Apple, Comparison of Insecticides Against Oblr, 1995

Treatments were applied with a truck-mounted airblast sprayer to 0.25 acre plots of apple trees in two orchards: (1) ‘Idared’, ‘Cortland’ and ‘Empire’ trees (VanFleet orchard), which were ca. 4 years old, 5 ft high, and planted 8 by 12 ft apart; (2) ‘Idared’ (Nesbitt orchard), which were ca. 8.0 ft high and planted 15 by 18 ft apart. Treatments were arranged in a RCB design and replicated twice in each orchard. Complete seasonal schedules of Asana, Dipel, Lorsban, and Confirm were compared in which the first spray was applied at the estimated first OBLR egg hatch (21-23 June), followed by 2 more protective sprays at 14-d intervals. Early schedules of Asana and Confirm were compared in which only 1 spray was applied at the estimated first egg hatch (21-23 June). Also, a 2-spray schedule of Asana was tested in which the first spray was applied at the estimated first egg hatch (21-23 June) followed by one more spray 14 d later. Application volume was 100 gpa. Summer populations of larvae were compared by examining 20-50 growing terminals from each of 5 randomly selected trees/plot for live larvae on 11-12 Jul and on 25-26 Jul. Fruit damage from the first summer generation of larvae was estimated on 6-7 Aug and on 21-22 Aug by sampling 100-150 apples from each of 5 randomly selected trees/plot. Similar fruit samples were collected at harvest in each plot and classified in USDA grades of Fancy, #1, and culls.