42 



the Department, a series of extensive experiments was planned, for 

 the execution of which an orchard of 17,000 2-year-old peach trees was 

 secured from Mr. S. H. Rumph, at Marshallville, Ga. In addition a 

 near-by orchard of Mr. F. J. Frederick's, consisting of about 2.000 

 4-year-old peach trees was used, more particularly as a test of the 

 insecticides upon bloom buds. 



The larger orchard was divided into plots of 400 trees each, and 

 these were so arranged that each plot contained five or more varieties 

 of peaches. The orchard was badly infested with the San Jose scale, 

 less than 10 per cent of the trees being entirely free, and from 10 to 

 40 trees in each plot being either completely encrusted or nearly so. 

 The orchard became infested from local spread during the first season 

 after planting, and until the experiments were begun in November, 

 1901, it had received no treatment. 



In the Frederick orchard some scales were found on every tree, and 

 about 25 per cent of the trees were quite badly infested. 



The following substances were used in the experiments: 



Oils: 



Pennsylvania crude, 43° gravity. 



Refined kerosene, 150° flash test. 



Standard Oil Company's fuel oil. 



California distillate. 

 Soaps: 



Leggett's Anchor brand. 



Leggett's whale-oil soap compound. 



Good's No. 3. 



Good's No. 6, tobacco. 



Turpentine soap. 

 Caustic washes: 



Lime, sulphur, and salt wash. 



Crude potash. 



Resin wash. 



Carbolic acid emulsion. 



It should be explained that during the course of the winter a large 

 number of the scales perish without treatment. The females that have 

 reached maturity and commenced breeding rarely survive the winter. 

 In making up results, therefore, only the immature overwintering 

 individuals were counted. 



PETROLEUM OILS. 



Owing to delay in obtaining the crude oil no comparative tests were 

 made until January 15, when the work with oils was properly begun. 

 From that date applications were made at various intervals until 

 March 7, at which time the fruit buds were beginning to part their 

 petals. During the first week in December, however, kerosene in 

 soap emulsion was used at strengths of 10, 15, and 20 per cent. 



Nearly all sorts of weather conditions were met with, and an excel- 



