Foliar Sprays to Control the Corn Earworm, European Corn Borer and Corn Earworm in Sweet Corn

Abstract ‘N & K 199’ sweet corn was planted, 10 inch spacing in 3 ft rows, on June 1, 1975. Treatment plots were replicated 3 times and arranged in a randomized block design. Each plot consisted of three 25 ft long rows with a single untreated row adjacent to each treatment plot. Insecticides were applied to the ear area with a D. B. Smith 5 gallon knapsack, hand-operated compressed air sprayer at the rate of 25 gal/A (40 psi), using a Spraying Systems ConeJet Y8 nozzle. Treatments were initiated just prior to first silk on July 28 and continued at 2 to 3 day intervals through August 13-8 treatments in all. On August 20, twenty-five ears from each treatment replicate were checked for earworm, European corn borer and fall armyworm injury. Earworm damaged ears were divided into 2 classes: 1) Medium - Damage to 1.5 inches from tip, ear could be clipped; and 2) Severe - Damage well beyond ear tip and of such nature that ear could not be clipped or salvaged for use. Corn borer and fall armyworm infested ears were not graded into classes but merely recorded as infested or uninfested. A measure of the overall effectiveness against the 3 pests was determined by recording the number of unmarketable ears per 25 ears examined.