Efficacy of Registered and Experimental Insecticides for Control of European Corn Borer Under Artificial Infestation, 1996

Corn was planted at the Shaw Foundation Farm, Champaign, IL in rows 30 inches wide on 17 Jun. A RCB design was used, and each treatment was replicated four times. Two untreated controls were used per replication and averaged for the analysis. Each plot was 4 rows wide X 60 ft long. Insecticides were applied to the middle 2 rows of each plot; the 2 outside rows were left untreated. Treatments were applied with a modified John Deere 6000 high-clearance vehicle (HCV) with a rear-mounted boom. Granules were applied through Noble units mounted in brackets on the rear of the HCV. The Noble units were driven with electric motors, and the granules were applied over the whorls in a 7-inch band. Liquid insecticides were broadcast over the center 2 rows of the 4-row plot with TeeJet even fiat-fan spray tips (8003VS) mounted in brackets on the rear of the HCV. The height of the nozzles was approximately 18 inches above the whorls. The liquids were delivered with a compressed-air system calibrated to deliver 11.0 gpa at 20 psi at a speed of 2.5 mph. Plants were artificially infested with ECB on 18 and 19 Jul. Two black head stage ECB egg masses were placed in the whorl of 15 consecutive plants in each of the middle 2 rows of a 4-row plot on each of the 2 infestation dates. On 26 Aug, 10 of the infested plants from each of the middle 2 rows in each plot were split with a corn knife for evaluation. The number of borer cavities and the total length of cavities per plant were recorded. The mean percentage of plants with cavities and percent control were determined for each treatment.