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be applied in this process of selection. It is the choice of rapid 

 growing, healthy plants of a certain desirable type. It is of the 

 greatest value to the planter to have trees which are as rapid 

 growing as possible. Now with the transplanting system a certain 

 amount of selection can be done, but this is before the trans- 

 planting process, during which the plant is always more or less 

 injured. There is no selection possible after the transplanting. 

 With the " at stake" planting system mentioned we do our most 

 important selection after sowing the seeds. I will presently refer 

 to the selection which precedes the planting. 



With the growth of the young rubber trees, successive thinnings 

 become necessary to prevent crowding. It is here the men in 

 charge of the plantation have to exercise their best judgment. 

 We fully realize the necessity of plenty of air and light for the 

 growing tree. If this is neglected the whole system naturally is 

 detrimental. But there is no reason why such an important matter 

 should be overlooked. We have presupposed that we have to do 

 with intelligent planters and superintendents, who realize that 

 rubber growing on scientific and profitable commercial lines is a 

 shade different from potato growing, as our forefathers practised 

 this necessary and honourable industry a century ago. 



On La Zacualpa we thin the rubber stand several times every 

 year until the third year, when we have approximately 800 trees 

 to the acre. During the fifth year we tap fifty per cent, of these 

 trees, selecting the poorest and leaving the best trees untouched. 

 We tap heavily, that is, extracting as much latex as is possible. 

 A few weeks later the trees are inspected. Those that have 

 suffered from the tapping are marked and doomed. If they still 

 yield latex they are cut up with numerous incisions, and a few days 

 afterwards the scrap is collected and the trees felled. Those trees 

 that promise to recuperate are left untouched for four months, 

 when they are again tapped in the regular way. After a second 

 inspection they are killed. Exceptional trees which do not crowd 

 upon the permanent trees may be left to the following, or sixth 

 year, when they are tapped with an ultimate view to their 

 destruction. At the end of the sixth year we have 400 trees to the 

 acre. 



Many objections have been raised against this method of close 

 planting and successive thinnings. The main point in question 

 seems to be whether the cutting out of a number of trees, leaving 

 stumps with the roots in the ground, would not be preparing 

 breeding places for fungous or insect diseases. I admit that 

 there is some truth in this objection. In talking about rubber plant- 

 ing I am fully aware of the many dangers that may and most likely 

 will arise from pests, animal or vegetable, in our Castillo, or other 

 rubber plantations. But in endeavouring to find preventives we 

 must first of all be practical. Methods that are impossible to 

 realize in practice are not worth mentioning. 



If we are afraid of leaving the roots of rubber trees in the 

 ground, why do we leave the roots and stumps of the jungle trees 



