﻿DRY SUBSTITUTES FOR UQUID LIME-SULPHUR 



11 



In the second generation the weaker strengths showed about 36.4 

 per cent and the greater strengths about 27 per cent, as many young 

 scales as were found on the untreated check. These figures show an 

 infestation 6.6 and 4.9 times as great as where the hquid hme-sulphur 

 was used. 



EXPERIMENTS IN 1923 



APPLE TREES 



The tests on apple trees were conducted at Stuart, Va., in an 

 18-year-old orchard moderately infested with scale. Plats of five 

 trees each were given a dormant spray on March 8, usihg a power 

 sprayer which maintained a pressure of 225 pounds with one spray 

 gun. An average of 12 gallons per tree was used. The composition 

 and dilutions o^ the essential materials in these sprays are shown 

 in Table 7. 



Table 7. — Composition of the dry calcium-sulphurs tested in experiments against 

 the San Jose scale in 1923 



Material used 



Percentage of— 









Quantity- 







used in 



Calcium 



Calcium 



.^ 



50 gallons 



poly- 

 sulphides 



thio- 

 sulphate 



sulphur 



of spray 









Pounds 



72.09 



9.45 



1.42 



15 



72.09 



9.45 



1.42 



27 



68.68 



11.18 



6.40 



15 



68.68 



11.18 



6.40 



27 



78.78 



9.00 



.86 



15 



78.78 



9.00 



.86 



26 

 Gallons 



30.34 



2.04 





6.66 





Pounds 

 of poly- 

 sulphide 

 in 50 

 gallons 

 of spray 



Dry lime-sulphur A .. 

 Do 



Dry lime-sulphur B ._ 

 Do 



Dry lime-sulphur C .. 

 Do _._. 



Liquid lime-sulphur i . 



10.81 

 19.46 

 10.30 

 18.64 

 11.81 

 20.48 



> Specific gravity 1.28, Baum§ 31.8°. 



The count of hibernating scales was made on April 11 and the first 

 generation of the scale on new wood was counted on June 27. The 

 results of these experiments are shown in Table 8. 



Table 8. 



-Results of tests against the San Jose scale made on apple trees at Stuart, 

 Va., in 1923 



Material used 



Dry lime-suIphur A.. 



Dry linnc-sulphur li . . 

 Dry liinc-su'jihur C. 



Liquid lime-sulphur.. 

 Check 



Quantity 

 in .50 



gallons 

 of spray 



Pounds 

 15 



27 



\r, 

 27 



I.', 



2/1 

 Oallont 



e.eo 



0) 



Hibernating scale 



Dead 



Per cent 

 48.7 

 69.1 

 d'J. 2 

 74.6 

 .-)0,0 

 71.4 



«7.0 



22. 7 



Control 



Per cent 

 33.6 

 60.0 

 47.2 

 67.1 

 3.5. 3 

 63.0 



Infestation of young scale on 

 80 linear inches new wood 



Total 

 scale 



289 

 124 

 294 

 117 

 258 

 132 



51 



Average 

 per inch 



3.61 

 1.55 

 3.08 

 1.46 

 3.23 

 1.65 



10.(1.'-, 



Percent- 

 age of 

 check 



35.9 

 15. 4 

 36.0 

 14.0 

 32. 1 

 10.4 



' Untreated. 



