24 



eastern aspect. The first effect of close planting is noticeable in 

 the exaggerated upward growth of the trees, which, finding that their 

 branches if extended laterally meet with the branches of neighbouring 

 trees, attempt to overtop their neighbours with the result that their 

 branches are drawn upwards, giving the trees the appearance of 

 bundles of birch twigs. 



Food that could be utilized in the thickening and rounding out 

 of the trunk is used to build up length of branches and trunk, 

 because, in the struggle for sunlight, each tree tries to overtop its 

 neighbour. In consequence, an activity of no profitable use to the 

 planter is induced. By giving the tree more space it will grow 

 outward as well as upward and in a normal, evenly distributed 

 growth. Let it be emphasized that thinning out to be most 

 beneficial should be done before the " drawing up " stage has set 

 in. Very little lateral branching will be induced in an old tree 

 whose early environment has been an overcrowded estate. 



I do not think it necessary to say anything further regarding 

 the effect of sunlight on the branch growth. The effect on the depth 

 of bark is equally noticeable and although it does not follow that a 

 thin bark will necessarily yield less latex than a thicker bark it is 

 extremely probable that coolies in getting the latex will touch the 

 cambium and cause wounds over which the renewed bark will be 

 poorer still. We may, therefore, take it as granted that a tree which 

 has room for normal development as regards branch growth will 

 prove more healthy than that which is retarded and that as a 

 corrollary the yield from such a tree should be greater and the 

 bark renewal better. 



The second point is the great economy which is effected. The 

 unit which is genei'ally taken as a basis of all calculations is the 

 yield per acre. If you can get a high yield per acre fi'om a compara- 

 tively small number of highly yielding trees it is obviously more 

 economical than if you got the same yield per acre from a closely 

 planted estate. I think I may take a yield of 450 lbs. per acre as one 

 likely to satisfy directors and shareholders, and to make every point 

 quite clear we will take a suppositionalcase of two estates of 500 

 acres, one of which is planted with 80 trees to the acre and one with 

 160 trees to the acre — other factors being the same — a reasonable task 

 being 400 trees per cooly. With a check-roll average of 40 cents 

 the cost of collecting will be : 



A. 100 coolies X 350 days x 40 cents _ say, 6,2 cents per lb, 



225,000 - Labour only 



B. 200 coolies x 350 days x 40 cents „, • i i i 

 225 000 "" Twice the above 



It has often been argued that in a widely planted clearing coolies 

 would not be able to do the same task. In practise this is not the case, 

 the woi'k of tapping and collecting takes up the time, not the distance 



