Wireworm Control on Potato, 1987

Abstract

Abstract Certified 'La Rouge' seed pieces were planted on 10 Dec in a Perrine marl soil and spaced 4 inches apart in rows that were 3 ft apart. Thirteen treatments were arranged into a randomized complete block design with 4 replications. Treatment plots were 4 rows by 40 ft long. Plants were fertilized with 800 lb/acre of granular fertilizer (8:20:8) at planting and an additional 1300 lb/acre of liquid fertilizer (4:4:12) during the growing season. Maneb was applied (1.5 lb [AI]/acre) weekly and Benlate 50WP was applied (1.0 lb [AI]/acre) on 2 dates to control foliar plant pathogens. Insecticide treatments were applied on 4 dates. Dyfonate was applied with a 10-ft-long Gandy applicator and incorporated into the soil with a disk harrow on 9 Dec. Thimet was applied directly to the seed pieces in the furrow at planting with a planter-mounted Gandy applicator. Postemergence applications of Vydate and Di-Syston were made on 17 Jan using fumigator knives that delivered 150 gal/acre at 3 mph directly to the root zone 8 inches off center on both sides of each hill. Thimet was applied 8 inches off center to both sides of each hill using a tractor-mounted, chain-driven Gandy applicator and incorporated into the soil with a rolling cultivator after plant emergence on 19 Jan. Vines were killed on 14 Mar with Paraquat Plus (1 qt/acre; 29.1% [AI]/acre). Two 25-ft sections of row per treatment plot were harvested on 7 Apr. Tubers were washed, graded for wireworm injury (holes less than threequarters' inch in depth), damage (holes greater than three-quarters' inch in depth), cracking, sunburn, disease, etc., and weighed fresh. Data for injury damage, sunburn, and cracking are presented as a percentage of total fresh weight/section of row. Before planting, 190 soil samples and 72 baited traps were removed to characterize the wireworm species complex in the field.