Abstract
Abstract Cotton was planted 2 Jun with plots consisting of 4 rows (40 inch centers) × 50 ft. Treatments were arranged in a RCBD, replicated 4 times. Applications were made with a high clearance sprayer calibrated to deliver 6 gal total spray/acre through Teejet X-8 hollow cone nozzles (2/row) at 46 psi. Insecticides were applied on 9, 12, 15, 22 Aug and 1 Sep. Treatments were evaluated by examining 50 squares per plot on 12, 15, 19, 26 Aug for evidence of bollworm-tobacco budworm and boll weevil damage. The data reported for boll weevil are a summary of across sample dates. High numbers of soybean looper and beet armyworm larvae were observed in the plots during Sep and visual defoliation ratings were used to evaluate treatments on 21 Sep. Each plot was scored as follows: 0 (no feeding damage), 1 (feeding damage within the lower Vi of the plant), 2 (feeding damage in the lower Vs and middle % of the plant) or 3 (feeding damage throughout the plant). The plots were mechanically harvested on 25 Oct to determine seedcotton yields. The test area received 0.1, 1.9, 0.6 and 0.2 inches rainfall on 14, 21 Aug, and 2, 7 Sep, respectively. Supplemental moisture was provided by sprinkler irrigation “as needed” during the season, but not within 48 h of treatment applications.
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