves 

 have 1 per cent. 



"Farmers' Bulletin" 815 (January, 1908) of the United States 

 Department of Agriculture, commenting on the inoculation of soils or 

 seeds with pure bacteria cultures, states that, in some cases where there 

 has been apparent failure to improve the legume crop, further examina- 

 tion may show a decided gain from inoculation. Even where the lack 



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