LONGLEAF PIXE. 
23 
working of second-growth, well-stocked longleaf pine stands. 
Caution is necessary, however, in using the table, since it should be 
regarded as based upon insufficient data to make it final, but it is 
probably the best of its kind available. It is not based upon actual 
yields from whole stands, but has been computed from two sets 
of independent measurements, one relating to the sizes and numbers 
of trees pei-aere of growing longleaf stands (Table 1), and the 
other relating to the flow of gum from a limited number of trees 
of specified sizes (see Table 12). On the basis of this information, 
secured by the Forest Service. U. S. Department of Agriculture, 
the table was compiled jointly by the State Department of Con- 
servation, Xew Orleans, La., and the Forest Service. It is included 
here with the hope that it may be the means of stimulating the 
collection of further measurements and the acquisition of more com- 
plete information. The yield of gum per crop is exceedingly vari- 
able, as is well known among operators, depending upon the locality 
and region (extending from North Carolina to Texas), the season, 
class of labor, and indirectly the market conditions. Hence, any 
figures of yield should be used with discretion. 
Table 11. — Computed production of gum, turpentine, and rosin from veil- 
stocked second-groutlx longleaf pine stands, of various ages {virgin, or first 
year's working). 1 
Production per crop. 
! Age of 
stand. 
Gum. 
Years 
20 
30 
40 
50 
Pounds. 
37.000 
53,000 
08.000 
74,000 
Turpen- 
tine. 2 
Barrels 
(50 gals.). 
18.5 
26.5 
34.0 
37.0 
Rosin. 2 
Barrels 
(500 lbs.). 
61 
88 
113 
123 
Produc- 
tion 
of gum 
per cup. 
Production per acre. 
Gum. 
Pounds. Pounds. 
5.3 
6.8 
7.4 
1,122 
2.190 
2.760 
Turpen- 
tine. 2 
Gallons. 
4.6 
28.0 
54.7 
69.0 
Rosin. 
Barrels 
(500 lbs.). 
0.3 
1.9 
3.7 
4.6 
Trees 
per 
acre in 
stand 
(all 
sizes). 
Trees cupped per acre (grouped by diameter sizes). 3 
Cups 
per 
acre. 
Diameter of trees — inches. 
Total. 
7 S 9 
10 11 
12 
13 
4.50 
355 
308 
280 
50 
50 
210 
241 
250 
50 
210 
321 
371 
70 : 90 i .50 
38 43 .50 
33 38 40 
* 5 45 
* 65 56 
25 
15 
1 This table is computed from two different sets of measurements and is not based upon actual measured 
yields of whole stands. The working of small trees and young stands is not good practice except where 
trees are to be removed in thinnings or the land to be cleared for other uses. 
* Production of turpentine and rosin calculated on the basis of KM) pounds of gum yielding 2}- gallons 
of turpentine (one-twentieth barrel) and S3 pounds ofrosin (one-sixth of a 500-pound barrel). 
3 One cup hung on each tree measuring 7 to 9 inches, inclusive, in diameter; two cups hung on about 
one-half of the 10-inch trees and on all trees measuring 11 inches and over. 
« In the 40-year-old stand, 35 of the total 65 trees were 2-cup trees: in the 50-year-old stand. 25 of the 45 
trees; and in both cases the remainder of the 10-inch class of trees were hung with one cup each. 
