New York Agricultural Experiment Station. 327 



Trees.* 



Kind. No. 



Percent- 

 age oil. 



Besults. 



Atple: 



Principally Bald- 10 20 No injury, 

 win and Green- 

 ing. 



Principally Bald- 3 15 No injury, 

 win and Green- 

 ing. 



Principally Bald- 2 25 No injury, 

 win and Green- 

 ing. 



Principally Bald- 2 40 No injury, 

 win and Green- 

 ing. 



Principally Bald- 1 50 No injury, 

 win and Green- 

 ing. 



Principally Bald- 1 60 No injury, 

 win and Green- 

 ing. 



Principally Bald- 1 100 Slight burning of the foliage, 

 win and Green- 

 ing, 

 Pear: 



Dwarf Bartlett. 4 15 No injury. 



Dwarf Bartlett. 4 25 Very slight burning of foliage on wind- 

 ward side. 



{Nummary. — These experiments show, principally, the difference 

 between the 100° and 150° oils in their effects on apple and pear 

 trees. The former injured the foliage in all cases, even with 15 

 per ct., and when used at 60 per ct. and above seriously injured 

 the bark as well. The 150° oil did not injure the trees except 

 when used pure, when the foliage was slightly burned. 



general summary and discussion of results. 



The results taken as a whole indicate that peach and plum 

 trees are more susceptible to injury by kerosene oil than apple 

 and pear trees. Peach trees were the most sensitive, being 

 killed by the lowest percentage (20 per ct.) used. The experi- 

 ments to determine the percentage of high grade oil required to 

 kill the scales showed very definitely that a 20 per ct. mixture 

 had practically no effect, but that a 40 -per ct. mixture killed the 

 scales in every case. Kerosene oil of 100° fire test proved dan- 

 gerous to apple foliage at a percentage as low as 15, while ISO'' 



'Trees in full bearing. 



