through June, July, and August; 2) the 'New York' 

 program of waiting until 150 hours of wetness had 

 accumulated since the most recent fungicide appli- 

 cation; and 3) the 'North Carolina' model of wait- 

 ing until 200-250 hours of wetness had accumu- 

 lated after the primary infection period for these 

 diseases. 



A modified hygrothermograph unit was used 

 to measure the wetting periods in both orchards. 

 The weather units were set out prior to blossom. 

 The time of petal fall was noted (May 10 at 

 Clarkdale Orchards; May 1 1 at Alyson's Apple 

 Orchard) and wetness-hours were accumulated 

 beginning 10 days after petal fall (May 20 and May 

 21, respectively). Trees in both blocks are on M.7 

 rootstock. The Clarkdale block consisted of 

 Golden Delicious and Mcintosh, about 15 years 

 old, with rows running east-west, and the Alyson's 

 block was Mcintosh and Empire, about 12 years 

 old, with rows running north-south. 



This was an unusually wet year in the North- 

 east. In a more typical year we would not reach 

 the 'North Carolina' threshold until early August, 

 but in 1998, we reached this threshold by early 

 July. Over 100 hours of wetness occurred during 



a single week in June. The specific threshold dates 

 were: at Clarkdale Orchards, the New York thresh- 

 old of 150 hours from the last apple scab fungi- 

 cide was reached on June 22, and the North Caro- 

 lina threshold of 200 hours was reached on July 3. 

 At Alyson's Apple Orchard, the New York thresh- 

 old was reached on June 24, and the North Caro- 

 lina threshold on July 2. Because the New York 

 threshold at Clark's was reached at the same time 

 that he was planning a 'standard' spray, both the 

 'standard' and 'New York' plots were treated on 

 the same date. 



The first summer fungicide applications were 

 made on June 22, June 22, and July 9 at Clarkdale 

 for the standard program, NY program, and NC 

 program, respectively. The first summer fungicide 

 applications were made on June 24, July 2, and 

 July 16 at Alyson's for the standard program, NY 

 program, and NC program, respectively. 



At Alyson's, Mr. Goodband decided to test a 

 yet more radical approach than what we had origi- 

 nally proposed. The fungicide application on June 

 24 actually coincided with the NY threshold, and 

 the July 2 date was when the 200-hour NC thresh- 

 old was reached. The application on July 16 was 



14 



Fruit Notes, Volume 63 (Number 4), Fall, 1998 



