Annual Bluegrass Weevil Management on a Golf Course Fairway with Chlorpyrifos and Bifenthrin Formulations, 1997

Abstract

Abstract The fairway located in Bedford County, PA, consisted primarily of annual bluegrass (70%) and Kentucky bluegrass (30%). Applications were made when flowering dogwood was in full bloom. Treatment plots were 6 X 5 ft, arranged in a RCB design and replicated 5 times. Granular formulations were applied with a hand-held shaker with top-dressing sand used to provide even distribution of product. Liquid formulations 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 wa-ter/30 ft2 or delivering 2 gal water/1,000 ft 2. At treatment time (2 May), the following soil and environmental conditions existed: air temperature, 61° F; soil temperature at 1-inch depth, 54° F; soil temperature at 2-inch depth, 64° F; RH, 45%; amount of thatch, 0.125-0.25 inches; soil textural class, clay loam; soil particle size analysis: 21.2% sand, 43.8% silt, 35.0% clay; soil percent water content (percent by weight), 42.8%; organic matter, 11.1%; soil pH, 6.1; water pH, 7; application time, mid-morning; and clear skies. The experimental area was irrigated with 0.1 in of water immediately after treatment. A total of 9.83 inches of rainfall was recorded from 2 May through 30 Jun. Post-treatment counts were made on 30 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 than converted to a ft2 count.