| Abstract/Contents: | "This trial was conducted on a lawn at Woodman Horticultural Research Farm, Durham, NH. Each treatment was replicated four times, in 49-ft2 plots, in a RCB design. Two full rates of Allectus G and one rate of Merit 2SC were applied on 1 Jun. One full rate, and three half-rates of Allectus G were applied on 15 Jun. Two full rates, and two of the second half-rates of Allectus G of the 15 Jun applications, one rate of Arena 50WDG, and one rate of the Merit 0.5G were applied on 28 Jun. The remaining second half-rate of Allectus G was applied on 5 Aug. Two rates of the Allectus G, and one rate of the Merit 0.5G were applied on 25 Aug. The cut-ht of the grass was generally 2.5 inches on all application dates. The grass was cut once a wk, or on an as needed basis. Grass clippings were raked from the plots prior to each application. The dry granulars were applied with large salt shakers. The aqueous solutions were applied by a 7-ft boom on a bicycle-type sprayer. The boom was equipped with four 8005 flat-fan pattern spray nozzles, fitted with 50-mesh screens. The material was delivered by CO2 pressure, at 40 psi. The vol of insecticide and water mix was 2 gal/1000 ft2. All treatments on all application dates were hand watered to approximately 0.25 inch. The soil type was the following: texture, sandy loam; sand, 55%; silt, 31%; clay, 14%; organic matter, 6.5. Weather and soil conditions were the following: (1 Jun) sky, overcast; wind, calm; air temp, 64°F; soil surface temp, 69°F; at 1-inch depth; 67°F; at 2-inch depth, 66°F; pH, 6.0; moisture, data not available; (15 Jun) sky, light mist; wind 5-8 mph; air temp, 51°F; soil surface temp, 59°F; at 1-inch depth, 61°F; at 2-inch depth, 62°F; pH, 5.8; moisture, 22%; (28 Jun) sky, hazy sun; wind, less than 5 mph; air temp, 84°F; soil surface temp, 90°F; at 1-inch depth, 85°F; at 2-inch depth, 85°F; pH 6.0; (5 Aug) sky, hazy sun; wind, less than 5mph; air temp, 90° soil surface temp, 92°F; at 1-inch depth, 82°F; at 2-inch depth, 80°F; pH, 6.0; moisture, 12%; (25 Aug) sky, partly cloudy; wind, less than 5 mph; air temp, 76°F; soil surface temp, 86°F; at 1-inch depth, 84°F; at 2-inch depth, 82°F; pH 5.7; moisture, 14%. There was 0.54 inch of rain within 24 hr prior to 15 Jun applications, but no rain within 24 h prior to all other applications dates. Within 24 h after applications, there was 0.1-inch for 15 Jun, 0.2-inch for 28 Jun, and 0.2-inch for 5 Aug; there was no rain within 24 h after 1 Jun and 25 Aug applications. The trial was rated for live AGB larvae on 2 Nov. A Ryan sod cutter, equipped with a 12-inch-long cutting blade, was used to cut down the center of the plots, 2 inches deep. Afterwards, 2 ft2 of turf from each plot was rolled back to reveal the AGB larvae. Data were subjected to ANOVA and means were separated using DMRT (P ≤ 0.05). Allectus G at 0.36 lb applied 1 Jun and 15 Jun was not significantly different from the untreated check. Allectus G applied at 0.45 lb on 1 Jun, 28 Jun and 25 Aug gave excellent control, as well as the standard Merit. Split applications of Allectus G at 0.225 lb in June provided the same degree of control as a single application at 0.45 lb. Arena 50WDG at 0.25 lb applied on 28 Jun equaled the performance of Allectus G at 0.45 lb and Merit at 0.3 lb. Low grub counts may have prevented better statistical separation of the treatments." |
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