Apple, Petal Fall Insecticide Applications, 1984

Test materials were applied to 13-year-old trees at Monmouth, Maine, as dilute sprays using a hand gun and a hydraulic sprayer operating at 250 psi at 300 gal/acre. Trees were sprayed on 3 Jun (petal fall). The fungicide program consisted of Difolatan 4F (5 qt/100 gal) on 29 Apr. There were 4 single-tree replications for each treatment. A randomized complete block design was used. Except for test trees, the orchard was not sprayed with insecticides. On 30 Aug, 0.5 box of apples was picked from each tree, and about 480 apples were examined per treatment on 8 Sep for typical feeding injuries by MLB and egg-laying scars by PC. On 2 dates MLB counts were taken by rapping a fruit cluster over a plastic box; on 21 Jun, 20 clusters were sampled per tree and on 9 Jul, 10 clusters. ERM were counted on 1 date on 25 leaves collected mostly at chest-height around the periphery of each tree. Leaves were brought into the laboratory and brushed onto glass plates coated with a Tween 20 and alcohol mixture; mites were counted the same day. The first half of Jun was very warm.