26 



BULLETIN 229, U. S. DEPARTMENT OF AGRICULTURE. 



The immediate danger of destruction of the timber is not so great 

 while the trees are being turpentined as when the crop has been 

 abandoned, since during the period of active operation the trash is 

 raked from about the trees. Few tracts of timber escape the annual 

 burning over, and turpentined trees are often either killed directly or 

 permanently injured. While the damage to abandoned cupped 

 timber is heavy, it is not so serious as in boxed timber, since the cups 

 are removed when the trees are abandoned and the faces are the 

 only source of fire risk. 



INJURY TO GROWTH. 



The box enters the tree so deeply as to injure its vitality and 

 retard the process of growth. Boxes are generally cut in the most 

 prominent root swellings, especially in leaning trees, as when so 

 placed they will more readily catch the gum and are also easier to 

 cut. The box undoubtedly curtails the food supply of the tree to a 

 considerable extent and accounts for the fact that more "boxed" 

 than "cupped" trees die after tapping. 



The box weakens the tree so that it is liable to be blown down by 

 the first storm. This is especially true of small timber which may 

 have from one-half to two-thirds of its diameter severed by the box, 

 and of timber in old orchards that has been "back-boxed," i. e., 

 boxes cut between the old ones wherever there is available space. 



The following tabulation compares the number of dead and blown- 

 down trees in half crops worked with cups and boxes for one season : 



Trees blown down. 



Trees dead. 



Boxed. 



Cupped. 



Boxed. 



Cupped. 



5 

 8 



1 

 3 



2 

 35 



1 

 16 



After 16 chippings. 

 After 32 chippings . 



Since the box fills with water after the trees are abandoned, the 

 surrounding wood is kept moist, increasing the likelihood of attack 

 by fungi and subsequent decay. In some cases the box is filled with 

 earth after abandonment to prevent it from catching fire. While it 

 may serve the latter purpose, the procedure is scarcely to be recom- 

 mended, since the earth retards evaporation of the water and hastens 

 decay. 



Trees that have been "boxed" are sometimes attacked by bark- 

 boring and wood-boring insects, the former killing the trees and the 

 latter seriously damaging the wood. 1 



QUALITY OF LUMBER IN "TURPENTINED" AND "ROUND" TIMBER. 



The wood back of the "faces" in timber that has been turpentined 

 for several years is generally impregnated with resin for a depth of 

 from one-half to one and one-half inches. As very resinous material 



See U. S. Department of Agriculture Farmers' Bulletin 476, and Yearbook 1909, pp. 410-412. 



