Management of Annual Bluegrass Weevil with Preventive and Curative Treatments of Chlorpyrifos, Cyfluthrin, and Imidacloprid Formulations on a Golf Course Fairway, 1997

Abstract

Abstract The study was conducted in Bedford County, PA. The fairway consisted primarily of annual bluegrass (70%) and Kentucky bluegrass (30%). Applications were made before, during, and after egg lay. Treatment plots were 5 X 6 ft, arranged in a RCB design and replicated 4 times. Liquid formations were applied with a CO2 compressed-air sprayer with four 8002VS TeeJet nozzles mounted on a 6-ft boom, operating at 28 psi, and applied in 227 ml of water/30 ft2 or delivering 2 gal water/1,000 ft2 on 15 Apr and 7 May. Applications completed on 23 Jun were applied in 7 qt of water in a hand-held sprinkling can. At the 1st treatment time, (15 Apr), the following soil and environmental conditions existed: air temperature, 51° F; soil temperature at 1-inch depth, 57° F; soil temperature at 2-inch depth, 46° F; RH, 70%; amount of thatch, 0.25 inch; soil textural class, clay loam; soil particle size analysis: 20.7% sand, 51.0% silt, 28.3% clay; soil percent water content (percent of weight), 33.3%; organic matter, 10.0%; water pH, 7; soil pH, 5.7; application time, late morning; and partly cloudy skies. Treatments were irrigated in with 0.1 inch of water immediately after treatment. At the 2nd treatment time (7 May), the following soil and environmental conditions existed: air temperature, 51° F; soil temperature at 1-inch depth, 56° F; soil temperature at 2-inch depth, 49° F; RH, 74% amount of thatch, 0.25 inch; soil textural class, clay loam; soil particle size analysis: 20.6% sand, 50.9% silt, 28.5% clay; soil percent water content (% by weight), 32.8%; organic matter, 8.9%; water pH, 7; soilpH, 6.1; application time, mid morning; and clear skies. Treatments were irrigated in with 0.1 inch of water immediately after treatment. At the 3rd time (23 Jun), the following soil and environmental conditions existed: air temperature, 78° F; soil temperature at 1-inch depth, 80° F; soil temperature at 2-inch depth, 78° F; RH, 69%; amount of thatch, 0.25 inch; soil textural class, silty clay loam; soil particle size analysis: 18.8% sand, 52.6% silt, 27.6% clay; soil percent water content (percent by weight), 34.5%; organic matter, 10.5%; water pH, 7; soil, 6.3; application time, mid morning; and clear skies. A total of 9.73 inches of rain was recorded from May 2 through Jun 27, and 2.0 plus inches of snow was recorded from Apr 18 through Apr 25. Post-treatment counts were made on 27 Jun. Annual bluegrass weevil control was evaluated by removing two 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.