Fall Applications of Sulfonylurea Herbicides for Poa annua Control and Turfgrass Safety

Certainty, Monument, and TranXit gave variable Poa control in the spring at 6 to 8 months after applications that were made prior to fall overseeding. There was not consistent Poa control with respect to timing of applications from one month to two weeks before overseeding. Most Poa control in February or April was marginally acceptable at 85% control or less. Common bermudagrass treated with the sulfonylurea herbicides was affected with observable reduced quality. The ryegrass density at 10 days after first water appeared to be less for all treatments compared to the untreated check. At one month after overseeding, all plots had ryegrass well-established and quality ratings were comparable to the untreated check for all treatments