Control of Annual White Grubs Using Subsurface Placed Soil Insecticides and Entomopathogenic Nematodes, 1991

Abstract

Abstract This study was conducted on a Kentucky bluegrass lawn in Lincoln, NE. Plots were 40 inches × 15 ft and the experimental design was a randomized complete block with 4 replications. The turf was maintained at a mowing height of 1.5 inches and thatch accumulation (finger compressed) in the plot area was 0.5 to 0.75 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, 15%. Insecticide treatments were applied on 8 Aug using a newly developed Cushman prototype Subsurface Applicator to place insecticides or entomophagous nematodes at the soil/thatch interface (average depth 0.63 inch). Immediately following application, plots were irrigated with 0.25 inch of water. An additional 3 inches of irrigated water was applied and 0.1 inch of rain fell during the posttreatment period. Treatments were evaluated 21 DAT (3 Sep) by removing from each plot six, 8-inch diam turf-soil cores (2.1 ft2 total area) to a depth of 4 inches and counting the number of surviving grubs.