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BULLETIN 1311, U. S. DEPAETMENT OF AGEIGULTXJEE 



can not be considered satisfactory. Liquid lime-sulphur at 3.25 gal- 

 ions to 50 gallons of water was a little more effective than the weaker 

 strengths of the dry lime-sulphurs. 



These results are confirmed by the counts of young scales that 

 settled on the new wood, since the average number of scales found on 

 the tvvdgs treated with the weaker solutions of the three dry lime- 

 sulphurs was 25.9 times the number found in the liquid lime-sulphur 

 plat and approximately 50 per cent of the number found on the un- 

 treated check. The strongest solutions of the dry materials gave an 

 average of 59.7 per cent control and an average of 27 per cent as 

 many young scales on the new wood as were found on the untreated 

 checks. 



PEACH TREES, 1922 



The same spray materials (see Table 4) were tested against the San 

 Jose scale on peach trees at Canton, Miss., where plats of five trees 

 each were given a dormant spray on February 12 and 13. A barrel 

 pump, maintaining a pressure of 100 to 125 pounds with a rod and 

 disk nozzle, was used and an average of 1 3/2 gallons of spray material 

 was applied to each tree. 



The count of hibernating scales was made on March 7 and the 

 counts of the newly settled scales of the first and second generations 

 were made from June 1 to 3 and from August 10 to 12. The results 

 of these tests are given in Table 6. 



Table 6. — Results of tests against the San Jose scale on peach trees at Canton, Miss., 



in 1922 





Quantity 

 in 50 



gallons of 

 spray 



Hibernating 

 scale 



Infestation of young scales on 80 linear inches 

 new wood 



Material used 



Dead 



Control 



First generation 



Second generation 





Total 

 scale 



Average 

 per 

 inch 



Per 



cent 



of 



check 



Total 

 scale 



Average 

 per 

 inch 



Per 



cent 



of 



check 



Dry lime-sulphur A 



Dry lime-sulphur B 



Dry lime-sulphur C 



Liquid lime-sulphur 



Check. 



PmLnds 

 13.5 

 20 

 27 

 12.5 

 19.8 

 25 



13.5 

 20 

 27 

 Gallons 

 6.66 

 3.25 

 Untreated. 



Per ccntl Per cent 

 41.9 i 27.1 

 45. 4 31. 5 



54. 1 42. 4 

 43. 3 28. 9 

 49. 36. 



57.2 1 46.4 



39.1 1 23.7 

 48.6 i 35.6 



56. 2 45. 1 



77. 6 71. 9 

 31.2 i 13.8 

 20. 2 ' 



403 

 336 

 194 

 375 

 292 

 202 

 376 

 275 

 145 



37 



437 

 1,483 



5.04 

 4.20 

 2.42 

 4.69 

 3.65 

 2.53 

 4.70 

 3.44 

 1.81 



.46 

 6.46 

 18.54 



27.1 

 22.7 

 13.1 

 25.3 

 19.7 

 13.6 

 25.4 

 18.5 

 9.8 



2.5 

 29.5 



899 

 683 

 671 

 732 

 629 

 643 

 688 

 588 

 420 



117 



600 



2,121 



11.23 

 8.53 

 8.38 

 9.15 

 7.86 

 8.03 

 8.60 

 7.35 

 5.25 



1.46 

 7.50 

 26.51 



42.4 

 32.2 

 31.6 

 34.5 

 29.7 

 30.3 

 32.4 

 27.7 

 19.8 



6.5 

 28.3 











In the experiments reported in Table 6 the weaker solutions of 

 the dry lime-sulphur gave an average control of 26.6 per cent, and the 

 stronger solutions 44.6 per cent, as compared with a control of 71.9 

 per cent for liquid lime-sulphur. 



On the new wood the weaker strengths of the dry materials showed 

 an average of 4.8 scales of the first generation per linear inch. The 

 strongest solutions gave 2.25 per inch and the liquid lime-sulphur 0.46. 

 The untreated checks showed an average of 18.5 scales per inch. 



