Persistence of herbicides in clay soil under sugarcane crop

Abstract

The persistence of simazine (2.80 kg/ha), ametryne (2.8 kg/ha), atrazine (2.8 kg/ha), diuron 2.8 kg/ha) and tebuthiuron (1.2 kg/ha), applied in April in a clay soil planted with sugarcane was investigated for two consecutive years under field conditions at Capivari SP, Brazil. Out bioassays conducted under phytotron conditions indicated that the order of persistence is: tebuthiuron > diuron > simazine > atrazine > ametryne. Tebuthiuron did not present residual bioactivity after 14 months from its application; diuron and simazine after 11 months; atrazine and ametryne after 7 months, were no longer found in the soil (0 to 10 cm depth).