EXPERIMENTAL SPRAYING AT HIGHMOOR FARM. 87. 



Practically no scab developed even on the check plots the first 

 year but during the last 3 years there was an average increase 

 of 8 per cent of merchantable apples as the result of using the 

 stronger spray. The greatest increase in any one year was 21 

 per cent in 191 2. That season, however, through a misunder- 

 standing in the writer's absence, the first spray application on 

 both plots was omitted. While the conditions of the test were 

 equally severe in both cases it is possible that if the applications 

 had been made when the fruit buds were showing pink the dif- 

 ferences between the two plots would not have been so great. 

 As will be shown later this first application was a very impor- 

 tant one that season. 



Only one reason -was increased foliage injury noted where 

 the stronger spray was used and this was slight. Contrary to 

 expectation there was, two years out of 3, more russeting oi 

 the fruit where the weaker spray was used. These difference?, 

 however, averaged less than 3 per cent. 



From the work of the 3 seasons it would seem that on the 

 Ben Davis, a variety easily injured by bordeaux mixture, a 

 dilution of lime-sulphur at least 20 per cent stronger than the 

 commonly recommended may be used with comparative safety. 

 Also in some seasons, at least, the greater efficiency in scab con- 

 trol secured will more than cover the added cost of materials. 



The importance of the blossom bud application: Certain stu- 

 dents of the subject of apple scab control have laid much 

 stress upon the importance of the spray application made when 

 the fruit buds are showing pink. Present knowledge of the life 

 history of the apple scab fungus and some experimental data 

 obtained in Maine tend to confirm these conclusions derived 

 from work done elsewhere. However the results secured at 

 Highmoor during 4 consecutive seasons indicate that under 

 Maine conditions it is not necessarily a foregone conclusion 

 that the spraying operations for the current year are doomed 

 to utter failure if no spray is applied till after the petals fall. 



Two seasons out of the 4, omitting the blossom bud applica- 

 tion of lime-sulphur entirely actually resulted in a higher per- 

 centage of merchantable apples. Another season the increased 

 efficiency due to the first application was of little account. The 

 differences for all 3 seasons were slight, however, and were 

 doubtless within the limits of experimental error. Therefore 



