Influence of Application Timing of Insecticides on Control of Southern Masked Chafer, 1997

Abstract

Abstract This study was conducted in Lincoln, NE, on a golf course rough. The turf (50% Kentucky bluegrass and 50% perennial rye) was maintained at a mowing height of 2.0 inches. Thatch accumulation (finger compressed) in the plot area was 0.75 inch. Field conditions at the study site were; soil type, silty clay loam; soil organic matter, 3.5%; soil pH, 6.5; water pH, 7.0. Environmental conditions at the time of application, (17 Jun, and 12 Aug) were as follows: soil moisture 20%, and 22% by wt respectively; air temperature 84° F, and 64° F; soil temperature 65° F, and 66° F; relative humidity 32%, and 88%; wind direction and velocity 245° at 3 mph., and 345° at 7 mph. Plots were 6 X 10 ft and the experimental design was a RCB with 4 replications. Liquid insecticides were applied using a CO2 sprayer with a TeeJet® 8002 nozzle at 30 psi and delivering 87 gpa. Following applications, plots were irrigated with 0.25 inches of water. Post-treatment precipitation totaled 8.34 inches. Treatments were evaluated 80 days after the first application on 05 Sep by removing from each plot six, 8-inch diam turf-soil cores (2.10 ft2 total area) to a depth of 3 inches and counting the number of surviving grubs.