Efficacy of Vydate for Control of Boll Weevil and Cotton Fleahopper, 1983

Abstract

Abstract A large-plot field test was conducted on the Kocurek Farm near Corpus Christi, TX, to evaluate the efficacy of Vydate for control of boll weevil. Cotton was planted the first week in Mar on rows spaced 38 inches apart. Field plots (8 acre/plot) were replicated 3 times in a completely randomized design. Applications were made in 5 gal total spray/acre with a John Deere high clearance ground machine on 20, 25, and 30 May. The entire test was oversprayed with Bidrin on 5 and 24 May at 0.1 lb (AI)/acre. Boll weevil damage was determined by collecting 3 samples of 50 squares (1/3 grown and larger) and 50 bolls (ca. 7-days old) per plot per sample date. The 3 samples were averaged to represent a replicate for statistical analysis. Bollworm larvae and damage were assessed by collecting 3 samples of 50 squares and bolls as above. Terminal counts of fleahoppers and blasted squares, and beat bucket samples for beneficials were determined by sampling 50 plants per plot. Fruiting counts, yields, earliness and fiber properties were determined by sampling ca. 6 ft of row at 4 sites per plot. An additional study on boll weevil survival study was conducted by caging female boll weevils on Guthion and Vydate (0.25 lb [AI]/acre) treated plants 5 days post-treatment. Following egg laying, females were removed and the cages left in place for 8 days. All punctured squares were counted and held in the laboratory for boll weevil emergence.