Whorl Applications to Control Fall Armyworm in Sweet Corn, 1983

Abstract

Abstract ‘Silver Queen’ sweet corn was planted 14 July in a Sassafras sandy loam field. Plots were 4 rows wide on 30-in centers and 25 ft long. Treatments were replicated four times in a randomized complete block design. Granular whorl treatments were applied with a hand shaker in a 7-in band over the whorl; whorl sprays were applied with a self-propelled, high-clearance sprayer with one nozzle centered over each of the middle two rows calibrated to deliver 55 gal/acre at 200 lb/in2. Treatments were applied on 19, 25, and 31 Aug. Plant whorls were rated for fall armyworm damage on 2 Sept. as follows: 0, no damage; 1, slight damage, 10% whorl feeding; 2, moderate damage, 10 to 25% whorl feeding; 3, heavy damage, 25 to 50% whorl feeding, 4, severe damage, 50 to 75% whorl feeding, tassel damaged; and 5, whorl destroyed. Twenty plant whorls were removed from the plants, unrolled, and all live fall armyworm larvae were counted.