Dynamics of herbicide degradation in cauliflower

Abstract

The aim of this work was to compare the dynamics of the degradation of herbicides commonly used in brassica vegetables. Series of plot field experiments were carried out in planting cauliflower in 2012–2014. The amount of herbicide residues with the maximum residue level (MRL) determined by the Regulation (EC) No. 396/2005 and with requirements of non-residue production (up to 10 µg/kg of active ingredient in harvested product) was compared. Napropamide, clomazone and dimethachlor were applied before planting and pendimethalin, S-metolachlor, pyridate, ethametsulfuron, dimethenamid, metazachlor, quinmerac, picloram, clopyralid, cycloxydim, fluazifop, propaquizafop and quizalofop were applied after planting the cauliflower. Besides fluazifop and quizalofop, all tested herbicides showed a fast degradation and can be recommended for non-residue production. The amount of fluazifop residues did not fall below the MRL even 6 weeks after application. Residues of post-emergently applied quizalofop were detected in cauliflower 10–44 days after application in most of the samples at concentration 9–73 µg/kg(below the MRL).