Summer Control of Japanese Beetle Grubs on a Golf Course Fairway in Lewistown, Pa., 1987

Abstract

Abstract The fairway consisted primarily of annual bluegrass (40%), Kentucky bluegrass (30%), and perennial ryegrass (30%). Treatment plots were 9 × 6 ft, arranged in a randomized complete block design and replicated 3 times. Liquid formulations were applied by using a CO2 sprayer with 4 8004VS Teejet nozzles mounted on a 6-ft boom, operating at 28 psi at a spray rate of 5 gal/1000 sq ft. Granular formulations were applied with a hand-held shaker, and mixed with a fine grade of sand top dressing to facilitate product distribution. Three Diazinon treatments were applied in a split application; 2 lb (AI)/acre was applied on 25 Aug and again 7 days later (1 Sep). At treatment time (25 Aug), the following soil and environmental conditions existed: air temperature, 68°F; soil temperature, 79°F; RH, 55% amount of thatch, 0.25-0.75 inches; soil type, loam; soil size separation, 40.2% sand, 43.6% silt, 16.2% clay; soil moisture, 26.3% soil moisture, soil pH 5.4; % organic matter, 3.0; water pH, slightly acidic; 4.85 inches of rainfall was recorded over the posttreatment period. The following conditions existed on 1 Sep for the second split application of Diazinon treatments: air temperature, 63°F; soil temperature, 61°F, RH, 85% % soil moisture, 20.3. Immediately after treatment the experimental area was irrigated with 0.5 inches of water. Posttreatment counts were made 25 days later (19 Sep). Three sq ft sod samples were randomly taken from each replicate, and the total number of Japanese beetle grubs/sq ft was recorded.