Comparison of Mach-2 and Tempo for Residual Control of Black Cutworm on Bentgrass, 1997

Abstract

Abstract This trial was conducted at Amherst Country Club, Amherst, NH. Four replicates of each treatment were laid out on a bentgrass nursery. At 4-, 2- and 1 -week intervals prior to installation of larvae, the insecticides were applied on their respective areas. Liquid formulations were applied with a 2-wheel bicycle-type CO2 boom sprayer equipped with 4 spray nozzles; each nozzle was fitted with an 8005 fan-type nozzle and a 50-mesh strainer. The volume of water and insecticide mix per plot was 2 gal/1000 ft2 delivered at 40 psi. Granulars were evenly dispersed using large commercial-style salt shakers, and were irrigated to approximately 1/4-inch of water per plot. Weather conditions on each spray date were as follows: 4-week interval (25 Jul): air temp, 66°F; sky, overcast; soil surface temp, 66°F; at 1-inch depth, 67°F; at 2-inch depth, 66°F; 2-week interval (8 Aug): air temp, 72°F; sky, mostly sunny; soil surface temp, 70°F; at 1-inch depth, 68°; at 2-inch depth, 66°; 1-week interval (15 Aug): air temp, 66°F; sky, cloudy; soil surface temp, 67°F; at 1 -inch depth, 66°F; at 2-inch depth, 65°F. Soil analysis resulted in the following: texture, loam; sand, 44%; silt, 38%; clay, 18%; soil pH, 5.7; moisture, 21%; organic matter, 5%. PVC cylinders were installed in all plots, and 19 3rd-instar larvae were put into each cylinder on 22 Aug. The trial was rated at 1-, 3-, and 7-day intervals after installation of larvae by applying a mixture of Joy dish soap and water to each cylinder to force live larvae to the surface for counting.