Mr. E. B. Skinner mentions the following case : 



" On an area planted 10 ft. by 10 ft. when tapping was 

 started there were about 300 trees to the acre, these were first 

 i-educed to 100 and aftei^wards 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 

 i-eaching 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 

 advocates of thinning out point to the immediate results as shown in 

 the increase of the average yield per tree. To some extent this is 

 misleading, as if the work has been done in an intelligent manner 

 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 case of very closely planted 

 clearings of 12 to 14 years I should recommend the acquisition of new 

 land and planting at a reasonable distance. The 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 be 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 ti-ees 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 has 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 i-ight out. The tap root and any large 



