7IO RUBBER 



by too close planting or from failure to cut out the 

 original shade, more than 4 oz. per annum can scarcely 

 be expected. It must be remembered that on all South 

 Mexican estates the trees were originally planted 400 to 

 the acre, and the only way of improving the yield is to 

 thin them out. Had the trees been planted on properly 

 cleared land 20 ft. by 20 ft., or 109 to the acre, their 

 average yield would no doubt have been much greater. 



I will now return to the old cultivated Castilloas on 

 La Zacualpa, now 27 to 29 years old. They have for 

 some years yielded an average of 2 Ib. of dry rubber per 

 annum, and are expected to continue doing so. But they 

 were originally planted fairly wide apart, and now, owing 

 to cutting out where too close, and to a few deaths, they 

 stand at about the proper distance from each other. 



I should add that the soil of the estates in question is 

 excellent, mostly dark alluvial, frequently 20 ft. in depth, 

 with occasional areas of light sandy soil. The rainfall 

 is about 100 in., seven months rainy season and five 

 months dry. February, March, April, and May are often 

 very dry. In the same locality there are a few other 

 Castilloa plantations with fairly good prospects, but in 

 the other States of Mexico nearly every Castilloa planta- 

 tion- and there are many has been abandoned, or the 

 land turned to other uses. I would not like to suggest 

 how many millions of dollars have been lost in Mexico 

 by inexperienced Americans through planting Castilloas 

 on unsuitable land, but they have been many. The 

 Castilloa is so deceptive. Up to 3 or 4 years old the 

 trees almost invariably look splendid; then the tap root 

 strikes the hard-pan, or the rock, or something else, or a 

 Norther strikes the trees, and they die off. 



The yield of the Castilloa rubber tree compared with 

 that of Hevea must seem ridiculous, say 4 oz. compared 

 with from 2 to 4 Ib. Yet the Castilloa has its points. 

 The actual cost of tapping the trees twice a year is 

 infinitesimal compared with the cost of tapping Heveas 

 from 100 to 200 times a year. There are in Mexico two 

 or three young Hevea plantations, and it is now pretty 

 certain that Para rubber trees will thrive there and yield 

 well. But will labour be available to tap them? I have 



