Sweet Corn Insect Control in Illinois, 1990

Abstract

Abstract 'Gold Cup' sweet corn was planted 3 Jul at the University of Illinois Vegetable Crops Farm, Champaign. Plant spacing was 30 inches with 26,100 plants/acre. Plots consisted of 2 rows × 50 ft, with 25-ft alley ways between each replication. The design was a complete randomized block with 4 replications. Insecticide applications were made to the 2 middle rows with the outer 2 rows left untreated. In the insecticide efficacy trial, applications were made on 23, 25, 28, 31 Aug and 3 Sep corresponding to 0, 2, 5, 8, and 11 d after the first appearance of silks (DAS). In the Capture 2 EC spray-timing study, the insecticide was applied only once (2 DAT), twice (2 and 5 DAT), or 3 times (2, 5, and 8 DAT). Insecticide applications were made with a modified John Deere 6000 (HCV). A 10-ft boom equipped with Conejet TXSS12 hollow cone nozzles (2 nozzles/ row on 30-inch drop pipes) was mounted on the rear of the HCV. Sprays were directed at the ear zone of the plants. Treatments were delivered with a compressed-air system calibrated to deliver 31.4 gal/acre at 60 psi at a speed of 3 mph. On 14 Sep, 25 ears were collected from the 2 middle rows in each plot on 14 Sep. Each ear was examined for insect damage and classified as (1) no insect damage, (2) damage only on the tip, (3) damage only on the side, and (4) tip damage is extended to at least 1.5 inches to the side or both tip and side damage present. The number of ECB, CEW, and FAW larvae on or in the ear was also recorded.