Evaluation of Granular Formulations of Insecticides for Control of Japanese Beetle and Northern Masked Chafer Grubs on a Golf Course Rough in Franklin County, Ohio, 1991

Experimental plots consisting of approximately 80% Kentucky bluegrass and 20% perennial ryegrass were established and treated on 29 Jul. Treatment plots were 3.05 m squares, separated by 0.9 m alleys, arranged in a randomized complete block design and replicated 4 times. Liquid treatments were applied using a C02 sprayer (40 psi with four 8015 Teejet nozzles) calibrated to deliver 0.16 liter/m2, and granular products were applied using a 0.61 m Gandy Turf Tender drop spreader. The entire experimental area was irrigated with 6.35 mm water (7.96 pH) immediately after treatments were applied. At treatment time, conditions were: sky cloudy, air temperature 24.4°C, wind 0-19 km/h, soil temperature at 2.5 cm = 26.7°C and at 7.6 cm = 25.0°C, and the turf had a dense thatch 6.35-12.7 mm thick, with mowing height 4.4 cm. Posttreatment counts were made 58 d later (25 Sep) by taking six 17.8 × 17.8 cm (= 0.03 m2) samples randomly from each treatment plot and recording the number and species of grubs.