ANNUAL REPORT, 1930 255 



sulfur combination used witii and without tiie addition of a casein spreader. 

 The schedule which was followed consisted of a pre-blossoin and a calyx 

 spray, two cover sprays, and an apple maggot spray in July. 



The aluminum sulfate— calcium arsenate— lime-sulfur combination showed 

 excellent persistence and caused neither injury to foliage nor russeting of 

 fruit. 



Calcium arsenate and lime-sulfur showed good adhesive qualities but 

 caused considerable burn to foliage of Mcintosh and serious burn on other 

 varieties. With the addition of excess lime burn was not so severe but 

 was present on all varieties including Mcintosh. Both sprays caused ,i 

 considerable drop of leaves during June and July, although to a less de- 

 gree when excess lime was added. 



Slight burn was noted following the lead arsenate — lime-sulfur combina- 

 tion both with and without casein spreader. The varieties showed con- 

 siderable difference in susceptibilitv to burn. Injury was most pronounced 

 on foliage of Baldwin and King; least so on Mcintosh. 



Flotation svdfur and calcium sulfide, two new materials designed to re- 

 place lime-sulfur as fungicides, were used in combination with lead ar- 

 senate to test their compatability with that material. These were used 

 in lilocks of Mcintosh, a variety subject to scab, and Baldwin, which is 

 very susceptible to spray burn and russeting. Neither of these materials 

 caused injury to foliage or russeting of fruit on either variety, and both 

 showed good coverage and excellent persistence throughout the season. 



The comparative value of these sprays is shown in the following table, 

 based on examination of tlie Mcintosh crop at harvest. 



Mcintosh Apples, Block A 



PERCEXTAGE OF FRUIT SHOWING 



Treatment Scab Insect Injury 



Calcium arsenate 1 



Aluminum sulfate > 37 



Lime-svdfur J 



Calcium arsenate ) ^ „. 



Lime-sulfur 3 



Calcium arsenate ^ 



Lime-sulfur > 2 28 



Excess lime J 



Lead arsenate | ^ „_ 



Lime-sulfur - j 



Lead arsenate ] 



Lime-sulfur -j- 2 14 



Spreader J 



Check : 54 58 



Mcintosh Apj>les, Block E 



Flotation sulfur | ^ .-, . 



Lead arsenate | ~ 



Calcium sulfide - ^ ■ a 



Lead arsenate — j 



Lead arsenate ) • . -^ 



Lime-sulfur j 



Check 55 49 



