Caterpillar Control on Sweet Corn, 1980

Abstract

Abstract ‘Silver Treat’ sweet corn were planted Jul 7 ‘80 to a Sassafras sandy loam field. Plots were 4 rows wide on 30 in centers and 25 ft long. Granular systemic treatments were banded in the furrow at planting; granular whorl treatments were applied with a hand shaker over the whorl; whorl sprays were applied with a tractor-mounted boom sprayer with one nozzle centered over the row calibrated to deliver 30 gal/A at 40 psi; and foliar sprays at silking were applied with a tractor-mounted boom sprayer with 4 nozzles/row, directed at the ear zone, which delivered 85 gal/A at 250 psi. Whorl treatments were applied Aug 8 and 15; foliar sprays at silking were applied Aug 29, Sep 2, 5, 8 and 11. Twenty plants/plot were evaluated on Aug 18 for armyworm damage. The categories for armyworm foliar injury damage are as follows: 1) slight feeding; 2) 10% feeding; 3) heavy feeding, 25% of whorl damaged; 4) whorl destroyed, 50% defoliation; and 5) skeletonized, whorls destroyed. At harvest, Sep 15, 20 ears from the middle 2 rows of each plot were evaluated for ‘worm’ damage as “none” (clean), “tip” (< 1 1/2 in tip damage) and “side”. On Oct 15, 20 stalks and ear shanks in each plot were split from 3 nodes above the ear to 3 nodes below the ear; each inch of damage was recorded as 1 cavity.