104 Maine Agricultural. Experiment Station. 1918. 



rain fell on the 18th, and the 19th also was cloudy. Between 

 May 20 and June 5, the date of the second application, there 

 were 7 wholly fair days. Rain fell on 5 different days but this 

 was slight, except on May 30 when .95 of an inch was recorded. 



At the time of the second application the petals had not 

 entirely fallen but weather conditions indicated that it was un- 

 safe to delay farther. On this date, June 5, the forenoon was 

 clear but the afternoon was cloudy. Late in the afternoon .05 

 of an inch of rain fell but this occurred after the plots had been 

 sprayed and the material applied had become dry. 



Of the 17 days that intervened between the second and 

 third applications only 3 were recorded as entirely fair. Rain 

 fell on 9 of these days. The total rainfall for June was 4.20 

 inches, making the combined total for May and June nearly 10 

 inches. It would seem that the weather conditions just prior 

 to the first application of the sprays and from then on till the 

 third application had been made were extremely favorable for 

 scab infection and development. As will be shown later nearly 

 39 per cent of the fruit on the unsprayed plot was scabby. Un- 

 doubtedly this would have been greatly increased were it not 

 for the fact that the experimental plots were all plowed prior 

 to May 8, thus turning under the diseased leaves of the season 

 before, except those near the bases of the trees, previous to the 

 complete development of the ascospores of the scab fungus 

 upon the leaves, under local climatic conditions. 



Effect of the Different Sprays on the Foliage and Fruit 

 During the Summer of 1916. 



Plot 1. Standard dilution lime-sulphur and acid arsenate of 

 lead. 

 A very slight amount of injury to the tips of the leaves 

 was noted on June 22. By the middle of July some burning 

 of the margins was apparent but this was not bad. Russeting 

 of the fruit was quite evident at this time and was plainly 

 greater than on the unsprayed check. These effects did not 

 materially increase during the remainder of the season. After 

 the middle of July a small amount of scab was noted on the 

 leaves but none on the fruit before harvesting. 



