FIELD PERSISTENCE OF BIOAVAILABLE FLUMETSULAM

Field research was conducted in 1994 and 1995 to monitor the dissipati on of flumetsulam in five Mississippi soils for a period of 16 wk. The se soils allowed evaluation of flumetsulam persistence across three so il series with a relatively constant soil pH of 6.0, as well as across three soils of varied pH from 6.0 to 7.6 within a constant soil serie s. Bioavailability was determined with a rice root length bioassay. Pr edicted half-lives ranged from 20 to 26 d in 1994 and from 23 to 46 d in 1995. Persistence decreased with increasing cumulative rainfall and decreasing organic matter content (within a range of 1.2 to 3.5%). So il pH had no measurable effect on flumetsulam persistence.