Apple, Insect Control, Hudson Valley, Highland, New York, 1982

Abstract

Abstract Treatments were applied to 8 tree plots replicated 3 times in a randomized complete block design. Treatments were applied at pink, May 4; petal fall, May 17, 18, and in 5 cover sprays, Jun 3, 22, Jul 9, 23, and Aug 12, using a handgun sprayer at 400 psi delivering 4.2 gal spray/tree (403 gal/acre) dilute to runoff. Trees were 18-yrs-old, ca 12 ft high, on EM2 rootstock, and spaced 15 × 30 ft. Orthene treatments were only applied during the first 3 sprays, Guthion being used in the plots the remainder of the season. Ambush was only applied during the first 2 sprays, Cymbush being applied during the remaining sprays. Plictran 50WP at 8 oz formulation/100 gal was applied Jul 9 with all treatments except SIR 8514, Payoff, and FCR 1272. SLJ 0312 50WP at 8.0 oz formulation/100 gal was applied Jul 9 with the FCR 1272 treatment. Vangard 10WP 7.5 oz/acre was applied May 3, 27, and Jul 7 while Rubigan 1EC 9.0 oz/acre was applied Jun 15 over the entire block with an airblast sprayer at 4X (100 gal/acre) concentration. Thinning sprays were applied dilute by handgun using from 5-15 ppm of Naphthaleneacetic acid (depending upon the cultivar) on May 26. The weather was dry through the bloom period but June was unusually wet, while August was cooler than normal. Pest populations were at normal levels throughout the season. Insect damage was assessed by examining 100 fruits/cultivar/plot from 'Mcintosh' Sep 14, 'Cortland' Sep 17, 'Empire' Sep 24, and 'Golden Delicious' Sep 28.