Granular and Liquid Insecticide Performance Against Black Cutworm, 1992

Abstract

This trial investigated the performance of granular insecticides at below-label rates applied at planting, rescue applications of liquid insecticides and a nematode (BioVector). Experimental plots were established in continuous corn field with a Waukegan silt loam soil at the Rosemount Agricultural Experiment Station. Plots measuring rows (76-cm row spacing) x 9 m, were arranged in a RCB design with 4 replications. Corn was planted on 20 May at a seeding rate of 64,500 seeds/ha. Granular treatments were applied at planting ahead of the presswheel using modified Noble applicators. Aluminum barriers, each surrounding 4.6 cm of 2 rows and extending 10 cm below and 15 cm above the soil, were installed 8 Jun when corn was just emerging. Corn stand within the barriers averaged 40 plants. On 9 Jun between 6 and 7 p.m. each plot was infested with 60 BCW larvae (50% 4th, 50% 3rd instars). The next morning, between 7-9 a.m., all liquid rescue treatments were applied within the appropriate barrier arenas. Liquid insecticides were applied in 187 liters of water/ha while the nematodes (BioVector) were applied in 750 liters/ha. Wind speed ranged from 0 to 3 km/h, while soil temperatures hovered near 22°C. Plots were examined 3, 6, and 10 d after infestation, injured plants were marked and plant injury was recorded as leaf feeding. Statistical analyses were performed after determining the final fate of each plant.