Late summer goosegrass control is difficult in turfgrass as POST herbicide efficacy is reduced on mature plants. Field experiments were conducted to evaluate single and sequential nicosulfuron applications tank-mixed with foramsulfuron or sulfentrazone for late summer goosegrass control and safety to bermudagrass and seashore paspalum. All single-treatment applications controlled goosegrass < 62%, whereas sequential sulfentrazone, nicosulfuron, and nicosulfuron sulfentrazone applications controlled goosegrass 52, 73, and 84%, respectively. Sequential foramsulfuron applications controlled goosegrass < 55% but nicosulfuron tank-mixtures did not improve control. Bermudagrass was injured < 20% by 1 and 3 wk after all single and sequential treatments. Sequential treatments of nicosulfuron alone or tank-mixed with sulfentrazone caused unacceptable seashore paspalum injury (> 20%) 1 and 3 wk after the second application, whereas foramsulfuron or sulfentrazone alone applied sequentially caused < 17% injury. Seashore paspalum seedhead control at 9 wk after intial treatment was poor (< 70%) from all single-application treatments and sequential sulfentrazone applications, but control was good (80 to 89%) to excellent (> 90%) from all other treatments. Overall, sequential treatments of nicosulfuron alone or tank-mixed with sulfentrazone appear to have potential for POST control of mature goosegrass in bermudagrass, but seashore paspalum injury was unacceptable.
Nomenclature: Bermudagrass, Cynodon dactylon L.; goosegrass, Eleusine indica L.; seashore paspalum, Paspalum vaginatum Sw.