BASIC COPPER SULFATE AS A FUNGICIDE 



143 



Table 12. Relative Effectiveness of Low and High Basic Sulfates and Lime-sulfur in 



Controlling Scab on Mcintosh and Red Astrachan Apples, and the 



Amount of Injury, — As Shown by the Yield 



Fungicide 



Row 



Lbs. 



Lbs. 



Mcintosh 



Low basic sulfate B 30 



High basic sulfate D 29 



Lime-sulfur F 30 



Check 



Red Astrachan 



Low basic sulfate A 30 



High basic sulfate C 28 



Lime-sulfur E 29 



Check 



228 7.60 



117 4.03 



119 3.97 



all fruit dropped 



700 23.33 



673 24.04 



1067 36.79 



all fruit dropped 



Evidently the fungicides were not the limiting factor with Mcintosh, but 

 may have had more influence with Red Astrachan. 



Doran and Bourne made fruit counts on 1851 Mcintosh apples from the several 

 plots on October 8, and obtained the following results : 



Table 13. Relative Effectiveness of Low and High Basic Sulfates and Lime-sulfur in 



Controlling Scab on Mcintosh, and Amount of Injury, — 



As Shown by Fruit Counts 



Fungicide 



Clean 



Per cent 

 Low basic sulfate 7.59 



High basic sulfate 23.90 



Lime-sulfur 62.65 



Check 



Scab 



Russet 



None of the fungicides gave proper control of scab on Mcintosh apples under 

 the conditions of operation, which indicates that the applications were improperly 

 timed. From the standpoint of clean fruit and a minimum of russet injury, 

 lime-suKur was superior to basic sulfates on Mcintosh that year. 



A dusting experiment was conducted on Block A of the Station orchard, under 

 the supervision of J. K. Shaw and W. A. Cutler, to determine the relative effective- 

 ness of low and high basic sulfates, copper-lime dust and lime-sulfur spray in con- 

 trolling scab on .5 varieties of apples, and the amount of injury to foliage and fruit. 

 The basic sulfates (lots 6 and 7) were mi.xed with le!ad arsenate and a free-flowing 

 talc and contained 3.00 per cent copper and 2.00 per cent arsenic. The copper- 

 lime dust was guaranteed to contain 3.94 per cent copper' and 2.92 per cent 

 arsenic. A standard mixture of lime-sulfur (33°B) and lead arsenate 1.25 gals.- 

 1.50-50 was employed for comparative purposes. The dusts were applied with a 

 Niagara power duster and the spray with a Friend power sprayer with 250-gallon 

 tank, under 275 pounds pressure, and Friend guns with 3/32 disc nozzles. The 

 trees on plots 1, 3 and 5 received nitrates while those on plots 2, 4 and 6 did not and 

 were less vigorous and had thinner foliage. In the pre-pink dust (May 7) which 

 was delayed nearly a week on account of the duster being out of order, and the 



'Actually tested 4.28'7 . 



