and Magaztne of the Ceylon Agricultural Society,— December, 1911. 569 



YIELDS FHOM YOUNG AND OLD 

 RUBBER TREES. 



Hitherto it has been impossible to give any- 

 thing like an adequate survey of the yields 

 likely to be obtained from Hevoa trees under 

 cultivation in the Middle East. Now, however, 

 we have detailed information regarding results 

 obtained during the last six years from trees 

 ranging in age from 2£ to 25 years of age, grow- 

 ing under very dissimilar eond'tious and tapped 

 on systems remarkable for their variability in 

 principles. We now possess records of yields 

 from exceptionally young and old trees, from 

 trees with a difference of twenty years in age, 

 from individual estates, and lastly from the whole 

 of the tapped trees in the peninsula during 

 specified years. 



Yields from Young Trees in Malaya. 



The yields obtained during the last five years 

 in Malaya have been largely responsible,for stim- 

 ulating interest, agriculturally and financially, 

 in the rubber planting industry. There are now 

 about a hundred London companies producing 

 rubber in Malaya alone, and the yields obtained 

 over large acreages as well as from notable trees 

 have so far given every satisfaction. 



The yield from very young trees is by no means 

 insiguificant. An experiment was made in Selan- 

 gor during 1909 with 2,845 trees which w^re only 

 2| years old ; these were tapped for two months 

 and gave an average yield of 0"297 lb. per tree. 

 Tapping for only eight mouths 2,843 trees, 3^ 

 years old, gave 1'24 lb. per tree, and in nine 

 months 6,426 trees 3| years old gave 1'06 lb. 

 per tree. 



Another record shows that 6, 444 trees 4§ years 

 old gave, in two months, 0*178 lb. per tree, and 

 4,420 trees, 5J years old, for the same period 

 yielded 248 lb. of rubber. In another field, 

 400 trees, 4f years old, tapped for six months 

 gave 1 107 lb. per tree, and 4,674 trees 

 5| years old, during the same period returned 

 an average of 0'961 lb. per tree. 



A large number of trees, all 5J years old) 

 were tapped during 1909 for two, four and six 

 months, and yielded respectively 248, 0'503 

 and 0"997 lb. per tree, or an increase of approxi- 

 mately 50 per cent for each two months' tapping. 



We have already pointed out that other 

 advices from the East have been received which 

 show that some trees 3^ to 4.$ years old in the 

 Straits Settlements and in Klang have given at 

 the rate of nearly one lb. of rubber per annum 

 per tree. The bark of these trees is relatively 

 soft and does not compare favourably with the 

 harder texture of that on trees which have 

 taken a longer time to attain the tappable size. 



Excellent results have been obtained on 

 Malay estates by cutting a large V or Y at a foot 

 to eighteen inches from the base of the tree, the 

 V extending half round the tree; when the tree 

 is large enough a second V is cut on the reverse 

 Bide. By such a method the young trees can be 

 tapped regularly— almost every alternate day — 

 the rubber is extracted only from the thick part 

 of the bark, and a high yield is obtained from 

 the basal regions. 



From old Trees 

 In marked contrast with the above are the 

 unexpected high yields obtained, in twelve 

 months, from individual trees on various pro- 

 perties. On Jugra estate we are informed that 

 seven to nine year old trees gave seven lb. per 

 tree, and on Cicely eight-year-old trees gave 8 

 lb. The Federated Malay States Company pos- 

 sess over 2,900 9J-year-o!d trees which gave 

 24,000 lb. of rubber in one year, or an average 

 per tree of 8'2 lb. Twelve-year-old trees on 

 Liinggi yielded 10'7 lb. in twelve months, 

 Batu Unjor is reported to have secured 

 i0 - 73 lb. per tree from 6,800 trees at the 

 age of from 11 to 12 years, A yield of 

 28i lb is also recorded from the 17-year-old trees 

 growing near the churchyard at Farit Buntar. 

 Similarly high yields, equal to one pound of rub- 

 ber for each year's growth have been published 

 from time to time, but it is extremely doubtful 

 whether such yields can be relied upon annually. 

 In several instances the trees have been growing 

 under exceptionally favourable conditions, and 

 many do not appear to have been tapped until 

 they attained quite an advanced age. 



Yields in Ceylon. 

 It is quite manifest from a comparison of the 

 figures available in this office that, up to the 

 present, Ceylon takes a second place compared 

 with Malaya, in point of annualyield from young 

 trees and from definite acreages of known age. 

 It so happens that the yields from old trees in 

 Ceylon are exceptionally high. It is neverthe- 

 less, clear that the soil or climatic conditions in 

 Ceylon are less favourable, in the first few years, 

 to the growth of Hevea brasiliensis. Whether 

 the moist conditions in Malaya will prove to be 

 as beneficial to old trees as the dry environment 

 in Ceylon remains to be proved. It must be 

 pointed out that, though the rubber in Ceylon 

 may only have been produced at the rate of 

 150 lb. per acre, per annum, other products on 

 the same land have returned good crops during 

 the same period. 



From Young Trees. 

 There are very few, if any, estates in Ceylon 

 where the trees are sufficiently large to permit of 

 tapping under four years of age. In this respect 

 there is a striking difference with Malaya, where 

 tapping is often started as soon as the trees are 

 three years old. Purely as an experiment some 

 two-year-old trees were tapped in Kalutara, but 

 the yield therefrom was insigni6cant. In this 

 district quite a number of trees, tapped when 

 four years old, have given over 100 1b per acre 

 in the first twelve months. A yield of £ lb. per 

 tree is recorded from 2,119 trees, four years old, 

 on the estate, and of 0'63 lb. per tree from 747 

 trees at the same age on Mahawale. On Rayigam 

 6,000 trees, four to five years old, gave ^ lb of 

 rubber each, and a further 1,500 yielded 0-41 lb, 

 each. Light tapping of young trees on a well- 

 known Kalutara propeity gave 1*72 lb. of 

 rubber per tree. 



From Old Trees. 

 At one time a yield of two to three lb. per tree 

 from eight to eleven-year-old trees on Kepiti- 

 gala estate was considered good. One tree on 

 Elpitiya, 46 inch in circumference and eleven- 



72 



