Evaluation of Insecticides for Boll Weevil Control in Mississippi, 1986

Abstract

Abstract Four treatments were tested for relative efficacy against Boll Weevil in nonirrigated cotton planted 19 May. Plots 8 rows (38 inch centers) by 50 ft long, separated by 15 ft plowed alleys were located at the Plant Science Research Farm, Mississippi State University, Starkville, MS. Treatments were arranged in a randomized complete block design with 4 replications and 4 cages per replication. Total spray volume was 5 gal/acre at 4 mph and 38 psi. Plots within a replication were sprayed consecutively with the boom being rinsed twice and blown clear between plots. Prior to insecticide application, 4 sleeve cages 44 inches in diam by 28 inches long, fabricated from a light cotton-acetate blend material, were tied in each block by tying the lower end of each cage around a plant ca. 1.5 ft from the terminal, rolling the sleeve down and covering it with aluminum foil to protect if from spray. Immediately following spray application on 8 Jul, the cages were rolled up over treated plants and 10 live laboratory-reared boll weevils were inserted into each cage. The cages were then secured with a string. After 24 hr of exposure the plants with cages were cut from the field and brought to the laboratory where boll weevil mortality was determined. Weevils were classified as live if they kicked actively when submerged in warm water. The study was repeated at 1, 3, and 6 days post treatment.