Metsulfuron in Surface Groundwater of a North Florida Flatwoods

Abstract

A 4 ha Florida flatwcods pine site was monitored for surface groundwater contamination following application of 0.084 kg ai/ha (1.2 oz metsulfuron/ac) in 140 liters of water carrier per hectare. Treatment was applied in November 1989. An HPIC analytical prccedure is presentedwhich has a detection limit of 1 mg m^-3 (1 ppb). A total of 24 shallow groundwater wells were used to monitor for surficial water table contamination, and surface water contamination was monitored in runoff and from water collected from surface depressions. One well sample of 207 collected in the 2 month period between application and 5 January 1990 contained detectable metsulfuron (2.3 mq m^-3). IWO surface depression water samples collected December 9 and 13, 1989 contained 8 mg m^-3 of metsulfuron. other samples did not contain detectable amounts of metsulfuron. Lightning strikes disabled the automatic water sampler during the first major storm after application preventing collection of runoff samples . Because the first runoff producing storm occurred at about the second hydrolytic half-life for this herbicide, it is unlikely significant amounts moved off site in storm runoff. The results are similar to those reported for sulfometuron on similar sites.

Citation

Michael, J.L.; Neary, D.G.; Fischer, J.; Gibbs, H. 1991. Metsulfuron in Surface Groundwater of a North Florida Flatwoods. In: Proceedings Southern Wed Science Society Perception: Fact or Fiction 44th Annual meeting. 1991 January 14-16; San Antonio, TX. [Champaign, IL]: Southern Weed Science Society. 233-237