Determination of imazethapyr residues in soil and grains after its application to soybeans

Imazethapyr is widely used in soybean, and leguminous crops for control of wide variety of broad leaf weed species. A study was conducted to evaluate residues of imazethapyr in the soil and soybean grain at five different locations in India. Imazethapyr was applied at 100 g/ha, as a post emergence herbicide to control weeds in soybean fields. Residues of imazethapyr were found in the range from 0.006 to 0.018 µg/g in the soybean grains samples in all five locations. However in the soil, residues were found to be below 0.0010 µg/g in four locations, and 0.0015 µg/g in one location. Less residues were found in soils as compared to plant samples. Based on this study a pre-harvest interval of 90–102 days is suggested for soybean crops after imazethapyr application. This indicates the judicious use of imazethapyr by farmers in soybean fields.