Control of Winter Grain Mites in Rye Grass Turf, 1982

The experimental site consisted of a stand of 100% improved rye grass surrounding a commercial office building in Whitehall, OH. Several locations on the property showed heavy mite damage on Apr 16 and active adults were easily visible in the thatch and on the foliage. Environmental conditions at the time of application were as follows: air temperature, 55 F; relative humidity, 90%; wind from the south at 5-10 mph; overcast skies; and moist soil conditions. Mowing height of the turf was 2.5-3 in. Six treatments replicated 4 times were applied to 5 ft × 10 ft (1.5m × 3m) experimental plots arranged in a RCB design. Applications were made Apr 17 using a CO2 pressurized sprayer with three 9520 nozzles mounted on a 5 ft aluminum bloom, operating at 25 psi with a 4 gal/1000 ft2 spray rate. None of the treatments was 2 irrigated following application. Rainfall 4 DAT was ca 0.09 in. Pretreatment counts showed.a range of 450 to 1660 mites/ft . The experimental plots were evaluated at 4 DAT by randomly taking 4 cup-cutter plugs (0.1 ft) from each plot and extracting the active WGM's/plug in a Berlese funnel for 24 hr (25 watt bulb).