Subsurface Placement of Granular Insecticides for White Grub Control, 1990

Abstract

Abstract This study was conducted in Lincoln, NE, on a golf course fairway. The predominant grass species was perennial ryegrass maintained at a mowing height of Ys inches. Thatch accumulation (finger compressed) in the plot area was 0.25 to 0.5 inch. 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 near field capacity throughout the study. Plots were 5 x 10 ft and the experimental design was a randomized complete block with 4 replications. Insecticide treatments were applied on 6 Aug using either a Ryan Mataway Overseeder modified to place insecticide granules at an avg depth of 0.24 inches, or a Gandy 30H12 drop spreader. Immediately following applications, some plots were irrigated with 0.5 inch of water. No additional water was applied for 72 h after treatment. An additional 1.4 inches of irrigated water was applied and 3.18 inches of rain fell during the post-treatment period. Treatments were evaluated 21 DAT on 27 Aug by removing from each plot six, 8-inch diam turf-soil cores (2.1 ft2 total area) to a depth of 3 inches and counting the no. of surviving grubs.