Preventive Management of Annual Bluegrass Weevil with Halofenozide, and Imidacloprid Formulations on a Golf Course Fairway, 1997

Abstract

Abstract The fairway consisted primarily of annual bluegrass (70%) and Kentucky bluegrass (30%). Applications were made before 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 8002VS TeeJet nozzles mounted on a 6-ft boom, operating at 28 psi, and applied in 272 ml of water/36 ft2 or delivering 2 gal water/1,000 ft2. Granular formulations were applied with a hand-held shaker with top-dressing sand used to provide even distribution of product. At treatment time (15 Apr), the following soil and environmental conditions existed: air temperature, 50°F; soil temperature at 1-inch depth, 57°F; soil temperature at 2-inch depth, 46°F; RH, 70%; amount of thatch, 0.25-0.375 inch; soil textural class, silt loam; soil particle size analysis: 18.1% sand, 78.3% silt, 3.6% clay; soil percent water content (percent by weight), 32.7%; organic matter, 10.7%; water pH, 7; soil pH, 5.9; application time, late morning; and partly cloudy skies. The experimental area was irrigated with 0.1 inch of water immediately after treatment. A total of 10.14 inches of rain was recorded from 25 Apr through 25 Jun, and 2.0 plus inches of snow was recorded from 18 Apr through 25 Apr. Post-treatment counts were made on on 25 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.