December, 1908.] 



529 



Edible Products. 



market in Manila. As a matter of fact, 

 so far as the cost of production goes, 

 it is probable that industrial alcohol 

 made from manioc could be placed on 

 the Manila market in competition with 

 kerosene, and still be profitable. 



In view of the size and steadiness of 

 the world's starch market, we believe, 

 as already stated, that the best present 

 commercial use of manioc is as a source 

 of starch; but the local market for 

 alcohol is valuable as a guarantee that 

 no crisis in the starch market and no 

 increase in production will jeopardize 

 Philippine investments in manioc. 



{To be continued.) 



THE QUESTION OF SHADE IN 

 COFFEE CULTIVATION AS 

 APPLIED TO CACAO. 



The great importance attached by our 

 readers to the question of shading cacao, 

 as shown by the conversations and cor- 

 respondence that grew out of the paper 

 read by our Editor at the Colonial Fruit 

 Show of the Royal Horticultural Society, 

 has also led up to the advisability of 

 shading coffee as well. As the circle 

 that gathered at the Fruit Show broke 

 up before we could look up our notes 

 on the matter, we now publish them 

 and shall be only too glad if those who 

 took part in the preliminary debate in 

 London will continue the discussion in 

 our columns. 



With all crops, the question of shad- 

 ing need not only refer to the protection 

 of the plants or trees from the sun, but 

 to the protection of the soil from the 

 effects of too much heat or heavy rains. 

 " Leguminous shade trees," Colville tells 

 you, " in addition to the effects produced 

 by shade trees in general, also protect 

 the soil from erosion, drying, and 

 heating ; and, in preventing the mecha- 

 nical injury of the coffee plants by the 

 wind, have a beneficial effect on coffee 

 .... by adding nitrogen to the soil and 

 thus, without expense, increase the 

 fertility and productiveness of a planta- 

 tion This Central American sys- 

 tem of shading coffee was adopted from 

 the customs of the Aborigines in the 

 shading of cacao in prehistoric times, 

 which is still practised in many local- 

 ities. It is confidently believed," he 

 adds, -'that a rational system of coffee 

 culture in Puerto Rico, based on the 

 use of leguminous trees and plants for 

 shade and fertiliser purposes, will 

 revolutionize the coffee industry in that 

 island, and at least double the yield per 

 acre." This was written eight years ago, 

 in December, 1900. 



67 



"Testimony in favour of shade," Mr* 

 O. F. Cook tells you,* "has come almost 

 entirely from Central America, Vene- 

 zuela, and Colombia (which would, we 

 take it, include the West Indies), in 

 which region the custom of planting 

 leguminous trees with coffee is general ; 

 in Brazil and in the East Indies, where 

 experiments have been made with figs 

 and other non-leguminous trees, theory 

 and practice have generally ignored or 

 directly opposed the use of shade. These 

 contrary ideas are reconciled by observ- 

 ing that the coffee and cacao planters 

 of the Central American region have 

 been practising unconsciously a system 

 of soil fertilization. .... the leguminous 

 trees being able to avail themselves of 

 the atmospheric nitrogen by means of 

 their root tubercles and attendant bac- 

 teria. ... If the increased fertility of 

 the soil through leguminous trees be 

 left out of account, the adverse opi- 

 nions of Dafert and other scientists must 

 be admitted as justified, and shade 

 must be condemned as a cultural error 

 of huge practical dimensions. . . . There 

 are soils and climates where shade trees 

 are unnecessary, or even harmful, but 

 in broken and mountainous regions, and 

 in arid regions, where a great extension 

 of the industry is possible, leguminous 

 trees have, and will doubtless continue 

 to have, enormous agricultural import- 

 ance." 



This is written, of course, in reference 

 to coffee, but can equally well be applied 

 to cacao, which requires nitrogen to an 

 even greater extent than coffee. Where 

 the difference of opinion as to the 

 utility or disadvantage of shade trees is 

 so difficult to reconcile, is in steep, hilly 

 lands, and as many cacao estates or 

 at least part of them, are spread over such 

 lands, the question is for ever cropping 

 up afresli. Against the use of shade 

 trees in hilly or mountainous regions, 

 as recommended by Mr. Cook, can be 

 advanced the disbelief of the Grenada 

 planters (whose estates cover some very 

 hilly areas) in the utility or advantage 

 to the cacao. Should it become a more 

 general practise to apply manures and 

 fertilisers to cacao trees, the decision 

 as to the advantage of shade trees (of 

 leguminous annual varieties), planted 

 with the cacao might be modified. So 

 also might the idea of planting legu- 

 minous trees among the cacao to hold 

 the soil, and in order to discourage 

 weeds, retain moisture, to render the 

 soil more fertile by adding nitrogen to 

 it, and to protect the crop from the 



* "Shade in Coffee Culture," by O. F. Cook. 

 Bulletin No. 25, United States Department of 

 Agriculture, 



