Jan. i, 1925 Effect of Height of Chipping on Oleoresin Production 
87 
been clearly indicated. The fact that 
as much gum as usual, or even more, 
was obtained in this test from trees 
which had considerably less than half 
as large a scar as is frequently used is 
worthy of note. Not only is it a 
matter of scientific significance, the 
causes of which are to a considerable 
extent explained by studies of the 
microscopic structure of the wood, 
but it is a matter of practical im¬ 
portance as well. By lightening chip¬ 
ping an operator is at no additional 
expense; he is also, if this test is typi¬ 
cal, obtaining at least as high a yield 
as with the old methods. Further¬ 
more, he is keeping his trees more 
healthy and productive because reduc¬ 
ing the size of the wound, and, lastly, 
he is reducing the source of possible 
lumber degrading due to pitch-soaking 
behind the face. 
Additional data from this test and 
also results from “low” chipping 
experiments at other points will be 
available at the.end of the 1924 season. 
CALCULATION OF YIELDS ON A CROP 
BASIS 
The yield from the last 27 streaks, 
those cut according to test require¬ 
ments on the 20 selected trees in each 
group, converted to a yield per crop 
(10,000 cup) basis, is shown in Table 
III. In the test-yield figures the omis¬ 
sion of the amount of gum obtained 
from the first 6 streaks to some extent 
compensates for the fact that the crop 
calculation is based on the yield of 
selected trees.. Since the calculated 
figures may still be a little high, the 
possible excess has been further allowed 
for herein below by an arbitrary reduc¬ 
tion in the estimated value of the 
products. The difference in response 
of the three groups appears -to be a 
real one, as is shown in the microscopic 
data presented later. 
For comparison, the average results 
of working trees on a commercial 
operation were obtained for the tract 
in which the test trees stand. Here 
33,521 cups were included, in a first- 
year working by methods the same as 
those employed in test Group 2. The 
yield 9 obtained was 618.4 barrels of 
gum and 212 barrels of gum and 
scrape mixed. The latter produced 
about 8 gallons of spirits of turpentine 
per barrel and the former about 12. 
Hence the total, yield was approxi¬ 
mately 9,116.8 gallons, or 182.33 bar¬ 
rels, of turpentine. The number of 
cups worked was equivalent to about 
3.35 crops, so that the yield per crop 
(10,000 cups) averaged about 54.4 
barrels of spirits. By calculation of 
the Group 2 yields, without any de¬ 
duction, a production at the rate of 
about 60 barrels would be indicated. 
This, however, presupposes vigorous, 
healthy, comparatively young trees, 
which probably average higher in yield 
than many of the over-mature, old- 
growth trees which are of necessity 
included in the commercial working. 
Table III.— Conversion of test (20 cup) yield to a crop (10,000 cup) yield basis 
Chipping test on longleaf pine , Camp Pinchot , Fla., 1923 
Group l 
Group 2 
Group 3 
Yield from gum: 
1. Actual net yield of gum from 20 trees (Apr. 9 to Dec. 10,1923; first 
6 weeks omitted)_pounds. . 
2. Calculated net yield of gum for 10,000 cups__do- 
3. Calculated number of barrels of gum (net weight 410.5 pounds 
each)......barrels.. 
4. Calculated quantity of turpentine (one barrel of gum yields about 
12 gallons spirits)_____gallons.. 
5. Value at 98 cents per gallon----dollars.. 
6 . Number of barrels of turpentine (50 gallons each)-- barrels.. 
Yield from scrape: 
7. Actual net yield of scrape from 20 trees.___pounds.. 
8. Calculated net yield for 10,000 faces---do- 
9. Calculated number of barrels (net weight 310 pounds each) 
______barrels. . 
169.00 
84,500.00 
205.85 
2,470. 20 
2,420.80 
49.40 
43.00 
21,500.00 
69.35 
154.75 
77,375.00 
188.49 
2,261.88 
2,216.64 
45.24 
42.00 
2i;ooo.oo 
67.74 
151.00 
75,500.00 
183.92 
2,207.04 
2,162.90 
44.14 
51.00 
25,500.00 
82.26 
10. Calculated quantity of turpentine (one barrel yields about 5 
gallons spirits)____.gallons._ 
11. Vfiue at 98 cents per gallon-- dollars.. 
12. Quantity of turpentine (50 gallons per barrel)_barrels.. 
Calculated total yield, gum and scrape combined: 
13. Total quantity of turpentine per crop. (Selected trees, 27 streaks) 
(6+12)____barrels. . 
14. Quantity'Of turpentine from commercial operation (all trees, 32 
streaks)_baft-els.. 
15. Total value of spirits (5+11)--dollars. . 
16. Approximate total amount of rosin (No. barrels turpentine X 3) 
_ barrels.. 
17. Value of roan at $4.80 per barrel-1..dollars. _ 
,18. Total value of turpentine and rosin per crop (15+17)-do- 
346.75 
339.82 
6.94 
56. 34 
2, 760.62 
169.02 
811.30 
3, 571.92 
338.70 
331.93 
6. 77 
411.30 
403.07 
8.23 
52.01 | 52.37 
54.42 i_ 
2,548. 57 \ 2,565.97 
156.03 
748.94 
3, 297. 51 
157.11 
754.13 
3,320.10 
8 From information furnished through courtesy of the administration of the Florida National Forest. 
