'278 



The Supplement to the Tropical Agriculturist, 



In Brazil, matters were quite different, said 

 Mr Sandmann, as they smoked their rubber, 

 and that acted as a disinfectant. That system 

 would, however, be impossible to work here 

 with large quantities of latex. It was easy 

 enough in Brazil, because each seringuero only 

 had a small amount to deal with at a time. For 

 this country he advocated the use of Purub, 

 a preparation of hydrofluoric acid, instead of 

 acetic acid. The results from this were very good 

 as the preparation did not attack the rubber 

 in any way, whereas acetic acid had its bad 

 qualities. For instance, when it was used, fer- 

 mentation and oxidation continued after treat- 

 ment, whereas with Purub such fermentation 

 and oxidation were impossible. The method was 

 simpler in working and produced rubber of a 

 wonderful quality. He was exhibiting a speci- 

 men at the Penang Show. 



Questioned further as to what other of our 

 methods he considered might be improved upon, 

 Mr Sandmann mentioned briefly that he had 

 noticed cases here where trees had been topped 

 to get more branches. This was a mistake, as 

 the branches then became too heavy, and were 

 liable to break during heavy weather. 



Coming to the subject of 



PESTS, 



the informtion was that in Brazil they expe- 

 rienced no trouble from white ants, their 

 chief enemy being the boring beetle. Tappers 

 there, on noticing holes, drove in plugs, thus 

 causing the insects to die of starvation, Asked 

 as to whether he considered that we had much 

 to fear from white ants here, Mr Sandmann re- 

 plied that he thought we should have to be very 

 careful, but that, if due caution were exercised, 

 we ought to be able to keep these pests at bay. 

 He did not anticipate any other serious trouble 

 and our plantations looked very sound. The 

 question of distance in planting was then alluded 

 to, and Mr Sandmann expressed the opinion that 

 our planting was frequently too close. If he were 

 opening an estate, he would plant not more than 

 from 120 to 150 trees to the acre. 



Finally, Mr Sandmann expressed his convic- 

 tion that we had a wonderful future before us. 

 There was no fear, he said, of overproduction in 

 this generation at least. Even if the output 

 reached 200,000 tons, as compared with the pre- 

 sent 70,000, rubber would still pay well, though, 

 of course, at a much lower figure. 



Gutta-Pbkcha. 



In the course of conversation, Mr Sandmann 

 mentioned that he had been making some ex- 

 periments, in conjunction with Mr Derry, at 

 Singapore, in an endeavour to obtain good re- 

 sults from jelutong, our wild getah. In this 

 they considered that they had been successful, 

 and they hoped to be able to get this product 

 brought into increased use. Up to the present 

 the difficulty had been that it had not been 

 found possible to coagulate the matter in such 

 a way as to get it clean ; but now, by their pro- 

 cess, the getah could be coagulated with very 

 little foreign matter. The world's supply of 

 gutta-percha was very limited, said Mr Sand- 

 mann, but there appeared to be plenty in 

 Malacca, and a still larger supply in our new 

 territory up north. Para rubber had nothing 

 to fear from this, as its uses were quite different, 

 w-Jtfalay Maily Aug, 10. 



THE EFFECT OF GREEN MANURE 

 ON RUBBER. 



Mr. J.Stewart J. McUall, Director of Agri- 

 culture, Nyasaland. who will be remembered a6 

 a recent visitor to Ceylon, has just issued an 

 oflicial circular dealing with green manuring in 

 the tropics. One section of his paper deals with 

 the " Effect of Green Manure on Rubber," and 

 from it we quote as follows : — " It has been 

 proved that the flow of latex from a Rubber tree 

 is affected by endosmotic pressure which practi- 

 cally means the amount of water in the plant 

 roots. It is the practice to tap Rubber in the 

 early morning and evening, and to discontinue 

 during the heat of mid-day and early after- 

 noon. During the heat of day much water is 

 evaporated by the leaves and latex flows slowly, 

 but in early morning and evening water wishes 

 to enter by the root quicker than it is evaporated 

 with the result that there is an internal pres- 

 sure which helps the flow of latex; therefore it is 

 practical to assume that there is an intimate 

 connection between the presence of water in the 

 surface soil surrounding the roots, and the flow 

 of latex from the Rubber tree. For half the 

 year in Nyasaland there is no rain, and daily 

 the sun is strong enough to evaporate water 

 from the plants, and from the soil. The question 

 arises where does this water com e f rom 'i The an- 

 swer is from the lower layers or subsoil by rising 

 to the surface in the form of water vapour and 

 water liquid (capillarity). In the surface soil of 

 a clean weeded estate the water during day is 

 principally in the form of water vapour, the 

 water being vaporised to a considerable depth 

 by the direct overhead rays of the tropical sun. 

 In the surface soil of an estate growing a green 

 manure-erop there is a large proportion of the 

 water in the liquid form, as the covering of vege- 

 tation reduces the temperature of the surface 

 soil and prevents the direct penetration of the 

 sun's rays. Therefore when Rubber is growing 

 surrounded with vegetation, its roots have ac- 

 tual access to liquid water through the greater 

 part of every 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 delivers it freely to the rubber 

 roots although not as freely to the atmosphere.' 1 



THE F.M.S. AGRICULTURAL SHOW. 



Teemes Species oh Ants. 



Previous to their departure for Penang, we 

 have been afforded an opportunity of seeing the 

 exhibits of the F. M. S. Agricultural Depart- 

 ment that are to appear at the forthcoming 

 Agri- Horticultural Show. One of the principal 

 features will be a series of long tablets on which 

 will be arranged glass tubes containing speci- 

 mens of the various kinds of the termes species 

 of ants. The king, the queen, winged indivi- 

 duals (mature and immature), soldiers, workers 

 and young — all will be represented, while their 

 nests will be shown apart, but adjoining. In 

 addition, a brief description of each species will 

 be' found written at tho bauo of the tablets, 



