6 EXPERIMENT STATION BULLETIN. 



orchard was used, but trees of any variety other than Stark and Bald- 

 win were not considered in the results. 



Materials. The orchard was divided into three plots with check 

 trees for each variety. They were arranged so that both Stark and 

 Baldwin were included in each plot. The arrangement of trees and 

 plots is show r n in Chart I. The different plots were treated as follows: 



Plot 1. Dusted. 90-10 mixture. 



Plot 2. Sprayed. Lime-sulphur, 1 to 40 and calcium arsenate (dry), 



1 Ib. in 50 gal. 

 Plot 3. Sprayed. Lime-sulphur, 1 to 40 and lead arsenate (paste), 



2i/ 2 Ibs. in 5.0 gal. 



Applications. The four regular application were made at the follow- 

 ing periods: 



1st. Pink or cluster application. 

 2nd. Calyx application. 

 3rd. Sixteen days after second. 

 4th. August 1st. 



RESULTS 



Foliage. On dusted trees the physical condition of the foliage was 

 very good. There was no injury that could be attributed to the dust- 

 ing materials. A small amount of scab developed on the foliage of the 

 Stark trees, but very little on Baldwin. 



On trees sprayed with lime-sulphur and lead arsenate there was very 

 little foliage injury. There was really not enough to consider so far 

 as the effect upon the trees was concerned. 



Trees sprayed with lime-sulphur and calcium arsenate showed much 

 more foliage injury than w r here lead arsenate was used. This was not 

 so severe as in some other orchards where this material was used. There 

 was practically no scab on the foliage of any of the sprayed trees. 



On the check trees, the physical condition of the foliage was very 

 good. On Baldwin foliage there was a little scab and on Stark foliage 

 it was quite noticeable. 



Fruit. With Baldwin there was so very little injury by disease or 

 insects that no accurate comparison can be made as to the value of the 

 different materials. Dusting gave slightly better control of insects, 

 other than coddling moth, than either lead or calcium arsenate applied 

 with water as the carrier. Of this type of injury there was 7.5% on the 

 check, 3.8% on both sprayed plots and 1% on the dusted plot. ,There 

 was no coddling moth injury where the trees were dusted or sprayed. 

 On the check tree there was only 3.8% injury. This is too low a per- 

 centage of wormy apples to be of any value as a check. 



With Stark, dusting and spraying -both gave satisfactory control of 

 scab. Dusting held injury by scab to less than 2%. In the lime-sulphur- 

 calcium arsenate plot, there was only 2.5% of scab injury. The lime- 

 sulphur-lead arsenate plot showed 5.4% of scabby fruit. This was prob- 

 ably due, in part at least, to part of the count trees being in lower 



