3^2 SCIENCE IN AFRICA 



Dahomey, for example, fruits at present consist on the average of 

 some 30 per cent oil-bearing pericarp, 20 per cent kernel, and 

 50 per cent shell, and it is hoped to alter the proportions to 60 

 per cent pericarp, 20 per cent kernel, and 20 per cent shell. 

 Opinions differ on the relative merits of introduced Deli palms 

 and selected indigenous varieties. Nearly all the oil is expressed at 

 present by primitive methods. A few years ago a large mechanical 

 press was set up in Dahomey by the Compagnie Fran^aise, but its 

 working has closed down because the peasant producers preferred 

 to express their own oil. There are, however, some thirty machines 

 for cracking the nuts for the extraction of the kernels now in use 

 in Dahomey, and in the Ivory Coast mechanical presses, mounted 

 on lorries which move from village to village, were introduced in 



1930. 

 In the Belgian Congo the largest oil-palm plantations are those 



of Unilever, situated in a zone extending from about 5° N. to 

 5° S. L. Conrotte (1935) has published an account of the funda- 

 mental technical principles recommended; this deals with methods 

 of soil selection, the establishment of seed beds and nurseries, cul- 

 tural methods in the plantations, types of cover crops, the symp- 

 • toms of the most important diseases and appearance ofthe principal 

 insect pests. In addition to the creation of new plantations much 

 work has been done in the improvement ofthe 'natural' palmeries 

 — which may be abandoned native plantations — by thinning and 

 replanting. Imported seed has here been found unsatisfactory, 

 and breeding is based on indigenous varieties. Plantation methods 

 are being studied with a view to securing the most advantageous 

 conditions for the growth ofthe palm, while permitting the exten- 

 sion of plantation with the minimum of labour. Studies on seed 

 selection and on other aspects of the biology of the oil-palm have 

 been published by A. Beirnaert, director of the Yangambi experi- 

 mental station (1933 and 1935) and the causes of acidification of 

 the oil have been investigated by R. Wilbaux (1936). 



The coconut {Cocos nucifera) is grown in plantations, chiefly near 

 the sea. The dried kernel of the ripe nut, known as copra, is an 

 important article of trade; the oil expressed from it is used for 

 margarine and soap, and the refuse is made into oil-cake for feeding 

 cattle. In British East Africa, apart from Zanzibar, the industry 



