Whorl Applications to Control Fall Armyworm in Corn, 1987

Abstract

Abstract 'Silver Queen' sweet corn was planted 13 Jul in a Sassafras sandy loam field. Plots were 4 rows wide on 30-inch centers and 25 ft long. Treatments were replicated 4 times in a randomized complete block design. Granular whorl treatments were applied with a hand shaker in a 7-inch band over the whorl on 18 and 24 Aug. No other treatments were applied. Twenty whorls were rated for fall armyworm damage on 26 Aug as follows: 0, no damage; 1, slight damage, up to 10% whorl feeding; 2, moderate damage, 10-25% whorl feeding; 3, heavy damage, 25-50% feeding damage; 4, severe damage, 50-75% whorl feeding, tassel damaged; and 5, whorl destroyed. Twenty whorls were removed from the plants, unrolled, and all live armyworm larvae were counted. On 6 Oct, 20 ears were harvested and weighed. On 16 Oct, 20 plants in each plot were measured to determine plant height from the soil surface to the tip of the tassel. On 19 Nov, 10 stalks from the center 2 rows of each plot were split from 3 nodes above the ear to 3 nodes below the ear and each 2.5 cm of ECB damage was recorded as one cavity.