﻿8 BULLETIN 13'71_, U. S. DEPARTMENT OF AGEICITLTURE 



Table 2. — Composition of the dry calcium-sulphurs tested in experiments against 

 the San Jose scale in 1921 



Material used 



Per cent of— 



Calcium 



polysul- 



Dhide 



Calcium 

 thiosul- 

 phate 



Free sul- 

 phur 



Quantity 

 used in 

 50 gal- 

 lons of 

 spray 



Quantity 

 of poly- 

 sulphides 

 in 50 gal- 

 lons 



Dry lime-sulphur A ! 71.87 ! 7.38 



Do : 71.87 ] 7.38 



Do j 71.87 7.38 



Dry lime-sulphur B J 64.80 8.81 



Do 64.80 I 8.81 



Do — I 64.80 I 8.81 



Dry lime-sulphur G 73.92 1 9.35 



Do ' 73.92 i 9.35 



Do_- - 73.92 I 9.35 



Liquid lime-sulphur ' 31.57! 1.95 



Do 31.57 i 1.95 



4.70 

 4.70 

 4.70 

 11.15 

 11.15 

 11.15 

 4.09 

 4.09 

 4.09 



13.5 lbs. 

 20 lbs. 

 27 lbs. 

 12.5 lbs. 

 19.5 lbs. 

 25 lbs. 

 13.5 lbs. 

 19 lbs. 

 27 lbs. 

 6.66 gals. 

 3.25 gals. 



Pounds 

 9.70 

 14.37 

 19.40 

 8.10 

 12.63 

 16.20 

 9.97 

 14.04 

 19.95 

 22.75 

 11.10 



1 Sp. gr. 1.30; Baumg 33.4°. 



On April 23, twigs were taken from all parts of the trees and a 

 count of 1,000 hibernating scales was made for each plat. The 

 results of these experiments are given in Table 3. 



Table 3. — Results of tests against the San Jose scale made on apple trees at 



Washington, Ind., in 1921 



Material used 



Quantity 



in 50 gal 



Ions of 



spray 



Hibernating scale 



Dead Control 



Dry lime-sulphur A. 

 Dry lime-sulphur B . 

 Dry lime-sulphur C. 



Liquid lime-sulphur 

 Check... 



Pounds 

 13.6 

 20 

 27 

 12.5 

 19.5 

 25 

 13.0 

 19 

 27 



Gallons 

 6.66 

 3.25 

 (1) 



Per cent 

 75.2 

 83.6 

 80.4 

 78.3 

 84.0 

 83.1 

 7L2 

 89.6 

 84.0 



88.4 

 70.4 

 7L0 



Per cent 

 14.5 

 43.5 

 32.4 

 25.2 

 44.8 

 41.7 

 .7 

 64.1 

 44.8 



60.0 

 



1 Untreated. 



The results shown in Table 3 indicate that at dilutions of 12.5 to 

 13.5 pounds to 50 gallons these dry lime-sulphurs were of no' practical 

 value against the San Jose scale, and when the strength was increased 

 they did not furnish a practical control. Liquid lime-sulphur used at 

 the rate of 3.25 gallons to 50 gallons of water, which is rouglily equiva- 

 lent to the weaker strength of the dry materials, was of no value. 



EXPERIMENTS IN 1922 



The experiments on apple trees in 1922 were conducted at Bicknell, 

 Ind., in a scale-incrusted orchard, which was divided into plats of 

 three to five record trees. The application was made on March 15, 

 using a power sprayer which maintained a pressure of 250 to 275 

 pounds with one spray gun and one rod. From 9 to 10 gallons of 



