Comparison of Three Rates of a Growth Regulator on Black Cutworm, 1996

Two trials were conducted at Amherst Country Club, Amherst, NH. In the first trial treatments were applied on 6 Sep to a bentgrass nursery and rated 13 Sep. In the second, treatments were applied 12 Sep and rate 19 Sep. The treatments were applied in an RCB design, 4 replicates per treatment, with 1 -ft buffers between plots. All treatments were applied with a 2-wheel bicycle-type CO2 boom sprayer, using four 8004 nozzles with 50-mesh screens. The volume of water and insecticide mix per plot was 2 gal/1000ft2 delivered at 40 psi. BCW larvae were predominantly 3rd-4th instar in the 1st trial and 1 st-2nd instar in the 2nd trial. Weather conditions were as follows: on 6 Sep, air temp, 81°F; sky, clear; wind, calm. Soil conditions were as follows: surface temp, 83°F; temp at 1-inch depth, 74°F; soil pH, 5.7; dry matter, 80%; moisture, 20%; organic matter, 4%; soil texture, loam; sand, 60%; silt, 20%; clay, 20%. On 12 Sep, air temp was 74°F; soil temp at surface was 71°F; at 1-inch depth, 69°F. The trials were rated for live larvae by soaking each plot with Joy dish soap and water to force larvae to the surface.