368 



The ^Supplement to Hk Tropical Agriculturist 



INTENSIVE RUBBER CULTIVATION. 



Mr Norman Thomson, of 2, Princes-garth, 

 Forest Hill, a son of the late Mr Robert Thom- 

 son, head of the Jamaica Botauic Gardens, tells 

 of an interesting secret process for the intensive 

 cultivation of rubber : — 



" An acre of Para rubber costs some £30, in- 

 cluding interest on capital, &c. After a number 

 of years a yield of 300 lb. may be expected, but 

 a crop is unobtainable under five years. A few 

 years ago 100 lb. per acre was considered an ex- 

 cellent yield, but experience seems to justify 

 the planters' optimism in regard to a yield of 

 200 lb. per acre. One of the pioneers of rubber 

 cultivation, my father revealed to me prior to his 

 death a project for rubber cultivation which, if 

 it m^ets with any success, is destined to affect 

 the question of rubber cultivation to a conside- 

 rable extent. I am now arranging to put into 

 execution, on an experimental scale, the system 

 in question, and while the cost per aero, inclu- 

 ding interest on capital, will not exceed £90, the 

 yield in three years will amount to as much as 

 1,000 lb. per acre. 



"In other words, while the capital outlay per 

 acre will be three times greater than is the 

 case with Para cultivation at the present time, 

 the yield will be more than three times as 

 much, and a saving of several years will be 

 gained before the stage of production approxi- 

 mates.'' 



Mr Norman Thomson adds that the system 

 he has in view embodies conditions of scientific 

 cultivation adopted in the case of other tropical 

 cultures with conspicuous success, and that 

 only an intimate acquaintance with certain 

 tropical cultures has made it possible to con- 

 struct a theory in regard to rubber cultivation 

 which he holds, may conceivably revolutionise 

 the rubber industry. — L. <fc C. Express, Feb. 18. 



" CEYLON." 



" RUBBER AND OTHER PRODUCTS ,; 

 is the heading of an article in the London 

 Times Financial and Commercial Supplement of 

 Friday, February 11. We quote the following 

 extract : — 



Prospects for Rubber. 

 The exports of rubber from both Malay and 

 Ceylon, as well as from Southern India, Suma- 

 tra, Java, Borneo, &c., must very soon now 

 increase rapidly. The minimum estimates of 

 shipments have usually been from 25,000 to 

 35,000 tons of raw rubber for the whole of 

 South-Eastern Asia by 1915 ; but this estimate 

 may be increased in view of the recent experi- 

 ence of the large yields of latex obtained from 

 Para trees as they grow older in both Ceylon 

 and the Malay States. One company's planta- 

 tions show results that would point to a much 

 bigger total five or six years hence for all the 

 Eastern planted area then in bearing. For 

 instance, the yield from the 10 oldest Para 

 trees in a Ceylon plantation — trees quite over 

 20 years at least — has averaged 18 lb. per tree 



Eer annum during the past four years, and the 

 est tree gave 25 lb., the poorest yielding 131b. 

 last year. There is, however, no plantation or 



even 1,000 trees so old as these on a single 

 estate in Ceylon, for there were only 750 acres of 

 rubber planted by 1898, 2,500 acres by 1901, and 

 about 10,000 area about the middle of 1904 Now 

 the Ceylon Handbook and Directory for 1909-10 

 gives a total of 184,000 acres of rubber for the 

 island and about 550,000 acres for all Asia, 

 but the Malay States are reckoned by some 

 local authorities to have at least 240,000 

 acres planted and many of the plantations 

 there are much older than any in Ceylon, as 

 shown by the fact that their total annual 

 exports are already more than four times that of 

 Ceylon. The immediate question of interest is 

 that of the probable exportation of raw rubber 

 for 1910, 1911 and 1912, respectively, from 

 Southern Asia under the impetus of the keen 

 demand and high prices now prevailing. 



I VENTURE ON AN ESTIMATE, 



chiefly based on Malayan and Ceylon experience 

 but allowing for what may come from India, 

 Java and other parts of the Eastern Archipelago, 

 including gatherings from indigenous rubber- 

 yielding trees, as follows:— For 1910. ab< ut 

 8,000 to 9,000 tons (worth over £5 5i'0,(>00,; for 

 1911, a total of about 13,500 tons; and tur 1912, 

 about 19,000 tons. It is quite certain that Eas- 

 tern planters can face a considerable fall in 

 present prices with equanimity as tln-y can put 

 their product at a low rate on the London 

 market. The only difficulty will be found in 

 properties bought dearly or over-capitalised. 

 .Later on the real competition will be between 

 Eastern and Brazil and African rubbers, that 

 is when the total production overtakes the de- 

 mand though of this there is no present appear- 

 ance. Those who may be stdl going on planting 

 rubber should consider carefully how the situa- 

 tion may be by 1915-16, in respect of consump- 

 tion versus production. It is remarkable how 

 freely Ceylon-trained planters have gone to the 

 Malay States, India, Burma and all the East, 

 as far as New Guinea (where Para rubber is 

 doing well), and to the Solomon and South Sea 

 Islands as well as to East Africa and the West 

 Indies. [Various products and Area under Culti- 

 vation are then dealt with.— A. M. & J. F.] 



RUBBER AND CLEAN WEEDING. 



The following extract from a recent Circular 

 issued by the Director of Agriculture, Nyasa- 

 land, is reprinted from the Agricultural News : — 



"It has been proceil that the flow of latex from a rubber 

 tree is affected by endosmotic pressure, which practically 

 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 midday and early 

 afternoon. During the heat of the day much water is 

 evaporated by the leaves, and latex flows slowly, but in 

 the early morning and evening water wishes to enter by 

 the root quicker than it is evaporated, with the result 

 that there i3 an internal pressure which helps the flow of 

 latex; therefore iti- practical to assume that there is an 

 intimate connexion 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 come from ? 

 The answer is, from the lower layers or subsoil, 

 by the 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 the day is prin- 

 cipally in the form of water vapour, the water being vapo- 

 rized to a considerable depth by the direct, overhead rays 



