Sub-Surface Vs. Conventional Application of Turcam for Control of Japanese Beetle Grubs on Golf Course Rough, 1991

Abstract

Abstract An experiment using two methods of sub-surface application of pesticides was conducted on a golf course rough in Bolton, MA. The rough consisted primarily of Kentucky bluegrass (50%), perennial ryegrass (30%), and annual bluegrass (20%), and was maintained at a mowing height of 5.0 cm until 3 d before application. At that time the turf was mowed to 1.9 cm and clippings removed. Thatch remaining averaged 1.9 cm with a moderate density. Insecticides were applied on 5 Sep to 1.7 × 4 m plots arranged in a complete randomized block design. Each plot was separated from the next by 0.3 m, and there was a 3 m border between replications. Conditions at the time of application were as follows: air temperature 25°C; general overcast with high humidity; soil type, silty loam; soil moisture moderate; soil pH, 6.5; water pH, 6.4. Liquid treatments were applied using a High Pressure Liquid Injection (HPLI) research unit (built by Cross Equipment Co., Albany, GA), delivering 1,650 PSI through nozzles at 7.5 cm spacing, 1000 liters/ha, 5.6 kmph or with a watering can, using 3 liters water per plot. Granules were applied using a Cushman overseeder prototype, delivering granules through slices cut 1.9 cm (soil/thatch interface) with 5 cm spacing between slices or with hand-held shakers with perforated lids. All plots were watered in with 0.6 cm irrigation immediately after application and an additional 0.6 cm 12 h after application. Product efficacy was evaluated 28 DAT (4 Oct) by cutting two 0.1 m2 samples out of each plot, dislodging soil with a hand trowel, and counting all grubs to a depth of 10 cm.