Field studies were conducted to evaluate foramsulfuron for postemergence control of goosegrass in bermudagrass turf as a possible replacement for MSMA. In field trials on a golf course and sports fields planted to bermudagrass, mature goosegrass was controlled effectively (>85% goosegrass dead on the basis of canopy area) with two applications of foramsulfuron plus metribuzin. The herbicide rates that were effective varied among studies, e.g., foramsulfuron at 0.029 or 0.044 kg ai/ha mixed with metribuzin at 0.105 to 0.210 kg ai/ha. Goosegrass was often controlled with MSMA at 2.24 kg ai/ha plus metribuzin at 0.105 to 0.210 kg/ha, but foramsulfuron was always as effective, or more effective, than MSMA, in controlling mature goosegrass, at the same rate of metribuzin. Bermudagrass phytotoxicity of foramsulfuron plus metribuzin was temporary and not different from MSMA plus metribuzin. In one location there was noticeable phytotoxicity 4 wk after initial treatment.

Dallisgrass response to various MSMA and foramsulfuron herbicide combinations was evaluated from 2004 through 2006 in North Carolina. Dallisgrass control declined with herbicide rates; therefore, only the highest rates (foramsulfuron, 0.15 kg ai/ha; MSMA, 2.5 kg ai/ha) are discussed. Foramsulfuron followed by (fb) foramsulfuron 1 wk after initial treatment (WAIT) provided 60% control of dallisgrass 1 mo after initial treatment (MAIT), but control declined to 40% 3 MAIT. MSMA (2.5 kg ai/ha) applied three times provided 89% dallisgrass control 1 MAIT, but control declined to 71% 3 MAIT. Among 22 MSMA and foramsulfuron sequential application programs, MSMA fb foramsulfuron 2 WAIT fb MSMA 3 WAIT provided the highest control (94%) of dallisgrass 1 MAIT, and control levels remained high (93%) 3 MAIT. This herbicide program provided 85% control 1 yr after initial treatment (YAIT), whereas no other treatment provided greater than 37% control 1 YAIT. Timing of foramsulfuron application following the initial MSMA application affected the control of dallisgrass. Waiting 2 WAIT, rather than 1 WAIT, before applying foramsulfuron increased control of dallisgrass by 20% 1 MAIT and 19% 3 MAIT. However, the increase in control 1 YAIT was only 5% regardless of herbicide rate. The addition of a second application of MSMA following the application of foramsulfuron 2 WAIT of MSMA further increased control by 10% 1 MAIT, 37% 3 MAIT, and 48% 1 YAIT. Results from this study suggest dallisgrass may be controlled with applications of MSMA fb foramsulfuron 2 WAIT fb MSMA 3 WAIT applied during early to midsummer. The use of MSMA was required to achieve dallisgrass control, however, the relatively high level of control achieved 1 YAIT with a program including sequential applications of MSMA and foramsulfuron may help reduce the total amount of arsenical herbicides used to control dallisgrass infestations over time.