Field Evaluation of Insecticides for the Control of Black Cutworm in Field Corn, 1980

Abstract

Abstract This test was conducted on a high organic soil poorly drained field which has had a history of a black cutworm problem for the past ten years. Corn was planted on May 13 in a commercial field located near Selbyville, DE. Plots of 6 x 25 ft were replicated 4 times In a randomized complete block design. The seed treatment was applied as a slurry mixture to a measured amount of seed. Dyfonate 4E was applied as a broadcast pre-planr incorporated treatment. The remainder of the at-planting treatments were applied on May 14. All granular insecticides except Mocap 10G were applied as a 7-in band over the row with a 1 row Gandy applicator. Mocap was applied as a 12-in band over the row. Granular treatments were lightly incorporated using a drag chain. Vydate L was applied as a 8-in band over the row using the wheel barrow type sprayer described below. Pelletized baits were applied to the appropriate plots by hand broadcasting premeasured amounts. Rescue spray treatments were applied on May 30 using a wheel barrow design, CO2-pressurized sprayer with a single flood jet nozzle directing a 15-in spray band over each row delivering 19 gal/acre at 30 psi. Plots were artificially infested with black cutworm larvae (third to sixth instars) at a rate of 10 per 15 ft of row between the middle two rows on May 28. Pretreatment standcounts were taken on 12 ft of row (6-in from each of the middle two rows) on May 28 followed by the artificial infestation of larvae. Standcounts and the number of cut plants per 12 ft of row were recorded on May 30, June 3, June 9, and June 18. No cut plants were observed on June 18 and as a result no significant data was obtained. Corn was harvested from the middle two rows of the plot and yield data was obtained on October 8.