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BULLETIN 1371, U. S. DEPARTMENT OF AGBICULTUEE 



EXPERIMENTS IN 1921 12 



In these tests dry sodium-sulphur No. 1 was used against the San 

 Jose scale on apple trees at Washington, Ind. The results of these 

 tests are shown in Table 13. 



Table 13. — Results of tests with dry sodium-sulphur sprays against the San Jose 

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



Material used 



Amount 



in 50 

 gallons of 



spray 



Hibernating scale 



Dead 



Control 



Sodium-sulphur No. 1 



Pounds 

 12.5 

 19 

 25 



Gallons 

 6.66 



Per cent 

 79.0 

 83.8 

 84.4 



88.4 

 71.0 



Per cent 

 27. a 



Do . 



44.1 



Do 



46.2 



Liquid lime-sulphur ' 



60.0 



Check .... 











» Baume 33.4°. 



The tests recorded in Table 13 show clearly that, even when a large 

 percentage of the scales die from natural causes, dry sodium sulphur 

 does not serve as an effective remedy. They also show that when 

 the conditions are such that the standard liquid lime-sulphur treat- 

 ment falls below what can be considered an effective control this 

 preparation is even less effective. Although increasing the dosage 

 increased the efficiency of the dry sodium-sulphur, in no case was an 

 effective control obtained. 



EXPERIMENTS IN 1922 » 



Dry sodium-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 given in Tables 14 and 15. 



Table 14. — Results of tests with dry sodium-sulphur sprays against the San Jose 

 scale on apple trees at Bicknell, Ind., in 1922 



Material used 



Quantity 



in 50 



gallons 



of spray 



Hibernating scale 



Infestation of young scale on 

 80 linear inches of new 

 wood 



Dead 



Control 



Number 

 of scales 



Average 

 per inch 



Percent- 

 age of 

 check 



Sodium-sulphur No. 2. 



Pounds 



12.5 



19 



25 

 Gallons 



6.66 



Per cent 

 63.4 

 73.7 

 85.4 



97.6 

 55 



Per cent 

 18.7 

 41.6 

 67.6 



94.7 



4,086 

 2,528 

 1,140 



175 

 8,873 



51.1 

 31.6 

 14.3 



2.19 

 no. 91 



46.0 



Do. 



28.5 



Do 



12.8 



Liquid lime-sulphur ' 



2.0 



Cheek 













1 Baumg 32.6°. 



Table 14 gives the results of tests in an orchard where the scale was 

 increasing very rapidly. Under these adverse conditions liquid lime- 

 sulphur gave a very good control but the dry sodium-sulphur spray 



" For details of these tests see p. 7-8. 



» For details of these tests see pages 8-11. 



