Full-Season Insecticide Evaluations, 1988

Insecticide treatments were applied in a comparative test to mature ‘York’ trees on 6 Apr (only treatments scheduled for delayed dormant application), 14 Apr (P, pink), 11 May (PF, petal fall), 1 June (1C, first cover), 17 June (2C, second cover), 8 Jul (3C, third cover), 28 Jul (4C, fourth cover), and 31 Aug (5C, fifth cover). Treatments were applied with a Bean 35 gal/min hydraulic sprayer operating at 300 psi. Single-tree treatments were replicated 4 times in a randomized block design. Trees were sprayed to run-off. AA populations were evaluated on 21 Jun by randomly selecting 10 growing terminals/replicate, rating aphid populations on a scale of 1-5, and counting aphids on the fourth distal leaf. ERM populations were evaluated on 13 Jul and 15 Aug by randomly selecting 25 leaves/replicate, brushing them with a modified Henderson-McBurnie brushing machiin . and cropting motile mites and viable eggs with a binocular microscope. WALH damage was evaluated by rating foliage on each tree on a scale of 1 (low) to 5 (high). Insect feeding on fruit was evaluated by harvesting 100 apples/replicate on 3 Oct and visually inspecting each apple.