Suppression of Chlorothalonil Dissipation in Soil by Repeated Applications

Microbial Degradation of the Fungicide Chlorothalonil (Part 1)

Abstract

The dissipation of chlorothalonil (TPN, 2, 4, 5, 6-tetrachloro-1, 3-isophthalonitrile, Daconil^®, Dacosoil^®) in soils was suppressed by the repeated applications of this fungicide to the soils. The dissipation was due to microbial actions, since chlorothalonil disappeared in a nonsterile soil but not in an autoclaved soil. The amendments of the soil with easily decomposable organic materials recovered the suppressed dissipation ability of the soil. The results suggested that easily decomposable organic materials play an important role in the microbial degradation of chlorothalonil in soil.