Pesticide Residue Laboratory Department of Entomology, Tamil Nadu Agricultural University, Coimbatore, 641 003, India
Online published on 3 November, 2011.
Experiments were conducted to study the adsorption, desorption,movement, degradation and persistence of paraquat in different soils. The adsorption of paraquat in soils ranged from 57.9 to 94.6% with highest adsorption in peat soils, followed by laterite and black soils. The red and black soils desorbed more amounts of paraquat than the laterite and peat soils. The paraquat was retained in top soil, particularly in peat soils however, in laterite, black and red soils, paraquat moved up to 30 cm depth due to its high solubility. The highest persistence upto 160 days was seen in peat soils and the red soil registered the lowest persistence upto 90 days with half lives ranging between 15. 9 to 40.6 days.
Paraquat, adsorption, desorption, degradation, persistence
