Foliar Sprays to Control Corn Earworms in Sweet Corn, 1978

'N&K 199' was planted, 10-inch spacing in 3-ft rows, on May 18. Treatment plots were replicated 3 times and arranged in a randomized block design. Each plot consisted of 3 rows 25 ft long with a single untreated row adjacent to each treatment plot. Insecticides were applied to the ear and to areas about 15 inches above and below the ear with a D.B. Smith 5-gallon, knapsack, handoperated, compressed-air sprayer at the rate of 25 gal/acre (40 psi), using a Spraying Systems Cone Jet Y-8 nozzle. Treatments were initiated at first silk on Jul 17 and continued at 2-3 day intervals thru Jul 31, a total of 7 applications overall. Twenty-five ears were harvested from each treatment replicate on Aug 4 and checked for earworms. The following categories were selected for evaluation of corn earworm injury: 1)Clean - no evidence of earworm; 2)Slight - confined to silk or extreme tip of ear; 3)Medium - injury less than 1.5 inches below tip; ear could be clipped; and 4)Severe - damage well below ear tip and of such nature that ear could not be clipped or salvaged for use.