Causes of phytotoxicity of metsulfuron-methyl bound residues in soil.
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.
Ye
Qingfu
Q
Institute of Nuclear-Agricultural Science, Hangzhou 310029, People's Republic of China.
Sun
Jinhe
J
Wu
Jianmin
J
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*
D001190:Arylsulfonates; D006540:Herbicides; D012989:Soil Pollutants; C050296:metsulfuron methyl