Persistence of Fluazifop-p-butyl in an Inceptisol

The persistence of fluazifop-p-butyl at two rates of application and at three temperatures in a sandy loam soil was studied. The herbicide was found to be readily lost as only 2% fluazifop-p-butyl was recovered after 24 h. Persistence studies were based on transformed fluazifop-p-acid from fluazifop-p-butyl and reported as total residues. The acid form of the herbicide had a half life of 19.8 days at normal and 23.9 days at double the rate of application Persistence was inversely related to soil temperature as 2.5 and 6% higher dissipation of fluazifop-p-acid occurred at 40 ± 1°C compared to 35+1° or 28±1°C Fluazifop-p-butyl was degraded in soil to corresponding acid, fluazifop-p, which is also known to be herbicidally active.