76 CENTEAL AMEEICAN EUBBEE TEEE. 



in Europe as the most authoritative work on the subject, states that 

 vigorous 8-year-old trees will yield without injury something over a 

 pound of rubber from three tappings, but he gives no intimation that 

 this represents an average of any considerable number of planted 

 trees, and, while he claims that his rubber gatherers have secured as 

 high as 3f pounds from wild trees eight or nine years old, the uncer 

 tainty in the age of wild trees prevents such figures being relied upon, 

 as he himself admits in another place. 



This uncertainty of the time factor greatly reduces th-e value of 

 figures derived from wild trees, particularly if complicated with other 

 variable elements. The quality of rubber is known to differ with the 

 age of the tree, and the same may be true of the quantity. The size 

 of a forest-grown tree is no indication of its age as compared with one 

 grown in the open. Wild trees are subjected also to an amount of 

 cutting which nobody would advocate for planted trees. If the trees 

 at La Zacualpa had been ascended w T ith ladders and the whole trunk 

 tapped, twice as much rubber or more might perhaps have been 

 secured, or say 4 or 5 pounds at a more favorable season, but such an 

 extension of the wounds of the trunk might be too much for even the 

 persistent vitality of Castilla in Soconusco. 



The planted trees at La Zacualpa abundantly demonstrate the prac- 

 ticability of rubber culture, but they leave the question of yield quite 

 in doubt, for during a period of several years the experiment was 

 abandoned, or at least entirely neglected, by the former owners of the 

 estate and the trees were left at the mercy of the local uleros, so that 

 it is now as impossible to learn how much rubber has been taken from 

 them as to know how large and how productive they would have been 

 had they been protected while young and tapped only with care and 

 moderation. 



It will be several years before adequate information on the }deld of 

 planted Castilla trees can be had, because, even after the trees have 

 reached a productive maturity of eight }^ears, an equal or longer 

 period may be needed for experiments with different methods and 

 times of tapping, before it will be known how the most rubber can be 

 taken out with the least injury to the trees. 



PROFITS AND PROSPECTS OF CASTILLA CULTURE. 



MANAGEMENT OF RUBBER PLANTATIONS. 



The extent and character of the correspondence received by the 

 Department of Agriculture during the last two years show that many 

 readers will expect rubber culture to be discussed not alone from the 

 standpoint of the planter, but from that of the investor as well. It 

 does not follow that any agricultural industry which may be profitable 

 for the individual planter will be equally advantageous for one who 



