Effects of Timing on Efficacy of Halofenozide (RH034S) and Imidacloprid (Merit) Against White Grubs, 1996

Abstract

This test was conducted on mature, low-maintenance Kentucky bluegrass turf at the University of Kentucky Spindletop Farm, near Lexington. The turf was on a Maury silt loam soil (Ph = 6.4) with negligible thatch. Plots (6 X 6 ft) were arranged in a RCB design with 4 replicates. Treatments were applied once a month in Jun, Jul, and Aug. Granular formulations were preweighed, mixed with dry sand, and applied by gloved hand. Liquid applications were applied at 50 gpa using a low volume, CO2 sprayer equipped with 4 Spraying System 8004 Tee Jet nozzles that delivered 2109 g pressure per cm2. The whole site received 1/2 inch irrigation as soon as the last treatment was applied. Conditions during application were 85, 86 and 89°F, respectively, with winds < 10 mph for all applications. The site received natural rainfall between treatments as well as post-treatment irrigation after all applications. Plots were sampled on 17 Sep by cutting a 3 X 1.5 foot strip, about 3 inches deep, from the center of each plot with a motorized sod cutter. Sod was rolled back, broken apart, and examined for grubs which were counted and identified.