Enhanced degradation of metalaxyl in Gley Humic and Dark Red Latosol

Abstract

SUMMARYEnhanced degradation of the fungicide metalaxyl was investigated in two soils: a gley humic (GH) and a Dark Red Latosol (LE), collected at sites never exposed to the fungicide. The soil samples were treated with successive applications of metalaxyl as a commercial formulation and 14 C-metalaxyl in laboratory. Metalaxyl biodegradation was analyzed during 63 days by means of radiometric techniques to verify biomineralization and degradation product formation from the applied 14 C-metalaxyl. Although biomineralization (maximum of 14 and 8% in the GH and LE soils, respectively), and partial degradation (about 32 and 48%, respectively) were detected in both soils, enhanced degradation was verified only in the GH soil. Results proved that metalaxyl behaves differently in soils.Index terms: degradation, fungicide, biomineralization. RESUMO: DEGRADAÇÃO ACELERADA DO METALAXIL EM SOLOS GLEI HÚMICO E LATOSSOLO VERMELHO-ESCURO A degradação acelerada do fungicida metalaxil foi pesquisada em dois tipos de solos: Glei Húmico (GH) e Latossolo Vermelho-Escuro (LE), coletados em regiões nunca antes expostas a este produto. As amostras dos solos foram tratadas em laboratório com aplicações sucessivas

Influence of repeated applications of glyphosate on its persistence and soil bioactivity

“…The 14 CO 2 quantification was performed by liquid scintillation counting (LSC) of 1.0 mL aliquots of the KOH solution of each flask (Papini & Andréa, 2000), after addition of Bray's scintillation solution modified by Mesquita & Rüegg (1984).…”

Comportamento Do Fungicida Metalaxil Em Solos Brasileiros Arenosos E Argilosos

“…Few studies on metalaxyl degradation, its transport in soils and plants have been performed in tropical soils and information on the behavior of this fungicide is limited (MUSUMECI & RUEGG, 1986;OSTIZ & MUSUMECI, 1989;PAPINI & ANDREA, 2000). The aim of this study was to gather information on metalaxyl degradation by studying the behavior of this fungicide in four Brazilian tropical soils.…”