Wireworm Control on Potato, 1989

Abstract

Abstract Certified ‘La Rouge’ seed pieces were planted on 16 Dee in a Perrine marl soil and spaced 10 cm apart in rows that were 0.9 m apart. Sixteen treatments were arranged into a randomized complete block design with 4 replications. Treatment plots were 4 rows by 9.1 m long. Plants were fertilized with 896 kg/ha of granular (8:20:8) at planting and an additional 1456 kg/ha of liquid (4:4:12) during the growing season. Maneb 80 was applied (1.7 kg [AI]/ha) weekly and Benlate 50 was applied (1.1 kg [AI]/ha) on two dates to control foliar plant pathogens. Insecticide treatments were applied on three dates. Parathion was applied with a 9.1 m long Gandy applicator and incorporated into the soil with a disc harrow on 16 Dec. Thimet 20 G (4.0 kg [AI]/ha) was applied directly to the seed pieces in the furrow at planting on 16 Dec with a planter-mounted Gandy applicator. Thimet 20 G (2.0 kg [AI]/ha) and Force 1.5 G (0.1 and 0.3 kg [AI]/ha) were applied in the furrows 3 days after planting. Post-emergence applications of Thimet 20 G were also made 8 inches off center to both sides of each hill using a tractor-mounted, chain-driven Gandy and incorporated into the soil with a rolling cultivator after plant emergence on 17 Jan. Post-emergence applications of Vydate and Disyston 8 were made on 19 Jan using fumigator knives that delivered 1402 liter/ha at 4.8 km/h directly to the root zone 8 inches off center on both sides of each hill. Vines were killed on 13 Mar with Paraquat Plus (2.3 liter/ha; 29.1% [AI]). Two 6.1 m sections of row per treatment plot were harvested on 19 Apr. Tubers were washed, graded for wireworm injury (holes less than 1.9 cm in depth), damage (holes greater than 1.9 cm in depth), cracking, sunburn, disease, etc., and weighed fresh. Data for injury, damage, sunburn, and cracking are presented at a percentage of total fresh weight/section of row.