Residual Phytotoxicity of Fluometuron in Soils

Abstract

Initial and residual phytotoxicity of 3-( m -trifluoromethylphenyl)-1, 1-dimethylurea (fluometuron) in seven soils was studied under greenhouse condition, using oats ( Avena sativa L., var. Brave) as the bioassay species. The phytotoxicity of fluometuron in four of the soils, with an organic matter range of 1.0 to 5.0%, was not different at any one of the five cropping periods. Inactivation of fluometuron was more rapid in Eden silty clay loam with 3.3% organic matter than in Maury silty clay loam/silt loam with 7.2% organic matter. Phytotoxicity was significantly correlated with organic matter and soluble phosphorus during the first two cropping periods, and with cation exchange capacity, exchangeable calcium, total exchangeable bases, and soluble phosphorus during the last three croppings.