Colorado Potato Beetle Control on Potatoes with NTN-33893, 1991

Abstract

Abstract 'Superior' potatoes were planted in 20 foot rows on 15 and 17 Apr, '91. Both planting dates had identical treatments. Plots consisted of single treatment rows. The distance between rows was 36 inches and the distance between plants within the row was 9 inches. Plots were arranged in a randomized complete block design with 4 replications. The soil was a Norfolk “A” loamy sand. Granular treatments were applied with a small shaker can over the top of seed pieces in the furrow. In furrow spray treatments were applied to the seed pieces at the rate of 20/gal per acre with a one pint bottle with a trigger pump. All treatments were applied at planting. In evaluating the teatments, direct counts of the number of Colorado potato beetle adults, larvae and egg masses/5 stems and 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 & Hills 1978). Dry conditions prevailed for much of the growing season.