Suppression of Annual Bluegrass Weevil on a Golf Course Fairway with Split Applications of Chlor-Pyrifos and Experimental Formulations, 1996

Abstract

Abstract The fairway consisted primarily of annual bluegrass (70%) and Kentucky bluegrass (30%) in Bedford County, PA. Applications were made when flowering dogwood was in full bloom. Treatment plots were 6 X 6 ft, arranged in a RCB design and replicated 4 times. Liquid formulations were applied with a CO2 compressed air sprayer with four 8004VS TeeJet nozzles mounted on a 6 fi boom, operating at 28 psi, and applied in 272 ml of water/36 ft2 or delivering 2 gal water/1,000 ft2. At the 1st treatment time (14 May), the following soil and environmental conditions existed: air temperature, 57°F; soil temperature at 1 inch depth, 64°F; soil temperature at 2 inch depth, 60°F; RH, 35% amount of thatch, 0.25-0.50 inches; soil textural class, loam; soil particle size analysis: 27.4% sand, 46.9% silt, 25.8% clay; soil moisture (oven dry weight) 46.6%; organic matter, 6.8%; water pH, 7; soil pH, 5.9; application time, mid-morning; and clear skies. The experimental area was irrigated with 0.1 inch 24 hr after treatment. At the 2nd treatment time (31 May), the following soil and environmental conditions existed: application time, late-morning; air tem perature, 61°F; soil temperature at 1 inch depth, 64°F; soil temperature at 2-inch depth, 58°F; RH, 48%; amount of thatch, 0.25-0.50 inch; soil texturai class, loam; soil particle size analysis: 27.4% sand, 46.9% silt, 25.8% clay; organic matter, 6.8%; soil condition, moist; water pH, 7; soil pH, 5.9; and cleai skies. The experimental area was irrigated with 0.1 inch 1 hr after treatment. Post-treatment counts were made on 19 Jun. Annual bluegrass weevil con trol was evaluated by removing three 4-inch cup cutter sod samples from each replicate and recording the total number of annual bluegrass weevil life stages (larva, pupa, adult) per sample. Totals were then converted to a ft2 count.