Essential Oil of Xylopia frutescens Controls Rice Sheath Blight Without Harming the Beneficial Biocontrol Agent Trichoderma asperellum

Rice production experiences significant losses due to fungal diseases, particularly rice sheath blight caused by <i>Rhizoctonia solani</i>. Despite the intensive and continuous use of synthetic fungicides, diseases severity has not reduced and control has become increasingly challenging; therefore, the search for environmentally friendly and sustainable products has intensified. Here, we conducted a chemical characterization of <i>Xylopia frutescens</i> and using in silico analysis evaluated the interaction of their two major compounds with lectin protein site of <i>R. solani</i>. <i>In vitro</i> tests using increasing concentrations of essential oil against <i>R. solani</i> were performed. Subsequently, in four varieties of rice, five concentrations of <i>X. frutescens</i> essential oils were applied and evaluated the phytotoxicity effect as well the potential of <i>Xylopia frutescens</i> essential oil for controlling, both preventively and curatively, rice sheath blight. We further investigate the selectivity of this essential oil towards the non-target organism, <i>Trichoderma asperellum</i>. Our analysis revealed that trans-pinocarveol and myrtenal are the main compounds of <i>X. frutescens</i> essential oil and interact with the lectin of <i>R. solani</i>, supporting the antifungal properties of <i>X. frutescens</i> essential oil. In <i>in vitro</i> conditions, the highest tested concentrations of <i>X. frutescens</i> essential oil inhibited the pathogen's sclerotia and mycelial growth. Under greenhouse conditions, the treatments caused low phytotoxicity and effectively reduced disease severity when applied, both preventively and curatively. Furthermore, the biocontrol agent <i>T. asperellum</i> exhibited tolerance to <i>X. frutescens</i> essential oil. Collectively, our findings demonstrate the potential of <i>X. frutescens</i> essential oil for the development of botanical fungicides capable of controlling <i>R. solani</i> without harming beneficial non-target organisms such as <i>T. asperellum</i>.