Persistence of oxyfluorfen in soils under different soil moisture regimes

Persistence is an important characteristic of herbicide affecting efficacy and carryover to subsequent crops. The period during which the pesticide remained intact and biologically active has great practical importance in determining how well it performs its intended task in soil. It is also called as time of residence of chemical in soil and is measured in terms of half life. A field study was conducted to determine persistence of oxyfluorfen residue in different soils under different soil moisture regime. Under the influence of moisture regimes higher persistence of oxyfluorfen was observed in Chamarajanagar soil followed by Shimoga and Mandya soils. Increased degradation of oxyfluorfen was observed with increased moisture content from 50 per cent soil moisture status, maximum water holding capacity to submergence. Half life found to be increased with decreased moisture and was in the order of 50 per cent maximum water holding capacity > maximum water holding capacity > submergence.