RUBBER PLANTING 107 



give an average of about 150 trees to the acre, whilst 

 in Ceylon the average number is much nearer 200 to 

 the acre. Although different distances are suitable for 

 different soils and situations, it is generally agreed that 

 these numbers are too large for permanent plantations 

 and lead to excessive crowding by about the tenth year. 

 For future planting a distance of 15 x 15 feet may 

 probably be regarded as the absolute minimum, giving 

 nearly 200 trees to the acre without allowing for casualties. 

 Such a distance must ultimately lead to crowding. On 

 the other hand, a greater distance will almost certainly 

 entail reduced yields from a given area during the early 

 stages of tapping. Unfortunately there does not appear 

 to be any conclusive evidence yet published from which 

 a comparison can be drawn between the results of such 

 close planting and those of wider planting, as time goes 

 on. A consensus of opinion points to the greater value 

 of a smaller number of larger and less crowded trees ; 

 and it is at least probable that the crop will be obtained 

 more cheaply from such a plantation than from one 

 bearing a larger number of more crowded trees of the 

 same age. Twenty trees similar to the largest tree at 

 Henaratgoda 35 years old would yield upwards of 

 1000 Ibs. of rubber annually. 600 Ibs. per acre is about 

 the most that can be got from trees on similar soil 

 planted 12 x 12 feet at 25 years of age. The large tree 

 is however probably exceptional, whilst 12x12 feet is 

 certainly too close a distance. In the present state of 

 knowledge it may be thought that a suitable final 



