44 



BULLETIN 229, U. S. DEPARTMENT OF AGRICULTURE. 



POSSIBILITIES OF WESTERN PINES AS A SOURCE OF NAVAL STORES. 



During 1911 and 1912 the Forest Service conducted experiments 

 on western yellow pine in Arizona, on western yellow pine, Jeffrey 

 pine, digger pine, singleleaf pinon, and lodgepole and sugar pine in 

 California and northeastern Oregon, and western yellow pine and 

 pinon pine in Colorado, to determine the quantity of crude gum 

 which could be secured from these pines by the methods ordinarily 

 employed in the turpentining of longleaf yellow pine in the South- 

 east. 1 The field work was supplemented by laboratory analyses to 

 determine the quality of the gum. 



Table 18 compares the yields obtained in Arizona with those ob- 

 tained in experiments conducted on a commercial scale in Florida. 

 The Arizona experiments show a yield from western yellow pine 

 about four-fifths as great as that obtained from southern yellow pines 

 on average operations in Florida in the same period of time. Weather 

 conditions in Arizona, however, will allow only a 24, or possibly a 

 26-week season, as against 30 or 35 weeks in the Southeast, so that 

 when the yields for the entire season are compared western yellow 

 pine shows a production about two-thirds as great as that from 

 southern yellow pine. The average proportions of rosin and turpen- 

 tine in the gum were about the same in both regions, as was the 

 composition of the turpentine. 



TABLE 18. Comparison of yields, in pounds, of crude gum and scrape from western 

 yellow pine in Arizona and longleaf pine in Florida. 



1 Each crop of 500 cups chipped 24 times. 2 Each crop of 8,000 cups chipped 31 times. 



The California experiments on western yellow pine were carried 

 on from July 7 to November 1, 1911, and from May 10 to August 3, 

 1912. The yields obtained in 1911 and 1912 are combined in Table 

 19, to show the flow for an entire but not a continuous season. 



1 The California and Oregon experiments were made under the direction of Mr. C. Stowell Smith and 

 Mr. J. B. Knapp, assistant district foresters, districts 5 and 6. A complete report of this work is on file 

 at the Forest Service, Washington, D. C., and at the Forest Products Laboratory, Madison, Wis. For a 

 detailed description of the Arizona and Colorado experiments see Forest Service Bulletin 116, "Possibilities 

 of Western Pines As a Source of Naval Stores," by H. S. Betts. 



