Efficacy of Conventional and Microbial Insecticides for Sweet Corn Insect Control, 1991

• Published in: Insecticide and acaricide tests 1992-01, Vol.17 (1), p.107-107
• Main Authors: Oloumi-Sadeghi, H., Royer, T. A., Randell, R.
• Format: Article
• Language: English
• ISSN: 0276-3656
• DOI: 10.1093/iat/17.1.107

Four conventional insecticides and a single formulation of Bacillus thuringiensis were evaluated for efficacy against ECB and CEW. Sweet corn was planted 3 Jul at the University of Illinois Vegetable Crops Farm, Champaign. Plant spacing was 30 inches with 26,100 plants per 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 of each plot. Applications were made on 28 and 31 Aug and 3, 6, and 9 Sep (corresponding to 1, 3, 6, 9, and 12 days after the first appearance of silks). Insecticide applications were made with a modified John Deere 6000 (HCV). A 10-ft boom equipped with Conejet TXSS12 hollow cone nozzles (2/row on 30-inch drop pipes) was mounted on the rear of the HCV. Sprays were directed at the ear zone of plants. Treatments were applied with a compressed-air system calibrated to deliver 30 gal/acre at 60 psi. Twenty-five ears were collected from the 2 middle rows in each plot on 12 Sep. Each ear was examined for damage and classified as (1) no insect damage, (2) damage only on the tip, (3) damage only on the side, and (4) tip damage extending at least 1.5 inches to the side or both tip and side damage. The number of ECB and CEW on or in the ear was also recorded.