Codling Moth Control, Large Plots, 1984

Abstract

Abstract This test was conducted near Wenatchee at the Columbia View orchard, a part of the Tree Fruit Research Center. The orchard consisted of Red Delicious trees in their fifth leaf on a semi-dwarfing rootstock. The orchard was sprinkler irrigated with an undertree, solid-set system. Each treatment was applied to an unreplicated half-acre block of trees using a handgun sprayer at 400 psi to the point of drip simulating a dilute spray of ca 400 gal per acre. Dimilin was first applied 17 May at 75 degree days after first moth (PFM) caught in pheromone traps. The second application was made 12 Jun. Guthion was first applied 12 Jun at 250 degree days PFM. The second Guthion application was made 3 Jul. Evaluation of first generation injury was made on 13 Jul. All fruit on each tree were examined in the border and adjacent 3 rows (32 trees/plot). The number of apples injured by codling moth was recorded. There was heavy codling moth pressure throughout the orchard. Dimilin was applied against the second generation of codling moth on 30 Jul at 1450 degree days PFM. Guthion was applied against second generation on 7 Aug at 1650 degree days PFM. All fruit in the border and next 3 rows were examined for injury on 30 Aug. A single mite sample of 50 leaves from each plot was taken on 22 Aug. Data are presented as average mites per leaf.