Subsurface Placement and Surface Application of Insecticides for Control of Japanese Beetle Larvae on a Golf Course Fairway in Lucas County, Oh, 1993

Two studies were located side by side on a golf course fairway at Toledo, OH. Insecticides were applied 30 Aug to plots 12 ft (3.66 m) in length × the width allowed by the application equipment (3 or 4 ft wide) arranged in a RCB replicated 4 times. Granular insecticides were placed in two passes using a Cushman Ryan1® prototype subsurface applicator. The prototype cut 11 slits into the turf on 2 inch (5.1 cm) centers and deposited granules Vi to 1 inches (ca 2 cm) deep. Liquid products were subsurface placed with one pass using a modified Rain Saver Jr™ liquid polymer injection machine at a 3.34 gal/1000 ft2 (1360 1/ha) volume. The machine cut 16 slits in the turf 2 inches (5.1 cm) apart placing the solution Vi to % inches (ca 2 cm)into the thatch-soil profile. Surface sprays were applied using a CO, sprayer with Teejet 8015 nozzles at 55 psi (3.87 kg/cm2) pressure that delivered a volume of 3.32 gal/1000 ft2 (1352 liter/ha). Surface application of granules were made in two passes with a two foot Gandy drop spreader. All surface treatments were hand irrigated with ½ inch (13 mm) water immediately after each plot was treated. The site received 0.1 inch rainfall within 18 h after applications were made. Environmental conditions at time of treatment were as follows. JB larvae: ca. 194/m2, 10% 1st, 70% 2nd, 20% 3rd instars. Turf: level, dry, 34 inch (2 cm) height, mix of Kentucky bluegrass, annual bluegrass, and bentgrass. Thatch: dense, ½ inch (13 mm) moist. Soil: moist, 90°F at 1 inch (2.5 cm) and 83°F at 3 inches (7.6 cm). Weather: sunny, 91°F, 3-7 mph (5-11 km/h). Water: pH 4.9. Efficacy data taken 6 Oct (37 DAT) were based on the number of live JB larvae in six 7 inch × 7 inch (17.8 × 17.8 cm) square samples from each plot. No phytotoxicity or excessive equipment damaged was observed.