title: Causes of phytotoxicity of metsulfuron-methyl bound residues in soil.
abstract: The bioavailability and phytotoxicity of bound residues of metsulfuron-methyl were studied using 14C-labeling and bioassay with oil rape (Brassica napus L.). Soil bound residues at the concentration of 0.27 and 0.53 nmol g(-1) resulted in significant inhibition of oil rape seedling growth. The biologically active component of the bound residues was identified to be metsulfuron-methyl parent compound. Other metabolites, including the hydrolysis product 2-methylformate-benzenesulfonamide, showed no toxicity to the test species. This study suggests that residues of metsulfuron-methyl bound previously to the soil matrix could be again released upon planting. The phytotoxicity of metsulfuron-methyl bound residues was mainly caused by the metsulfuron-methyl parent compound that became available during plant growth.
authors.affiliation: Institute of Nuclear-Agricultural Science, Hangzhou 310029, People's Republic of China.
authors.forename: Qingfu
authors.initials: Q
authors.lastname: Ye
authors.forename: Jinhe
authors.initials: J
authors.lastname: Sun
authors.forename: Jianmin
authors.initials: J
authors.lastname: Wu
mesh_terms: D001190:Arylsulfonates / Q000633:toxicity*; D001673:Biodegradation, Environmental; D001937:Brassica / Q000187:drug effects* / Q000254:growth & development; D004784:Environmental Monitoring / Q000379:methods*; D006540:Herbicides / Q000633:toxicity*; D012989:Soil Pollutants / Q000633:toxicity*
chemical_list: D001190:Arylsulfonates; D006540:Herbicides; D012989:Soil Pollutants; C050296:metsulfuron methyl