Spring Control of Northern Masked Chafer Grurs on a Golf Course Rough in Dillsrurg, Pa., 1987

Abstract

Abstract The rough consisted primarily of annual bluegrass (60%), Kentucky bluegrass (30%), and perennial ryegrass (10%). Treatment plots were 9 × 6 ft, arranged in a randomized complete block design and replicated 3 times. Liquid formulations were applied by using a C02 sprayer with 4 8004VS Teejet nozzles mounted on a 6-ft boom, operating at 28 psi and delivering 5 gal/1000 sq ft. Three Diazinon treatments were applied in a split application; 2 lb (AI)/acre of each formulation was applied on the 28 April and again 7 days later (5 May). At treatment time (28 April), the following soil and environmental conditions existed; air temperature, 48°F; soil temperature, 58°F; RH 68%; amount of thatch, 0.25-0.75 inches; soil type, silt loam; soil size separation, 16.2% sand, 63.6% silt, 20.2% clay; % soil moisture, 18.0; soil pH 5.3; % organic matter, 2.9; water pH, slightly acidic; 1.5 inches of rainfall was recorded over the posttreatment period. The following conditions existed on 5 May for the second split application of Diazinon treatments: air temperature, 63°F; soil temperature 54°F; RH, 64%. The experimental area was irrigated immediately after treatment with 0.25 inches of water. Posttreatment counts were made 24 days later (22 May). Three sq ft sod samples were randomly taken from each replicate, and the total number of northern masked chafer grubs/sq ft was recorded. An average of 8.0 northern masked chafer grubs/sq ft was recorded on 28 April.