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Mr. E. B. Skinner mentions the following case : 
“ On an area planted 10 ft. by 10 ft. when tapping was 
started there were about 600 trees to the acre, these were first 
reduced to 100 and afterwards gradually thinned out until the 
number was about 60 to the acre. It is interesting to note that at its 
best this area yielded as much as over 900 lbs. per acre, but after 
reaching this point, the area rapidly showed the result of close 
planting and before thinning out began the yield had dropped to 
below 400 lbs. per acre.” 
I might mention at this point that some of the enthusiastic 
advocate of thinning out point to the immediate results as shown in 
the increase of the average yielrl per tree. To some extent this is 
misleading, as if the work has been done in an intelligent maimer 
the poor yielding trees will have been removed, which automatically 
increases the average yield of these remaining. 
Old Clearings. 
The case of old clearings is far more difficult and depends very 
largely on the age of trees. In the ease of very closely planted 
clearings of 12 to 14 years I should recommend the acquisition of new 
land and planting at a reasonable distance. I 1 lie trees can undoubtedly 
be improved, but it will of necessity be a long time before the 
increased yield of the individual trees balances the loss in yield per 
acre caused by the loss in numbers. 
Clearings from Seven to Twelve Years of Age. 
As a general rule, it will probably be found best to reduce the 
number of trees per acre to one hundred during the first selection. 
In this original selection it will probably he possible to pick trees 
and at the same time pay attention to spacing. Deformed trees, 
trees with forked stems, burrs, damaged heads, etc., will, of course, 
be chosen, but at the same time it will be necessary to take out a 
large number of trees which are perfectly healthy. After this the 
trees should be taken by selection and it would be well to mark the 
trees and keep them under observation for some time before cutting 
them out. The following year they could probably be reduced by 
twenty trees per acre and in the next year by ten. 
Experience has shown that 60-67 trees per acre is sufficient in 
the case of 11 to 12-year old rubber. 
Method of Thinning Out. 
Formerly it was customary to pollard trees which it was 
intended to thin out at height of six to seven feet and tap them till 
the trees ceased to yield. Experience lias shown that the rubber 
so obtained scarcely paid for the cost of tapping in addition to the 
danger of introducing a careless system of tapping. It is better, 
therefore, to take the tree right out. The tap root and any large 
