Colorado Potato Beetle Control on Potatoes, 1993

Abstract

Abstract ‘Kennebec’ potatoes were planted in 20 foot rows on 8 Apr, ’93. Plots consisted of a single treatment row. The distance between rows was 64 inches and the distance between plants within the row was 10 inches. Plots were arranged in a randomized complete block design with 4 replications. The soil was a Norfolk “ A ” loamy sand. All spray treatments were mixed in 1.5 gallons of water and applied with a custom built compressed air row crop sprayer. Each row was covered by 6 drop nozzles delivering 50 gal/ acre at 28 psi. Treatments were applied 21, 27 May; 2, 9, 14, 16, and 22 Jun. Trigard treatments were applied 21 May; 2 and 14 Jun. Novodor was applied 21 and 27 May. These same plots were treated with Kryocide thereafter on 2, 9, 14 and 16 Jun. Plots were treated with Vydate 2L 0.75 lb AI/ acre on 22 Jun to control Colorado potato beetle adults. In evaluating the treatments, direct counts of the number of Colorado potato beetle adults, larvae and egg mass/10 plants and the % defoliation were recorded. Defoliation categories were assigned using a pretransformed defoliation rating scale, based on dividing 90° into 13 steps corresponding to arcsin transformation values (Little & Hill 1978). Yields were taken on 28 Jul from 20 feet of row.