| Abstract/Contents: | "In the summer of 1986, several postemergence grass herbicides were applied to several growth stages of barnyardgrass, corn and sorghum. Spray carrier was 26 gpa with 1 qt/A of 411 F type crop oil concentrate. Barnyardgrass was growing in postemergence trials with cotton, sunflowers, soybeans, and sugarbeets; corn and sorghum were planted in some of the trials to simulate volunteer crop growth. Experiments were randomized blocks with three replications. The soil was silt loam with 16, 59, and 25 percent of sand , silt and clay; pH of 7.8 and 1.2% organic matter. Three rates of each herbicide were sprayed. Rates of application in lb/A were: Fusilade 2000 and Whip, 0.12, 0.18, 0.25; Poast, 0.2, 0.3, 0.4; BAS 517, 0.1, 9.15, 0.2; Assure, 0.03, 0.06, 0.09; DPX 6202-31, 0.016, 0.032, 0.045; Verdict, 0.06, 0.12, 0.25; and Select, 0.06, 0.12, 0.18. Barnyardgrass heights ranged from 1.5 to 16 inches. Corn and sorghum height ranged from 4 to 18 inches. With the exception of the tallest barnyardgrass and crops, soil moisture and plant vigor were excellent at treatment. Pounds per acre of herbicide that gave at least 95% control of 1.5-. 2.5- and 16- inch barnyardgrass, resectively, were: Fusilade 2000, 0.12, 0.12, >0.25; Poast, 0.2, 0.3, >0.4; BAS 517, 0.1, 0.15, >0.2; Assure, 0.03, 0.09, >0.09; DPX 6202-31, 0.016, 0.045, >0.045; Verdict, 0.06, 0.06, 0.025; Select, 0.06, 0.06, >0.18; and Whip, 0.12, 0.12, 0.25. The > sign indicates the highest rate applied. However, this rate did not give 95% control. Rate in lb/A to give 95% or more control of 12-inch corn was: Fusilade 2000, 0.12; Poast, 0.2; BAS 517, 0.1; Assure, 0.03; DPX 6202-31, 0.016; Verdict, 0.06; Select, 0.12; and Whip, 0.12. It required higher rates of Poast, Bas 517, DPX 6202-31, Verdict, and Whip to control 6-inch corn than 12-inch. Four-inch sorghum was controlled 95% with the following lb/A: Fusilade 2000, 0.25; Poast, >0.3; BAS 517, 0.15; Assure, 0.03; DPX 6202-31, 0.016; Verdict, 0.12; Select, -.12; and Whip, 0.012." |
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