In this study, the physicochemical properties of plasma‐activated water (PAW) prepared from air, , , and plasma and the trend of the concentration of reactive oxygen and nitrogen species (RONS) with respect to time were investigated and related to the effect of PAW on navel orange mold. The results showed that PAW had a strong lethal effect on navel orange mold and could effectively inhibit the mildewing activity of pathogenic spores. In addition, PAW is effective in reducing weight loss and decay of navel oranges during storage. This study suggests the potential application of PAW to prevent fungal infections during storage of agricultural products.