Jan i, 1925 Effect of Height of Chipping on Oleoresin Production 
91 
passages, particularly those formed in 
early spring, are comparatively short. 
By taking off high chips these are cut 
away before they have had an oppor¬ 
tunity to yield the gum which they 
are capable of producing. With such 
chipping, potentially valuable wood 
full of highly organized and productive 
tissue is cut off and thrown useless on 
the ground. In Plate 3 it is to be seen 
that no resin passages are present in 
the early springwood of the 1923 ring 
.of the specimens from the trees of 
Group 3. Here the early springwood 
had probably contained resin passages 
in June or July, but these, or at least 
some of them, were short and were 
probably entirely removed by the 
time the face reached its final height 
<21 inches). The cutting away of 
such resin passages is one of the marked 
wastes caused by high chipping. To 
be sure, there still remain many 
passages which are longer and will 
continue to produce gum, but a large 
percentage of available producing pow¬ 
er is thus needlessly wasted, despite 
the fact that conserving it as long as 
possible presents distinct advantages 
from every point of view. 
Observations have shown that in a 
given growth ring a considerable re¬ 
duction in tfie number of resin passages 
occurs from 1J4 to 3 feet above the 
early streaks of that year’s work. In 
one instance only half as many , resin 
passages were present in the face at 2 
feet above the first streak as were 
present at 1 foot up. The effect on 
wood formation of the wound of tur¬ 
pentining may, however, be much 
further extended vertically. Often the 
early virgin streaks affect the wood 
formed for 20 or more feet above, in 
respect to number of resin passages, 
width of ring, or amount of summer- 
wood. The greatest number of resin 
passages, however, have been found in 
a comparatively limited region of a few 
feet above the early streaks of a given 
year. 
Low chipping permits the operator 
to take advantage of this area for the 
longest possible time. The presence of 
the many resin passages in the .very 
early springwood of the specimen 
Group 1 trees represented in Plate 3 is 
an instance of available productive 
capacity which may be utilized. The 
faces on these trees were only 10 inches 
high. In such trees there is obviously 
a reserve of highly productive tissue 
present with which to start the second 
year of operation. These resin pas¬ 
sages will augment the yield until the 
freshly induced passages of the succeed¬ 
ing year develop and begin yielding at 
their maximum. 
Methods for building up one or more 
rings of such rich and productive wound 
tissue before starting regular turpen¬ 
tining are now being tested and present 
some very interesting possibilities. 
DISCUSSION or results: new 
WORK 
It is common knowledge among 
practical operators that all that is 
needed to freshen a streak on a turpen¬ 
tined pine sufficiently to secure a flow of 
gum is to remove the layer of wood 
forming the surface of the streak. The 
dimensions of the layer, however, vary 
widely in the practical application 
made by different woodsmen. 
After the cut surface of the streak 
has stood for a few days exposed to the 
air the wood cells tend to dry and to 
soak up gum, which they will not do 
when they are freshly cut and moist. 
It is then said that the streak has 
“lightwood” in it. Also, the gum 
which has flowed out from the resin 
passages dries and hardens to some 
extent on the streak surface, owing fo 
evaporation of the volatile spirits of 
turpentine. At and near the surface of 
the streak certain of the cells have been 
injured or killed by the chipping. It is 
obvious that these destroyed cells and 
the dried abnormal tissue must be re¬ 
moved. 
Undue drying frequently resultsfrom 
chipping too deeply. This practice 
tends to cause excessive soaking in of 
gum and the formation of a consider¬ 
able .amount of “lightwood.” If such 
a streak is chipped only inch high not 
all the “lightwood” may be removed. 
This result, however, does not neces¬ 
sarily prove that a higher chip should 
be cut. Rather it should suggest the 
possibility that perhaps the too deep 
chipping has caused interference with 
the circulation of the watery sap of the 
tree. It is obvious that enough sap- 
wood should be left behind the face to 
insure the moisture necessary to keep 
the living cells healthy and productive. 
Years of work on the Florida National 
Forest have shown that with J^-inch- 
deep chipping healthy, conditions are 
maintained even in trees in which the 
sapwood is not very wide. Studies of 
the effect of other depths of chipping 
are now under way at the Starke sta¬ 
tion and elsewhere. It is sufficient to 
say, at this time, that much of the 
criticism of low chipping, as, for instance, 
the statement that it “will not keep 
ahead of the lightwood, ” or will not re¬ 
move all the gum-soaked surface of the 
streak, and that it will radically reduce 
production, has resulted from obser¬ 
vation of trees which were already 
