Corn Borer Insecticide Efficacy Trial, 1989

Abstract

Abstract This experiment was conducted in a furrow-irrigated corn field at the Southwest Research-Extension Center. Treatments were arranged in a randomized complete block design with 4 replications. Plots were 4 rows wide (10 ft), 50 ft long with a 10 ft border of untreated corn on each side and a 10 ft alley between plots. The simulated chemigation applications were made using 3 Delavan 100/140, 0.75 inch rain drop nozzles mounted on a high clearance sprayer at tassel height between rows. This system was calibrated to deliver the equivalent of a 0.16 inch irrigation on the 2 center rows (4374 gal/acre). The standard treatments were applied with a high clearance sprayer using a 10 ft boom with 3 nozzles directed at each row (one nozzle directly over the row and one on each side of the row on 18 inch drop hoses). The sprayer was calibrated to deliver 20 gal/ acre using a ground speed of 2.3 mph and 30 psi. Treatments of Andalin, Dimilin, and Capture were applied on 7 Aug and all other treatments were applied on 9 Aug. The Lorsban treatments received additional applications on 21 and/or 29 Aug. Corn borer counts were made between 15 Sep and 2 Oct by dissecting 15 corn plants from the center 2 rows of each plot. The number of larvae, the number of tunnels, and length of tunneling was recorded for each plant.