Control of Annual White Grubs with Entomopathogenic Nematodes and Conventional Insecticides, 1993

The study was conducted in Lincoln, NE on a Kentucky bluegrass golf course rough. The turf (100% Kentucky bluegrass) was maintained at a mowing height of 1.5 inches and thatch accumulation in the plot area was 0.5 inches (finger compressed, 0.25 inches). Field conditions at the time of application were: soil type, silty clay loam; soil organic matter, 3-5%; soil pH, 6-7; water pH, 7.0; soil moisture, near field capacity. Plots were 6 × 6 ft, and the experimental design was a RCB with 4 replications. Insecticide treatments were applied 31 Aug. Liquid formulations were applied with a CO, sprayer using an LF-4 tip at 24 psi and delivering 3 gal finished spray/1000 ft2. Granular insecticides were applied with a pre-calibrated Gandy 24H12 spreader. Immediately following applications, the test area was irrigated with approximately 0.5 inches of water. A total of 1.48 inches of rain fell during the post-treatment period. Product efficacy was evaluated 23 Sep (23 DAT) 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 number of surviving grubs.