Comparative soil and plant metabolism of carbosulfan, furathiocarb and carbofuran in Brussels sprouts, cauliflower and sugar beet crops

Abstract

Brussels sprouts and cauliflower crops were soil treated at planting by one of the insecticides carbosulfan, furathiocarb, or carbofuran; moreover, a sugar beet crop was soil treated by carbofuran applied in the sowing furrow. In the soil, carbosulfan and furathiocarb were transformed into carbofuran, which then was transformed mainly into 3‐ketocarbofuran, carbofuran phenol, and 3‐ketocarbofuran phenol. In the soil of the carbosulfan treated crop, the carbosulfan and carbofuran concentrations were similar. In the carbosulfan treated soil, the concentrations of the sum carbosulfan‐+ carbofuran were higher than the carbofuran concentrations in the carbofuran treated soil. The chemical derivatization of the carbamate function which occurs in carbosulfan thus slowed down its soil biodegradation relative to the non derivatized carbamate function in carbofuran. The same occurred with furathiocarb, but with a lower intensity. When the soil microbial activity was exceptionally enhanced (by the climate and by a l...