Apple Spraying Experiments in 1916 and 1917. 105 



Plot 2. Same as plot i, using Friend calyx nozzle. 



The record for this plot throughout the season was identi- 

 cal with that for plot I. 

 Plot 3. Standard dilution lime-sulphur and arsenate of lime. 



The amount of scab and leaf injury was also essentially the 

 same on plot 3 as on plot 1, except that after the first of August 

 the amount of foliage injury on 3 where arsenate of lime had 

 been used with lime-sulphur was considerably more common. 

 This observation was carefully checked since it was unexpected. 

 On the other hand, fruit russeting was less apparent on plot 3 

 than on plot 1. 



Plot 4. Standard dilution lime-sulphur and acid arsenate of 

 lead, first application omitted. 



On plot 4, scab on the foliage was as well controlled as on 

 plot 1 where all 3 applications of lime-sulphur and arsenate of 

 lead were made. In comparison with plot 1, plot 4 in the early 

 part of the season showed somewhat less leaf injury. 

 Plot 5. First application stronger lime-sulphur and acid ar- 

 senate of lead ; last two, double strength acid arsenate 

 of lead alone. 



No leaf injury was recorded. The general condition of the 

 foliage was better than on plot 1 throughout the season, although 

 a slight amount of scab was noted at about the same time that it 

 was observed on the latter. 

 Plot 6. Acid arsenate of lead alone, double strength. 



Scab appeared on the leaves at the same time as on plots 

 1 and 5 and was evidently somewhat more common. A careful 

 comparison of plot 6 with plot 9, the unsprayed check, showed 

 that on July 18 the number of scabby leaves and fruit were 

 much greater on the latter. It was estimated at that time that 

 the use of arsenate of lead alone as a spray had reduced the 

 amount of scab on the foliage from 90 to 95 per cent. 

 Plot 7. Bordeaux mixture, 3-3-50, and acid arsenate of lead. 



With bordeaux mixture, as in the past, a large amount of 

 leaf injury and defoliation appeared early in the season and 

 much leaf spotting was apparent even up to harvest time. No 

 scab was observed on this plot previous to harvesting. 

 Plot 8. Sherwin-Williams Co. dry lime-sulphur and acid ar- 

 senate of lead. 



