Apple, Full Season Insecticide Evaluations, 1983

Experimental insecticide treatments were applied in a comparative test to mature semidwarf trees on 5 Apr. (delayed dormant), 27 Apr. (pink), 25 May, 8 June, 23 June, 19 July, 3 Aug., and 25 Aug. Treatments were applied with a Bean 35 gal/min hydraulic sprayer operating at 400 lb/in2. Single tree treatments were replicated four times in a randomized block design. Trees were sprayed to runoff. White apple leafhopper populations were evaluated on 2 7 May by counting nymphs and adults on 10 leaves per replicate. European red mite populations were evaluated on 8 July, 27 July, and 22 Aug. by randomly selecting 10 leaves per replicate and counting motile mites with the aid of a hand lens. Stethoruspunctum (LeConte) was evaluated on 28 July and 23 Aug. by counting larva and adults in a timed count of 3 min per replicate. Fruit evaluations for insect damage were completed at harvest (30 Sept.) by examining 50 randomly selected fruit from each replicate. Percent clean fruit for each treatment was recorded. Fruit finish was rated on a scale of 1 (lowest) to 5 for each apple and averaged for the four replicates.