40 PROTECTION OF PLANTS, 1915-16 



(1) Lime sulphur (1-8, and iK pts. "Black Leaf 40" in 100 gallons 

 of the spray mixture). 



(2) Whale-oil soap 15 lbs., carbolic acid (commercial) 1 lb., and water 

 100 gals. 



Only 100 gallons of the first spray mixture were used on 20 trees, of 

 which 13 were thoroughly treated from both sides. An examination on May 

 19 showed practically complete control, only a few lice here and there being 

 found. The lice were so few and widely scattered that it did not seem feas- 

 ible to make counts. 



The second spray was used throughout the rest of the orchard. It 

 did not prove so effective though the number of lice were so few that no 

 damage was done to the fruit or foliage to warrant a second spraying. 



In order to determine whether a second spray applied at the time 

 the blossoms showed pink would aid in aphis control, Mr. Grossman applied 

 a spray of commercial lime-sulphur (1-40) and "Black Leaf 40," A pt. 

 in 100 gals, of the spray mixture. He used a single tank of 100 gallons 

 on a comparat'vely few trees and made a very thorough application. Al- 

 though a close examination was made on May 19, 1915, no better results 

 were apparent from the two treatments than from the single one applied as 

 the buds were showing green. Later examinations confirmed this con- 

 clusion. 



From these sprayings made under commercial conditions, Mr. Cross- 

 man is of the opinion that the lime-sulphur (1-8) with the addition of "Black 

 Leaf 40," 1 pint to 100 gallons of spray mixture, gave the best results when 

 applied as the buds were showing green. The whale oil soap combined with 

 the crude carbolic acid also gave excellent results but was not on the whole 

 so efficient though slightly less expensive. 



In order to determine whether the addition of carbolic acid is an active 

 agent in the destruction of plant lice several experiments were performed. 

 The following two experiments seem quite conclusive so far as I can deter- 

 mine : — 



(1). Carbolic acid (c.p.) 34 oz. 



Water 1 gal. 



This was applied carefully to two badly infested seedling trees on 

 July 7, 1914. On the 8th no effect on the lice could be observed except 

 that they were actively migrating. The tender terminal branch was prac- 



