November, 1909.] 



387 



GUMS, RESINS, SAPS AND EXUDATIONS. 



Extracts from the Report of the Direc- 

 tor of Agriculture for the Federated 

 Malay States. 



(From the Agricultural Bulletin of 

 the Straits and F. M. S„ Vol. VIII., 

 No. 9, September, 1909.) 



Rubber Tapping, 

 The Rubber Curing House was com- 

 pleted during the year, and machinery 

 for curing rubber, consisting of an oil 

 engine, a roller and a hydraulic press 

 have been obtained. 



There are 900 trees of over nine years 

 old, on which a series of experiments 

 will be made and all data recorded. 

 Many problems of great economic im- 

 portance await solution. The climate of 

 Malaya differs so greatly from that of 

 Ceylon and other rubber-growing count- 

 ries, that the results of experiments 

 carried on there cannot with safety be 

 used as giving reliable information for 

 treatment of trees in this country. 



The whole question of tapping re- 

 quires careful investigation. The re- 

 sults given by thin paring of cuts at an 

 angle to the axis of the tree are so good 

 that planters are apt to consider the 

 matter solved, but it is not improbale 

 that punctures instead of cuts may yet 

 be found to give as good or better yields 

 and involve less skilled labour- All the 

 " prickers " which have up to the present 

 been exploited are instruments not for 

 making a puncture but a short deep cut, 

 and consequently damaging relatively 

 more cells of the tree than a cylindrical 

 or sharply conical pricker. There is a 

 large field for ingenuity and careful ex- 

 periment ; and the next few years should 

 produce an instrument which will be 

 a marked improvement on the present 

 weapons. 



Excellent work with regular shavings, 

 as thin even as 20-25 to the inch, have 

 been done with the gouge, the Farrier's 

 knife, and with more modern specially 

 adapted tapping knives. 



It is important to make certain of the 

 periods which should be allowed to 

 elapse between tappings in order to get 

 maximum yields. After having collected 

 figures of yields on a large number of 

 estates, it is difficult to lay down an ab- 

 solute rule as to the procedure which 

 experience shows to be the best. 



Carefully kept data on some estates 

 show that after a period of some three 

 months alternate days' tapping the 

 amount of latex per tree decreases to an 



49 



amount which is of less value than the 

 cost of tapping, but after a rest of two 

 months the tree again on the fourth or 

 fifth tapping yields the maximum, which 

 after some forty tappings begins to 

 rapidly decrease. 



The reverse of these observations is 

 to be found on other estates where accu- 

 rate figures of yields show that after 

 continuous tapping for some two or 

 three years, the amount obtained varies 

 only slightly, never steadily decreasing. 

 The variation is caused by climatic 

 conditions, short periods of little or no 

 rainfall reducing the yield, and periods 

 of excessive rainfall producing some- 

 what the same result. This is due to the 

 relatively less active functioning of the 

 roots owing to drought or excess of 

 water. 



Many planters believe in stopping- 

 when the trees are leafless, a period of 

 some three weeks each year. The ex- 

 periments which have been continuously 

 carried on for some eighteen months by 

 this department on 17-year old trees at 

 Krian show a slight decrease of yield 

 during the leafless period. 



The notion is also prevalent that 

 tapping should be discontinued during 

 the fruit-bearing period- The figures 

 obtained at Krian show a decrease 

 during the time the trees were in fruit, 

 but no sufficient decrease to seriously 

 increase the cost of tapping. The figures 

 relating to these tapping experiments 

 will be published in the "Agricultural 

 Bulletin." 



Careful records have been kept of the 

 weight and bulk of latex each day from 

 each tree, and the ensuing weight of 

 dry rubber. 



The question of how far it is advisable 

 to refrain from tapping rubber trees 

 after a period of tapping is one upon 

 which planting opinion differs very 

 greatly. On some estates, after a period 

 of some weeks or months of tapping, a 

 period of about equal length is allowed 

 to elapse without tapping. On others 

 and the majority of places tapping is 

 continued without cessation, in some 

 cases trees having without any reduction 

 of yield been tapped for 3i to 4 years 

 every other day without cessation. On 

 the question of daily or alternate days' 

 tapping planters are also divided, and 

 experience of yields points somewhat to 

 the advantage of the latter practice. 



There is no physiological reason why 

 the tapping should cease during the leaf- 

 less or fruit-bearing period ; the cutting 



