Naval Stores: The Forests 



293 



than from the larger, old-growth trees. 



During the decades in which pro- 

 duction per tree, per acre, and per 

 man were declining in the turpentine 

 woods, efficiency in the use of labor 

 and introduction of mechanical devices 

 were advancing steadily in the indus- 

 tries that compete with naval stores for 

 markets and manpower. Those indus- 

 tries captured more and more of the 

 gum naval stores market. Gum naval 

 stores producers were unable to keep 

 enough workers in the woods to meet 

 production goals during the war and 

 the industry may continue to lose 

 ground in the postwar competition 

 unless improvements in technique and 

 equipment are successful in raising the 

 efficiency of production. Since most of 

 the labor is expended in producing raw 

 gum in the woods and little is needed in 

 processing it, more efficient methods of 

 gum extraction and harvesting are 

 obviously needed. For example, it is 

 necessary in the traditional methods of 

 turpentining to visit each tree 40 times 

 a season to produce a yield of 8 or 9 

 pounds of crude gum or oleoresin. 



Recent research has centered on sev- 

 eral improvements that give promise 

 of correcting as rapidly as possible the 

 inefficiency of gum harvesting. 



APPLICATION OF ACID to the streak 

 to stimulate the flow of gum is the most 

 promising new technique that has been 

 developed since the introduction of the 

 cup several decades ago. Experiments 

 at the Lake City Branch of the South- 

 eastern Forest Experiment Station 

 have demonstrated that streaks sprayed 

 with sulfuric acid yield 50 to 100 per- 

 cent more gum than untreated streaks. 



Treatment with sulfuric acid also ex- 

 tends the normal period of gum flow 

 after chipping. As a result, the streaks 

 chipped every 2 weeks and sprayed 

 with acid produce as much gum per 

 season as untreated streaks applied at 

 the usual weekly interval. Although the 

 additional work of spraying acid slows 

 down the chipper to about 90 percent 

 of his usual speed, the longer chipping 

 interval permits him to work up to 80 



percent more timber with no sacrifice 

 in yield per tree. In that way a chipper 

 can increase his production for the 

 season by 80 percent. If the interval of 

 chipping and acid treatment is in- 

 creased to 3 weeks, the yield per tree is 

 somewhat less, but the greater number 

 of trees that are worked under this sys- 

 tem enables a chipper approximately to 

 double his output of gum for the year. 

 Chemical stimulation may also help 

 to save a portion of the butt log for 

 timber production. Doubling the cus- 

 tomary chipping interval and applying 

 acid provides approximately normal 

 annual gum yields while proceeding 

 only a little more than one-half as high 

 up the tree. Or, in trees designated for 

 thinning or harvest cutting, the usual 

 total yield for the normal 5- or 6-year 

 life of a face can be obtained in a 

 shorter period of years by chipping at 

 the customary interval but applying 

 acid in addition. Although sulfuric acid 

 has a greater effect on prolongation of 

 gum flow than any chemical that has 

 yet been tried, it is corrosive and must 

 be handled with caution. Research men 

 are bending every effort to find a gum- 

 flow stimulant that will be nearly as 

 easy to handle as water. 



A NEW SYSTEM OF CHIPPING involves 



cutting to the usual height of one-half 

 inch but only to the depth of the outer 

 surface of the wood. If acid is applied, 

 the method gives just as much gum as 

 does application of acid with the tra- 

 ditional method of chipping one-half 

 inch into the wood. The new technique 

 of "bark chipping" is now in its fifth 

 year of use by selected cooperators in 

 the industry. It requires less physical 

 effort than the standard method, is 

 easier to teach to new workers, and 

 leaves the butt of the tree in better con- 

 dition for utilization. The spread of 

 this new method depends on the ac- 

 ceptance of chemical stimulation, for, 

 without application of acid, the yield 

 is less than for the traditional chipping. 

 A new type of tool, or hack, has been 

 developed for bark chipping. This new 

 method of taking off only the bark pro- 



