Herbicide Control of Dallisgrass In Bermudagrass Turf.

Dallisgrass has proved to be a problematic weed species in many turf applications.   This study was conducted to determine control effectiveness of new sulfonylurea herbicides (Revolver^™ and Monument^®) in comparison to the standard treatment of MSMA.   Bermudagrass phytotoxicity was also evaluated for each of these herbicides.   This study was conducted at Raven Nest Golf Course in Huntsville, Texas.   A randomized complete block design was used to test MSMA, Revolver^™, MSMA+Revolver^™ and Monument^® treatments.   Herbicides were applied by broadcast spraying at labeled rates and frequencies.   The only treatments showing acceptable control (≥90%) were the MSMA and MSMA+Revolver^™ treatments.   However, the control achieved was short lived, lasting about 8 weeks after initial treatment (WAIT).   Treatments including MSMA were the only ones causing bermudagrass phytotoxicity at 1 WAIT.   However, by 2 WAIT bermudagrass made a full recovery.   In conclusion, the sulfonylurea herbicides tested in this study did not prove to be an acceptable substitute for MSMA in providing dallisgrass control in bermudagrass turf.

KEY WORDS: Dallisgrass control, Paspalum dilatatum, Bermudagrass, Cynodon dactylon, Phytotoxicity, MSMA, Foramsulfuron, Trifloxysulfuron-sodium.