Efficacy of a peracetic acid liquid formulation for controlling bacterial grain rot and bakanae disease and the underlying mechanisms

Abstract The peracetic acid (PAA) liquid formulation consists of 10% peracetic acid, 21% acetic acid, 17% hydrogen peroxide, and 52% water; these components are derived from food additives. Its broad antimicrobial spectrum and strong bactericidal effects make the PAA liquid formulation suitable for use as a seed disinfectant. In this study, PAA treatment methods and the efficacy of each component for controlling bacterial grain rot were evaluated. Soaking seeds for 24 h in a 100-fold diluted solution before seed treatments and soaking seeds in a 300-fold diluted solution prior to germination effectively controlled disease, with minimal phytotoxicity. Notably, hydrogen peroxide alone was ineffective. Acetic acid and a mixture of acetic acid and hydrogen peroxide were less effective than a mixture comprising peracetic acid and acetic acid. The study results revealed that the efficacy of treatments for controlling bacterial grain rot was due to peracetic acid. Additionally, treatment effects on bakanae disease were examined using the same methods. Treatments were effective for seeds with low disease incidence, but this efficacy was unstable when the disease incidence was high. Subsequently, the combined effects of treatment concentrations and durations were analyzed. Soaking seeds in a 100-fold diluted solution for 24 h the day before germination was highly effective, with minimal phytotoxicity. This treatment also high control efficacy against bacterial grain rot. However, application at advanced germination stages induce phytotoxicity.