272 
Journal of Agricultural Research 
Vol. XXXI, No. 3 
Table II .—Effect of girdling and 'poisoning treatments during period of growth , 
as observed at end of season 
Effect on tree 
Treatment 
Species 
Date 
treated 
Un¬ 
thrifty ° 
One- 
fourth 
dead b 
Dead 
GIRDLING 
Bark stripped off at base for distance of 24 to 40 
inches. 
Girdled with axe notch 1 to 2 inches deep. 
Barking and girdling combined_ 
Notch sawed and chipped 1 to 2 inches deep. 
Hemlock.. 
_do.. 
White fir_ 
_do_ 
Hemlock_ 
_do_ 
_do.. 
White fir_ 
....do.. 
_do_ 
.—do_ 
Hemlock. 
May 15 
June 15 
—do_ 
Aug. 15 
Sept. 15 
May 15 
June 15 
—do_ 
—do. 
Aug. 15 
...do_ 
June 15 
1 _ 
1 ... 
1 
1 
1 ... 
1 _ 
1 .. 
1 
1 ... 
1 
1 
1 
POISONING 
Notches 6 to 7 inches long filled with saturated 
solution copper sulphate. 
Four 3-inch auger holes filled with saturated 
solution copper sulphate. 
Notches filled with saturated solution copper 
acetate. 
Girdling notch and two auger holes filled with 
dry lye. 
No treatment control....— 
T tal. 
.do_ 
.do_ 
_do.... 
White fir_ 
May 15 1 
—do_ 1 
...do_ 1 
July 17 _ 
1 
Hemlock.. 
fHemlock. 
[White fir.. 
• Distinct yellow-green color of foliage. 
b One-fourth of inner leaves dead. 
e Almost dead or dead after Sept. 15. 
The damaging influence of the treatments at the end of the first 
season was, on the whole, negligible. Of 85 trees treated (omitting 
8 untreated control trees included in the series, and 7 trees blown 
down early in the season), only 16 showed any apparent effect what¬ 
ever. Of these, only 3 had died (1 hemlock and 2 white firs). The 
other 13 trees (8 hemlocks aiid 5 white firs) appeared to be distinctly 
more yellow-green in color than their untreated neighbors, and showed 
more than the ordinary number of dead leaves. Not much impor¬ 
tance can be attached, however, to this yellow-green appearance, as 
it may easily have been due to slight differences in exposure, soil, 
natural vigor of the tree, or other factors. The dying of inner leaves 
may havel 3 een just a natural shedding, as indicated by the fact that 
among the unthrifty trees was an untreated control tree. It is 
interesting to note, however, that the three trees which died were 
all girdled with a notch, two of them being axe notches and one a 
sawed notch. The percentage of the total basal area of the tree 
occupied by the notch ranged from 13.5 to 65.3, averaging 39.8 per 
cent for hemlock and 44 per cent for white fir. There seemed to be 
no relation;between the death of the three dead trees and this per¬ 
centage, the notches on the two white firs being below average and 
that on the hemlock somewhat above. 
Chemicals had been used in only four cases out of the 16. In two 
cases hemlock trees which showed a yellow-green cast to the foliage 
had been treated in open-chopped notches—in one instance with a 
