Will Hexazinone Work for Brunswickgrass Management?
by Brent Sellers, Professor and Associate Center Director, Pasture and Rangeland Weed Management
UF/IFAS Range Cattle Research and Education Center
Brunswickgrass or brown-seed paspalum is a warm-season perennial grass that is native to South America. It was introduced as a potential species to reduce soil erosion as well as forage for grazing. It is adapted to a variety of soil types, and will grow in acidic soils. Some evidence suggests that Brunswickgrass has been in Florida since the 1960s.
Recently, Brunswickgrass has been determined to be a contaminant of ‘Pensacola’ bahiagrass seed production fields. Due to the presence of Brunswickgrass seed, other states in the southeast have begun to limit sales of Florida-grown bahiagrass seed due to contamination with this unwanted species. While the bulk of infestations appear to be in north-central Florida, Brunswickgrass has been identified in pastures in south-central Florida. Therefore, it is likely that this grass species is more widespread than initially thought, and determining how wide spread Brunswickgrass is in the state will likely be proportional to the number of people of learn to identify Brunswickgrass.
In our January Ona Highlight, https://www.youtube.com/watch?v=3975TSyihis, Brunswickgrass identification and management is discussed. Identification characteristics can also be found the EDIS fact sheet (http://edis.ifas.ufl.edu/ag408). Management of Brunswickgrass will likely involve an application of hexazinone. While we have good evidence that this will work very well for controlling Brunswickgrass, a lot of questions remain including the correct application timing, how long seeds are viable in the soil, and the number of annual applications needed to limit seed contamination. In addition to herbicide work, crop rotation is also under investigation. Data show that annual grass rotations are better at preventing Brunswickgrass reestablishment than annual broadleaf rotations. Stay tuned. Research on Brunswickgrass management will continue.