Persistence of metsulfuron-methyl in wheat crop and soil

Possible bioaccumulation of pesticides in crop produce may cause ailing effect on animal and human. Thus there is a need to evaluate these chemicals in the soil and crop produce at harvest. Metsulfuron-methyl is a post-emergence herbicide. It is highly active to control broad-leaf weeds in cererals, pasture and plantation crops. Metsulfuron-methyl was applied at 3, 4, 5, and 8 g a.i. ha(-1) rates, after 30 days of sowing in wheat as post-emergence herbicide. Soil samples treated with metsulfuron-methyl were collected after 30 and 60 days along with control and at harvest after herbicide application and analyzed for residues by High Performance Liquid Chromatography (HPLC) using photo diode array detector at 220 nm. Wheat grains and straw samples were sampled at harvest. At harvest the residue level of metsulfuron-methyl in soil was found below the detection limit at 3-5 g a.i. ha(-1) application rates and 0.002 microg g(-1) at 8 g a.i. ha(-1), respectively. No residues of metsulfuron-methyl were detected in wheat grains at 3-4 g a.i. ha(-1) rates. However 0.002 microg g(-1) residues were detected in wheat straw at 5 and 8 g a.i. ha(-1) application rates. It can be concluded that metsulfuron-methyl application at 3-4 g a.i. ha(-1) can be safely applied to the wheat crop as post-emergence herbicide.