20 Direcror’s Report orf THE 
Taken as a whole these experiments indicate the following: 
1. Vigorous trees are probably less liable to injury by crude 
petroleum than weak ones. 
2. Peach and plum trees are more sensitive to crude petro- 
leum than apples, cherries or pears. 
3. There is less danger of injury if trees are sprayed in early 
spring than during the fall or winter. 
4, The 25 per ct. emulsion of crude petroleum and water can- 
not be depended upon to kill the hibernating scales in the 
latitude of western New York while the 40 per ct. has proven 
efficient. 
5. Much pains should be taken to avoid over-drenching the 
trees. Only enough of the emulsion should be applied to wet 
_ the bark evenly and thoroughly. 
Washes.—The resin-lime mixture and government whitewash 
did not adhere to the trees well and apparently had but little 
effect on the scales. 
Funigation—The fumigation experiments in western New 
York with hydrocyanic acid gas were also divided into two 
series. Series I included the experiments to determine the 
effect of the gas upon bud sticks for budding purposes, and 
Series II the strength of the gas required to kill the hibernating 
scales. In both series the gas was used at strengths varying 
from .18 to .3 gram of cyanide of potassium per cubic foot of 
air space. The exposure of the buds to the gas varied from one- 
half hour to one hour. 
The experiments with buds, while not entirely satisfactory 
owing to the somewhat unfavorable conditions surrounding the 
treated buds, gave sufficiently uniform results to indicate clearly 
that the gas is harmless except in the case of the peaches, which 
were evidently injured slightly by the gas at .8 gram of cyanide. 
There was but little difference in the percentage of treated buds 
that set and the checks. -In all 4,488 buds were treated, 78 per 
et. of which set. The checks numbered 4,864, of which 85.5 per 
ct. set, making but a slight difference in their favor. This differ- 
