AbstractOne of the most damaging pathogenic molds in peach fruits during warehousing period isRhizopus stoloniferthat significantly reduces storage time. Salicylic acid (SA) plays different crucial functions in plant tissues. In this study, the inhibitory effect of SA treatment on the growth ofR. stoloniferwas evaluatedin vitroandin vivo. The results obtained fromin vitroexperiments showed that SA significantly reducedRhizopusgrowth at all concentrations and, at 5 mM, the growth was completely inhibited.In vivoexperiments showed relatively high level of inhibition, though the postimmersion treatment as compared with the preimmersion treatment resulted in higher inhibitory effects. Regarding inhibitory effects of SA on controllingR. stolonifer, its application on peach fruits during postharvest period can be a promising strategy to control the growth and development of this fungus and enhancement of the warehousing time of the treated fruits.Practical ApplicationsRhizopus stoloniferwith serious and significant damages to agricultural products makes it essential to develop the effective control methods of this pathogen. Today, the use of synthetic chemicals for food preservation is largely abolished, because they can be hazardous for human and animal health. Therefore, there is a huge need for natural compounds with fungicidal attributes. The results of the current study illustrated the effective performance of salicylic acid (SA), one of the known phytohormones, for controllingR. stolonifergrowth in peach fruits. The application of immersion treatment inside SA solution can reduce the growth and development of the resulting diseases and also protect the fruits against the future damages of it. Furthermore, SA treatment can inhibit the growth of other pathogenic molds and reduce their injury to fruits.