Persistence of ametryne, atrazine, simazine and diuron in soil, after repeated annual applications in sugar cane culture

Abstract

The soil persistence of ametryne, atrazine, simazine and diuron (2.8 kg/ha of each product), was investigated. They were applied in the month of September, during three years, under field conditions of day soil sugar-cane crop at Limeira, SP, Brazil. Analyses of soil samples, collected at 0 cm to 10cm and 10 cm to 30 cm depth, 30, 60, 90, 120, 150 and 160 days after the herbicide applications showed through oat bioassays in phytotron conditions that at 0 cm to 10 cm of depth the soil did not present residual bioactivity of ametryne, 90 days after its application; for atrazine, simazine and diuron, this phenomenon happened after 60 days. Soil samples of 10 cm to 30 cm of depth did not show presence of herbicides.