Apple, Insecticide Evaluation, 1987

Abstract

Abstract Insecticides were applied to 6 single-tree plots (3 'Rome Beauty,' 3 'Golden Delicious') of 33-yr-old trees in a randomized block design. Applications were made with a Swanson DA500A airblast sprayer, which traveled at 3.86 km/h and delivered 935 liters/ ha. Dates of application were 9 Apr (delayed dormant [DD]), 14 Apr (tight cluster [TC]), 21 Apr (prepink [PP]), 7 May (petal fall [PF]), 26 May (first cover [1C]), 11 Jun (second cover [2C]), 25 Jun (third cover [3C]), 8 Jul (fourth cover [4C]), 23 Jul (fifth cover [5C]), 6 Aug (sixth cover [6C]), 20 Aug (seventh cover [7C]) and 3 Sep (eighth cover [8C]). Other materials applied separately to all treatments were Bayleton, Benlate, Bordeaux mixture, Captan, Manzate 200, Polyram, and Streptomycin. Control of RAA was determined by counting colonies on the periphery of each tree. WALH control was evaluated by counting nymphs found on 25 leaves selected from the periphery of each tree. Effect of treatments on ERM was determined by sampling 33 leaves from the periphery of each 'Rome Beauty' tree, removing mites with a mite-brushing machine and counting active stages with a binocular microscope. Treatment effect on S. punctum was determined by counting adults and larvae observed on the periphery of each 'Rome Beauty' tree during a 3-min period. Effect of treatments on fruit-feeding insects was determined by scoring for injury 600 apples per treatment (100/replication) and all fallen apples sampled on 28 Sep. Fruit picked from 'Golden Delicious' trees were rated for finish (0-5 worst).