Transitioning overseeded bermudagrass (Cynodon dactylon) back to a monoculture in spring often leads to thin turf with poor aesthetics. Past efforts that used low herbicide rates were not effective at improving turfgrass aesthetics while controlling perennial ryegrass (Lolium perenne). In efforts to improve turfgrass playing conditions during transition, we have developed a process that stimulates bermudagrass growth with minimal impact on turfgrass quality. By applying selective herbicides with specially designed equipment, we can partially control perennial ryegrass without disrupting playing conditions or visual appeal of turf. The result is numerous tiny openings in the perennial ryegrass canopy that is scarcely noticeable to the average golfer or other client. These openings stimulate nearby bermudagrass to grow and increase bermudagrass cover in advance of the normal transition time.

A randomized complete block trial with three replications was conducted at Farmington Country Club near Charlottesville, VA in 2006. Research studies included three herbicide application methods: drip, sponge, and strip. Treatments included two transition herbicides, foramsulfuron (Revolver at 29 g ai/ha) and trifloxysulfuron (Monument at 23 g ai/ha). The drip boom and sponge applicator were calibrated to kill 6-cm diameter circles on 10-cm centers. Calibrations were unique for each device and resulted in a solution delivery rate of 1,635 L/ha for drip, 1,402 L/ha for sponge, and 280 L/ha for strips.