Insecticidal Control of European Corn Borer and Corn Earworm in Sweet Corn, 1996

This test was conducted on the University of Minnesota Southern Experiment Station at Waseca, MN. Sweet corn was planted 1 Jul. Plots consisted of 4 rows, 25 ft (7.6 m) long on 30 inch (0.8 m) centers with 2 untreated border rows and 6-ft (1.83 m) alleys separating plots. Treatments were arranged in a RCB design with 4 replications. A Hagie highboy sprayer, with two flat fan (8002VS) drop nozzles per row, was used to treat each plot. The nozzles directed spray over the oar zone of each row. The sprayer was calibrated to deliver 35 gpa (327.4 liters/ha) at 36 psi (2.8 kg/cm2) and 2 mph (1.2 km/hr). Treatment applications began at first silk. Treatments were applied 13, 21 and 29 Aug. Plots were manually infested with about 25 neonate ECB larvae per primary ear-leaf on 22 Aug, 1 day after the second treatment application. Treatments were evaluated 9 Sep by randomly selecting 25 ears per plot (100 per treatment) and recording total number of larvae, larval size, location and feeding damage. In addition to the manual infestation, 14% of the plants were infested with 1 or more feral ECB egg masses at first silk.