38 BULLETIN 1064, U. S. DEPARTMENT OF AGRICULTURE. 



set of operating conditions may some day be found under which the 

 yields will not fall as markedly as is now usual. It has been held 

 that it is in the fourth year that the reduced response of the turpen- 

 tined trees is most marked. This also may be further delayed or 

 reduced by practicing better methods. 



REDUCING THE NUMBER OF CUPS TO THE ACRE. 



By applying the rules laid down for conservative chipping (p. 25) 

 the number of cups per acre would be materially reduced. Often a 

 50 per cent reduction would assure a higher yield. The argument 

 that the cup system has been bad for the trees, based on the fact that 

 the trees have been overcupped, may be true if one considers such 

 operations as one in which 232 cups were hung to the acre, but such 

 a procedure is unproductive and will not long be practiced by clear- 

 sighted operators. The fact that individual pines will survive under 

 excessively abusive treatment is no indication that high total yields 

 over a period of years may be obtained in this way. There is a case 

 on record, for instance, of a tree 9 inches in diameter 5 feet above the 

 the ground which had had two boxes cut in it that were operated for 

 five years. During the third year a cup was also added and the tree 

 continued to produce some gum, although it had all together only l-£ 

 inches of live bark between the faces. Again, a tree 6 inches in 

 diameter survived turpentining and grew fairly well. Such methods, 

 however, are to be deplored for the same reason that it was not desir- 

 able to kill the goose which laid the golden eggs. 



REPRODUCTION. 



Protecting the turpentined trees and the young growing seedlings 

 (PI. VII, fig. 7) from fire is of importance to the future of the indus- 

 try. Very important, also, is the protection of the seedlings from 

 destruction by hogs, which appear to prefer the roots of longleaf 

 pine to those of the less valuable loblolly pine. 



SUGGESTIONS FOR FUTURE RESEARCH. 



There are still many unsolved problems which are of importance 

 from the point of view both of commercial practice and of funda- 

 mental scientific knowledge. 



Of immediate significance is the question of the proper turpen- 

 tining of small timber. The existing second growth, the protected 

 natural reproduction, and the prospective plantations of slash and 

 longleaf pine will be the future source of naval stores. The results 

 presented here were obtained chiefly from large, mature timber. 

 The methods required for the successful turpentining of young trees 

 should have further study, especially with reference to the depth 



