High Pressure Liquid Injection of Imidacloprid for the Control of Mole Cricket Nymphs, 1997

Abstract

Abstract A field efficacy trial was performed to evaluate the timing and placement of imidacloprid (Merit 75 WP) applications for the control of mole cricket nymphs. Plots 16 ft X 70 ft were established on a heavily infested bermudagrass fairway at the Fox Squirrel Country Club in Brunswick Co, NC. Treatments were replicated four times and randomly assigned to the plots. The first insecticide treatments (egglay/hatch) were applied on 4 Jul. The 4-inch soil temperature on this date was 88°F. Air temperature was 93°F. Broadcast applications were made using a CO2-powered backpack sprayer delivering 30 gpa. Subsurface treatments were applied using a self-propelled SGI™ Subsurface Injection System to inject the liquid insecticide mixture to a depth of 1 inch using high-pressure (2800 psi) pulses. At this depth the equipment applies approximately 1.0 gal/100 ft2. Insecticides were injected every 4 inches in 4-inch strips to produce a 4-inch X 4-inch treatment pattern. According to the equipment’s designer, the insecticide spreads out below the soil surface into a circular treatment area approximately 1 inch in diam. The fairway irrigation system was used to apply 0.25 inch of water to the entire test site immediately after application. The same equipment was used again on 31 Jul to apply the subsurface treatment directed against early and midsize nymphs. Soil was moist at the time of application and the 4-inch soil temperature was 75°F. Soil at the test site was classified as a Kureb fine sand with a pH of 5.8 and 0.56% humic matter. Soapy water flush sampling of areas adjacent to the test indicate that the fairway population was approximately 85% SB and 15% SV. Plots were evaluated for fresh damage on 14, 20 Aug, and 10 Sep using the damage grid evaluation method of Mack and Cobb (1989). A m2 grid divided into nine subsections was placed randomly in each plot and a damage rating (0-9) given depending on the number of subsections in which fresh damage was observed. Five damage ratings were taken in each plot on each sampling date. Actual damage means are presented in the Table. All data were transformed x + 0.5 prior to ANOVA and Tukey’s Studentized Range Test.