Apple, Insect Control, 1983

Test materials were applied to mature ‘Cortland’ apple trees (planted 40 ft by 40 ft apart) as dilute sprays (ca. 8 g per tree). We used a randomized complete block design, with four single-tree replications per treatment. Applications were made with a handgun at 450 lb/in2 to all plots on 17 and 26 May, 9 and 24 June, 8 and 21 July, and 6 Aug. All treatments included Captan 50 WP (2 lb/100 gal) in the first three sprays and Cyprex 65 WP (0.5 lb/100 gal) in the remaining sprays. European red mite (ERM) populations were assessed by sampling 25 leaves per tree, collected at chest height around the periphery of the tree, and brushing mites onto glass plates treated with Tween 20 in the laboratory. Rosy apple aphid (RAA) infestations were evaluated by counting the number of curled clusters per tree. Potato leafhopper (PLH) and green apple aphid evaluations were made by counting the number of infested terminals per tree. Woolly apple aphid (WAA) infestations were evaluated by counting the number of colony-infested terminals per tree. Major direct-fruit insect damage was evaluated by randomly picking a minimum of two bushels of fruit per tree on 13 Sept. and evaluating damage by specific insects.