184 MAINE AGRICULTURAL EXPERIMENT STATION. I915. 



Scab was first recorded on the foliage on the unsprayed check 

 plot on June 30, and abundant on both leaves and fruit on July 

 7. This condition prevailed throughout the season. 



Spray injury during the summer. Where bordeaux mixture 

 was used on plot i no spray injury was noted till July 7, or 

 something over 2 weeks after the third application had been 

 made. At this time russeting had begun to appear on the young 

 fruit, but there was no spotting of the leaves. However, foliage 

 injury developed quite rapidly during the next week, and by 

 July 14 many of the leaves were badly spotted and a few were 

 beginning to turn yellow and drop off. This defoliation in- 

 creased during the month and on the 5th of August it was 

 estimated that at least one-third of the leaves had fallen and 

 that the total number of injured ones represented at least 50 

 per cent. At harvest time nearly all evidence of early leaf injury 

 had disappeared. At this time while the foliage was noticeably 

 less dense, and some of the older leaves showed some spotting, 

 the general effect was such as to give the impression that the 

 foliage on this plot was more strong and vigorous and of a 

 richer green than on any other plot in the series. 



With regard to spray injury some very interesting observa- 

 tions were made on plot 2, sprayed with a 3-3-50 bordeaux 

 mixture when the blossom buds were showing pink and later 

 with arsenate of lead alone, at the rate of 2 pounds of the dry 

 powder to 50 gallons of water. The first evidence of any injury 

 was noted on the same date, July 7, that it was observed on the 

 adjoining plot sprayed 3 times with bordeaux mixture. At this 

 time the record shows "Doubtful russeting of the fruit." A 

 slight russeting was plainly evident on July 14, and this increased 

 somewhat during the remainder of the season. Slight leaf 

 injury was recorded on July 21, but this did not amount to 

 much -then or thereafter. The foliage was very vigorous and 

 healthy at harvest time. Attention is called to the fact that, as 

 is recorded below, no such injury was observed on plot 11 

 which was sprayed with double strength arsenate of lead for all 

 3 applications. Also, as is shown in the detailed record of the 

 condition of the fruit at harvest time, relatively few russeted 

 apples were produced on the last named plot. The possible 

 significance of these observations is considered later in the dis- 

 cussion of results. 



