and Magazine of the Ceylon Agricultural Society.— April, 1910. 



3(39 



of the tropical sun. In the surface soil of an estate growing 

 a green manure crop, there is a large proportion of the 

 water in the liquid form, as the covering of vegetation 

 reduces the temperature of the surface soil, and 

 prevents the direct penetration of the sun's rays. There- 

 fore, when rubber is growing surronnded with vegetation, 

 its roots have actual access to liquid water through the 

 greater part of the day. If we examine the same soils 

 during the dry season after the green manure crop is dead, 

 we still find more moisture in the latter, as the* dead 

 remains of the green manure crop absorb and retain water 

 more firmly than ordinary soil, but deliver it freely to the 

 rubber roots, although not as freely as to the atmosphere." 



During my recent tour in S. Travancore, I 

 conducted an experiment upon one estate which 

 I visited which exactly bears out the above 

 statement. Two samples of soil were taken, one 

 from under a very poor covering of Passiflora, 

 and one from a patch which had been kept clean 

 weeded and exposed day by day to the baking 

 sun. Equal weights of these samples were dried 

 in an oven for five or six hours and then re- 

 weighed. The result showed that the soil under 

 the Passiflora, though this was of poor growth 

 and gave a minimum of shade, contained 11 per 

 cent, more moisture than that on the clean 

 weeded area, which represents a large amount 

 of water. This experiment is a strong argument 

 in favour of keeping the ground covered with a 

 growing cover crop even during the dry season. 

 A three or four foot circle round each tree 

 should be clean weeded and kept covered by a 

 mulch, and the rest of the land should be 

 covered by a growing crop of Passiflora, or 

 better still of a leguminous weed like Cassia 

 mimosoides. The disadvantage of having the 

 whole soil covered with a dead mulch is the 

 great danger that is run of fire, especially when 

 the estate is surrounded, as it was in this 

 particular instance, by jungle in which fires are 

 constantly occurring. A system of clean weeding 

 which leaves the soil exposed during the dry sea- 

 son to the wind and sun, results in an enormous 

 loss of moisture, far more than is taken out of the 

 soil by a growing cover crop, and this loss, as the 

 above extract shows, it is important to check. 



Apart from this, when the heavy rains of the 

 monsoon period come, the loss of surface soil 

 from wash is very large, and each year this 

 valuable surface tilth is carried away, and the 

 soil is constantly being denuded and impover- 

 ished. A cover crop breaks the force of the 

 rain and prevents this wash. Paddy fields in 

 boundary with some clean weeded estates which 

 receive the wash from the latter, are giving in- 

 creased crops due to the fine surface soil from 

 the estates which is deposited upon them ; a 

 fact which speaks for itself. 



RUDOLPH D. AM STEAD, Planting Expert. 

 — Planters' Chronicle, S. India, March 19. 



THE CINCHONA AND RUBBER 

 BOOMS COMPARED. 



The question may reasonably be asked, says 

 the Chemist and Druggist March 12th, is culti- 

 vation to do for the rubber forests what it 

 has done for the South American cinchona 

 groves? With cinchona we have, after about 

 three decades of cultivation in the East, the 

 drug marketed in more reliable quality at a 

 price which is reckoned in pence, where thirty 



years ago shillings were paid. Then the demand 

 for cinchona was in excess of the supply, just 

 as rubber is now, and, although the total 

 money in it was small compared with rubber, 

 the necessity for cinchona was as great. Cul- 

 tivation of rubber trees in the East and else- 

 where than South America is a modern factor 

 in rubber supply. At present most that the 

 world uses comes from natural forests, and it 

 is not a quarter of a century since there was 

 grave doubt about the possibility of cul- 

 tivating rubber yielding trees in the East. Thus, 

 writing, in the Chemist and Druggist of July 

 23rd, 1887, a Ceylon correspondent said : 



" It is rather remarkable that, considering 

 what a great success cinchona production has 

 been in Ceylon, greater trouble has not been 

 taken with the india rubber tree. The climate 

 suits the plant, and its juice seems to be as 

 free and a plentiful as in Para ; but none of 

 the planters seem to be able to do anything 

 with it. Some years ago thousands of trees 

 were planted, and are still standing, but rub- 

 ber does not yet figure in the exports. 1 am 

 told that the soil ar.d climate are too good, 

 and the foliage gets so heavy as to break down 

 the tree long before the age at which it produces 

 good rubber. But surely if that is really the 

 evil it might be met by careful lopping and 

 proper supports. ' ; 



SYNTHETIC CAMPHOR. 



— is not yet added to the successful achieve- 

 ments of modern chemistry, as a companion to 

 artificial dyes, synthetic perfumes, and a few 

 other products which have made millions for 

 discoverers and manufacturers. The failure of 

 the French Camphor Company has parallels in 

 other countries, and is directly attributed to 

 the Japanese Government reducing the price of 

 natural camphor below the price at which syn- 

 thetic camphor can be produced ; but there is 

 another factor not generally recognised — namely, 

 that synthetic camphor, when used in ward- 

 robes, gives garments a musty odour, which is 

 due, I understand, to traces of impurities that 

 cannot be profitably eliminated. Chemists say 

 that the two kinds of camphor are identical 

 except as regards their optical properties, but 

 the musty residue of the synthetic stuff is 

 as clear a distinction. — Chemist and Druggist, 

 March 12. 



TRINBDAD CACAO AND EXPORTS. 



The adverse effect of black rot (Phytophthora 

 omni'iora) on the yield of cacao is illustrated by 

 the following experiment, which is recorded 

 by Mr J H Hart. In this.diseased and healthy 

 beans were fermented and cured in a similar 

 manner and at the same time. It was found 

 that, while 432 beans from healthy pods weighed 

 1 lb, with diseased pods 565 beans were re- 

 quired to make up the same weight. This cor- 

 responds to a loss of about 25 per cent, with, of 

 course, a lower quality of product,— West Indian 

 Agricultural News,DQc. 11. 



17 



