Fe2+ and Mn2+, potential agents to induce suppression of Fusarium oxysporum for biological soil disinfestation

Here Fusarium oxysporum was killed in exudates obtained from soil biologically disinfested with ethanol, indicating that physical interaction with soil microorganisms was not essential. Because acetic acid was confirmed to accumulated during the treatment, we evaluated the effect of acetic acid amendment against the pathogen in plastic containers. A drop in the soil redox potential seemed to be correlated with the fungicidal efficacy of acetic acid. Under reductive soil conditions, metal ions such as Mn²⁺ and Fe²⁺ formed, and the pathogen was effectively suppressed in Mn²⁺ and Fe²⁺ solution. Therefore, Fe²⁺ and Mn²⁺ may be the agents that induce suppression of the pathogen during biological soil disinfestation.