AG R I C U LT U R AL B U LLKTI N 
OF THE 
STRAITS 
AND 
FEDERATED MALAY STATES. 
N°- 9*] SEPTEMBER, 1904. [Vol. Ill 
EXPERIMENTAL TAPPING OF PARA RUBBER 
TREES AT THE BOTANIC GARDENS, 
SINGAPORE. 
An account of the history of the Para Rubber trees growing in 
the Singapore Gardens will be found in Bulletin, January 19O3, p. 2 
(Vol. II No. 1) and the following brief notes and results on the work 
now being carried on may be of interest as shewing the nature and 
progress of the experiments. 
It is intended to experiment on about '1,280 seedling trees, which 
were planted in 1886, 1887 and 1888 on very swampy land. The 
outside rows were planted first, and are much the finest trees aver- 
aging 4^ feet against 2h girth (at 3 feet from the ground) for the 
inside trees. The distance of the inside trees, however, has not been 
uniform and in some clumps is only 6 feet apart, and in none more 
than 15 feet — excepting vacancies not supplied. 
So far as the experiments have gone the comparative yield by 
different methods of tapping has been attempted only, and from 
our own experiments, vvc expect to find the best one for giving the 
best results. Of the methods tried the single incision differs from 
all others in respect of flow of latex, i.e. with single incisions started, 
say, 6 feet from the ground, the flow' of latex increases with each 
tapping as the tappings approach to the base of the tree, and the 
latter tappings may be as good, if not the best of all. The result 
however, has not been generally satisfactory. 
With the herring-bone incisions, and its modifications, as is well 
known, the flow of latex increases from a little to a maximum 
yield and then gradually decreases. But the yield of trees varies 
from scanty to copious, and whichever method is adopted the tap- 
ping is affected by rain and excessive moisture. There is also a 
difference in the composition of latex from trees of different sizes, 
e.g. the same quantity of latex gives a much thicker biscuit of 
prepared Rubber from a big tree than a small one, irrespective 
of age. Very probably a big tree is capable of transpiring exces- 
sive moisture, quicker. 
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