PERSISTENCE AND LEACHING OF AMETRYNE IN SOIL WITH SUGAR-CANE CROP

The persistence and the leaching of ametryne was investigated under field conditions in Campinas, SP, in a loamy podzolred-yellowsoilplantedwithsugar-canecrop. Theametrynewasappliedattherateof4.0kg/haaftersugarcane planting and pre emergence of weeds in 1992 April seventh. Gas chromatography analyses of soil samples collected at five depths (0-10cm, 10-20 cm, 20-30 cm, 30-40 cm and 40-50 cm) eighttimes at after the herbicide application over a year showed that the greatest ametryne concentration stayed at the 0-10 cm layer; ametryne residues were not found under 30 cm of soil depth and the persistence curve of the herbicide was accounted for by 2nd grade regression. A year after the treatment no ametryne residues were found in the soil.

KEY WORDS:
Residues; herbicides; movement; ecotoxicology; ametryne.