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average girth per tree is the greatest, i. e. that with 

 wide planting the trees attain a tappable girth quickest. 

 In order to bring the plantation into production in 

 the speediest possible way, therefore, wide planting is 

 advisable. 



We have, however, to take other factors into conside- 

 ration. With wide planting, the total bark-surface is 

 divided over a small number of trees ; less labour is 

 accordingly required for tapping the bark surface, as 

 the work for a large tree is about the same as for a 

 small one, so that, if a double number of trees have to 

 be tapped, in order to deal with the same bark surface, 

 double the amount of labour must be done. We shall 

 see later on that the returns for various planting 

 systems differ less when they are calculated by the 

 acre, than when comparing the productions per tree ; 

 it may therefore be taken that so far as the crop is 

 concerned, a wide planting system is more profitable 

 than a narrow one. 



If, in view of tapping expenses, a wide planting system 

 is advisable, on the other hand, having regard to main- 

 tenance, a narrow planting method may be recommended. 

 The closer the planting is effected, the quicker the plan- 

 tation will close up and close plantations do not, of course, 

 cost as much for upkeep as fields where the soil is still 

 lying open. This objection can, however, be overcome in 

 another manner, with fields which are planted at wide 

 distances, i. e. by planting a catch crop between the rubber. 

 Nearly all cultivations suitable for catch-crops require 

 light and therefore specially require wide planting dis- 

 tances in the Hevea. In planting in rows, there are, 

 between the Hevea, roads of open soil which are well 



