Fomesafen and RE-40885 were compared to fluometuron in field experiments in 1986-87 at the Northeast Research Station near St. Joseph and the Dean Lee Research Station near Alexandria. Soil at the Northeast Station was Commerce silt loam with a pH of 6.0 and organic matter content of 1.0%. Soil at the Dean Lee Station was Norwood silty clay loam with a pH of 8.0 and organic matter content of 1.2%.

Fomesafen 0.38 lb/A was included in all experiments; however, other rates were evaluated in mst experiments. Fomesafen 0.38 lb/A was less effective in controlling of morningglory species, hemp sesbania, and smellmelon than fluometuron 1.2 lb/A preemergence surface (PES). Fomesafen 0.38 lb/A provided control of seedling johnsongrass, broadleaf signal grass and prickly sida equivalent to fluometuron 1.2 lb/A PES. Control of spotted spurge and purple nutsdedge was somewhat greater with fomesafen 0.38 lb/A compared to fluometuron 1.2 lb/A PES. Method of application (preplant incorporated or preemergence surface) had no consistent effect on fomesafen efficacy; however, in the one experiment where substantial cotton injury occurred (at the St. Joseph location), injury was greater in preplant incorporated treatments. Yield of fomesafen 0.38 lb/A treatments were consistently lower than those of fluometuron treatments.

RE-40885 0.75 lb/A was included in all experiments reported. Control of morningglory species, broadleaf signalgrass and hemp sesbania was less than that achieved with fluometuron 1.2 lb/A PES. Control of prickly sida was equivalent with RE-40885 0.75 lb/A and fluometuron 1.2 @/A PES. Severe injury occurred with RE-40885 treatments at the St. Joseph location both years. Preplant incorporation tended to enhance the activity of RE-40885 compared to preemergence surface treatments on seedling johnsongrass, but had little effect on its activity on other weeds or cotton. Yield of RE-40885 0.75 lb/A treated cotton was less than fluometuron treated cotton in all experiments.