Subsurface Applications for Control of Annual White Grubs on a Golf Course Fairway, 1994

Abstract

Abstract This study was conducted in Lincoln, NE on a golf course fairway. The turf (100% Kentucky bluegrass) was maintained at a mowing height of ⅝ inches. Thatch accumulation (finger compressed) in the plot area was 0.5 to 0.75 inches. Field conditions at the study site were: soil type, silty clay loam; soil organic matter, 3-5%; soil pH, 6.7; water pH, 7.0. Soil moisture was maintained at approximately 16% by weight, throughout the study. Plots were 40 inches × 15 ft and the experimental design was a RCB with 3 replications. Insecticide treatments were applied on 24 Aug 1994 using a Cushman prototype subsurface applicator designed to place liquid insecticide treatments at the soil-thatch interface (avg depth 0.75 inches). Following applications, plots were irrigated with 0.5 inches of water. Post-treatment precipitation totaled 0.42 inches. Treatments were evaluated 21 DAT on 14 Sep by removing from each plot three, 8-inch diam turf-soil cores (1.05 ft2 total area) to a depth of 3 inches and counting the no. of surviving grubs. Pretreatment counts indicated 10-40 SMC/ft2 with 80-90% in the third instar stage in the test area.