Persistence of butachlor in sandy clay loam soil and its residues in rice grains and straw

The residue level of butachlor in soil was found 0.635 μg g⁻¹ 24 hrs after butachlor application, which decreased to 0.032 μg g⁻¹ at harvest. Rice grain and straw samples contained 0.029 μg⁻¹ and 0.042 μg g⁻¹ residues. The dissipation of butachlor under field and laboratory conditions was compared. Half-life of butachlor was found to be 18.11 days under field conditions at 1.0 kg ha⁻¹ and 20.2 and 23.0 days at 1.0 kg ha-1 and 2.0 kg ha-1, respectively under laboratory condition. Rapid dissipation of butachlor was found under field as compared to laboratory conditions.