Apple, Summer Control of Pandemis Leafroller, 1985

Abstract

Abstract A 10-year-old apple orchard was used to evaluate timing of 2 insecticides in controlling larvae of apple pandemis. Insecticides were applied as dilute sprays to the point of drip (approximately 400 gal per acre) using a handgun sprayer at 400-500 psi. Five single-tree replicates were used for each material and timing in randomized complete block design. Two unsprayed treatments were included. Lorsban and Penncap-M were initially applied at first egg hatch on 25 Jun (800 degree days after first codling moth flight). The second and third treatments were applied 200 and 460 degree days after the first spray on 8 Jul (1000 degree days after first codling moth flight) and 18 Jul (1460 degree days after first codling moth flight), respectively. The sine-wave method was used to calculate degree days using the same lower (50 F) and upper (88 F) temperature thresholds used for codling moth. All evaluations were made on 22 Jul. The number of live larvae on each tree was recorded.