Enhanced control of Botrytis cinerea via penthiopyrad-encapsulated biodegradable PLGA nanoparticles

Efficient pesticide utilization is essential for sustainable agriculture, as conventional applications suffer from low delivery efficiency and significant environmental losses. In this study, we developed a pesticide delivery system (PDS) based on biodegradable poly(lactic-co-glycolic acid) (PLGA) nanoparticles to enhance the antifungal efficacy of penthiopyrad against Botrytis cinerea , a representative filamentous plant pathogen. Penthiopyrad-encapsulated PLGA nanoparticles were prepared via a nanoprecipitation (poor solvent dilution) method, yielding particles with a median diameter of approximately 110 nm and high encapsulation efficiency. Confocal laser scanning microscopy revealed particle internalization into both hyphae and spores, indicating effective delivery to distinct fungal structures. Encapsulation increased particle number concentration, thereby enhancing contact probability with fungal cells and improving delivery efficiency. Biological assays demonstrated that, under the present experimental conditions, comparable efficacy was achieved at approximately 1% of the penthiopyrad concentration used in the commercial formulation. Thermodynamic analysis suggested favorable adhesion of PLGA nanoparticles to fungal cells and tomato leaf surfaces, potentially contributing to improved retention. These findings highlight the importance of particle size and interfacial interactions in pesticide delivery and provide a design principle for sustainable crop protection.