﻿22 



BULLETIN 1371^ U. S, DEPARTMEI^T OF AGRICULTUEE 



Table 19 gives the chemical composition of the essential materials 

 in the dry barium-sulphur spraj^s used against the San Jose scale. 



Table 19. — The chemical composition of the dry barium-sulphur preparations tested 





Percentage of— 



Pounds 



used 



in 50 



gallons 



of spray 



Pounds 



of sul- 

 phides 



in 50 - 

 gallons 



Sample No. 



Barium- 

 sulphide 



Barium- 



thiosul- 

 phate 



Barium - 

 Free sulphate 



'^^P^^' i sofc'^eous 

 { material 



1 



41.22 

 41.22 

 41.22 

 38.00 

 38.00 

 38.00 



7.47 

 7.47 

 7.47 

 3.97 

 3.97 

 .^97 



31.05 

 31.05 

 31.05 

 34.01 

 34.01 

 34.01 

 33.66 

 33.66 



1 18. 32 

 1 18. 32 

 1 18. 32 

 24.43 

 24.43 

 24.43 

 25.14 

 25.14 



13 



19.5 



26 



13 



19.5 



26 



14 



31 



5.35- 



1 



8.03 



1 



10.71 



2 



4.94 



2.. . . 



7.41 



2 



9.88 



3 



39. 41 1. 28 

 39. 41 1. 28 



5.51 



3 



12.21 











' 1.94 per cent undetermined. 



EXPERIMENTS IN 192116 



Dry barium-sulphur No. 1 was tested against the San Jose scale 

 on apple trees at Washington, Ind. The results of these tests are 

 shown in Table 20. 



Table 20.^Results of tests with dry barium-sulphur sprays against the San Jose 

 scale on apple trees at Washington, Ind., in 1921 



Material used 



Quantity 



in 50 



gallons 



of spray 



Hibernating scale 



Dead 



Control 



Barium-sulphur No. 1.. . 



Pounds 

 13 



19.5 

 26 



Gallons 

 6.66 



Per cent 

 75.2 

 80.0 

 9L6 



88.4 

 71.0 



Per cent 

 14.5 



Do 



3L0 



Do 



7L0 



Liquid lime-sulphur ' 



60. 



Check 











1 Baum6 33.4°. 



The above experiments show that at the rate of 13 or 19.5 pounds 

 to 50 gallons of water this material did not furnish a satisfactory 

 control of the scale. When 26 pounds was used, it apparently gave 

 much better results than the liquid lime-sulphur, but, since such effec- 

 tiveness was not shown in any of the later experiments, it seems 

 probable that some other factor influenced these results. 



EXPERIMENTS IN 1922 " 



Dry barium-sulphur No. 2 was tested against the San Jose scale on 

 apple at Bicknell, Ind., and on peach at Canton, Miss. The results of 

 these tests are shown in Tables 21 and 22. 



16 For general conditions in these experiments see pp. 7-8. 



17 For details of these experiments see pp. 8-11. 



