Suppression of chlorothalonil degradation in soil after repeated application

✍ Scribed by Kei Motonaga; Kazuhiro Takagi; Satoshi Matumoto

• Book ID: 102197889
• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 64 KB
• Volume: 17
• Category: Article
• ISSN: 0730-7268
• DOI: 10.1002/etc.5620170806

✦ Synopsis

Mechanisms of degradation suppression of chlorothalonil after repeated application were investigated. Under laboratory conditions, soil was treated sequentially with 40 mg/kg dry weight of chlorothalonil. This resulted in the degradation suppression of chlorothalonil and accumulation of the metabolite 4-hydroxy-2,5,6-trichloroisophthalonitrile (TPN-OH) in soil. After pretreatment with three kinds of chlorothalonil metabolite, only TPN-OH was found to suppress chlorothalonil degradation in soil. After the pretreatment of TPN-OH, residual chlorothalonil in soil at 1 week after application was 9 to 11% higher than those with pretreatment with other metabolites and control. The TPN-OH pretreatment also suppressed soil respiration and TPN-OH was more persistent in soil than chlorothalonil, indicating that toxicity of residual TPN-OH may suppress the degradation of chlorothalonil in soil.