Igr Evaluation Experiment 2,1996

This experiment was conducted in a 2.5 acre block of 130-yr-old trees on M 7A rootstock. Trees measured 11 ft. in height and 10 ft. in width and were planted at a spacing of 20 X 20 ft. The experimental design consisted of 4 replications (2 ‘Delicious’, 2 ‘Criterion’) of 9-tree plots (3 rows X 3 trees/row) in a randomized block design. Insecticides were applied as complete sprays to both sides of the trees with a Swanson DA500A airblast sprayer, which traveled at 2.3 mph and delivered a spray volume of 100 gal/acre. Dates (plant growth stage and degree-days after 1st pheromone trap catch in spring of CM, TABM, OFM) of application were 10 May (petal fall, 163,-, 296), 22 May (302, 161, 489), 3 Jun (410, 317, 644), 11 Jun (561, 508, 835), 26 Jun (900, 921, 1248), 11 Jul (1191, 1285, 1613), 25 Jul (1499, 1641, 1969), 8 Aug (1754, 1989, 2317), 21 Aug (1976, 2274, 2602), 30 Aug (2144, 2488, 2815), and 5 Sep (2237, 261 1, 2938). Other materials applied separately to all treatments were Agri-Mycin, Asana, COCS, Dithane, Nova, Penncozeb, Topsin-M, and Ziram. Treatments were evaluated by counting arthropod pests and injury on the periphery of the center tree in each plot periodically during the season. Control of WALH was determined by counting nymphs on the underside of 25 leaves per tree. OFM control was determined by counting injured terminals per tree. Effect of treatments against ERM was determined by sampling 25 leaves/tree, removing mites with a mite-brushing machine, and counting motile stages with a binocular microscope. Control of STLM was determined by counting all tissue-feeding mines during a 5 minute period per tree. Effect of treatments against TABM was determined by counting leaf shelters and live larvae within leaf shelters per tree. Control of fruit-feeding insects was determined by scoring for injury 100 picked apples/replication on 24 Sep.