MICHIGAN ACADEMY OF SCIENCE. 113 



Plot 2. 



Sprayed some time after the rains in Jiilv and .j days before the 

 lieavy rain of Anjinst 18, wlien most of the infection took place. 



August S Scab appeared. 

 August 15 15% on sprayed side. 



40% on unsprayed side. 

 August 10 25% on sprayed side. 



40% on uuspraj^ed side. 



The entire lot was abandoned the next week from scab. 

 Plot 3. 



This i»lot was sprayed from uim to three days after every i-aiiK 

 and in no case were vines freshly covered with spray previous tc 

 heavy storms. 



August 17. Scab appeared. 

 August 27 50% on sprayed side. 



70% on unsprayed side. 



An infection of 50% does not rei)resent control as this is equiva- 

 lent to almost total loss of the crop. 



Plot J,. 



Sprayed one to two days previous to all rains in August, never 

 more than two days previous to any rain. 



August 7 Scab appeared. 

 August 27 10% on sprayed side. 



70% on unsprayed side. 

 September 3 No change on sprayed side. 



This plot shows very fair results in control of the fungus. 



Plot 5. 



Sprayed no more than three days jn'evious to all rains in August 

 and only a few hours before that of August ISth. 



August 19 Scab appeared. 



August 2(3 5% on the sprayed side. 



15% on the unsprayed side. 

 August 30 100% on the sprayed side. 



40% on the unsprayed side. 



This shows partial control of the disease, although the unsprayed 

 side is rather badly infected. 

 15 



