Preparation, characterization and antifungal activity of pyraclostrobin solid nanodispersion by self-emulsifying technique.

Background: Pathogenic fungi are the causal agents of 70-80% of plant diseases. Therefore, it is imperative to explore new and high effective fungicides. Constructing nanoscale fungicides using nanomaterial and nanotechnology has attracted wide attention in recent years.

Results: In this research, a pyraclostrobin solid nanodispersion (PSND) was prepared using the self-emulsifying method. The solid nanodispersion had a mean particle size of 20 nm and a zeta potential of -29.3 mV. The solubility and dissolution rate of the PSND increased owing to the decrease in particle size and the actions of the surfactants. The contact angle and retention volumes of the PSND on cucumber and cabbage leaf surfaces were greater than those of the commercial water dispersible granule. In addition, the median lethal concentration against Fusarium oxysporum was 0.7 43 µg mL . The toxicity of the nanoparticles was 4.5 times that of the water dispersible granule (WDG). The high fungicidal activity of PSND promoted the production of excess reactive oxygen species (ROS). The activity levels of the antioxidant enzymes containing superoxide dismutase (SOD) and catalase (CAT) decreased in F. oxysporum.

Conclusion: The research introduced a new method for preparing insoluble pyraclostrobin solid nanoformulation for fungicides to enhance the fungicidal activity and reduce environmental pollution. © 2019 Society of Chemical Industry.