Apple, Early Season Insecticide Trials, 1982

Materials were applied to mature York trees as follows: delayed dormant (Mar 23); pre-pink (Apr 2); pink (Apr 20); 1st cover (May 21); 2nd cover (Jun8). Single tree plots were arranged in a randomized block design and replicated 4 times. Treatments were sprayed to runoff using a handgun operating at 400 psi. Treatments were evaluated for effects on rosy apply aphid populations on May 3 and May 13. All colonies on each tree to a height of 10 feet that could be found in a 15 minute search were counted. European red mites were counted on May 3 to evaluate effects of treatments on early populations. Ten leaves per tree (40/treatment) were randomly selected and motile mites were counted under a hand lens. Scale was evaluated at harvest (Sep 9) by randomly selecting 50 apples from the top and 50 apples from the bottom of each tree. Data are presented as percent of fruit infested in each section of the tree.