Development and characterization of florasulam nanosuspension for efficient weeds control: inhibition of Ostwald ripening, improved interfacial properties, and enhanced field herbicidal activity

BACKGROUND Nanosuspensions possess advantages such as a high surface area to volume ratio, scalable preparation and improved biological activity. However, the increase in particle size during processing and storage hinders their development for industrialization and large‐scale application in sustainable agriculture. Herein, a florasulam nanosuspension (NS) was successfully prepared by screening dispersants using the wet media milling technique, and the mechanism of particle size increase and regulatory strategies were identified. RESULTS The results showed that the mechanism of particle size increase in NS was Ostwald ripening rather than coalescence. Because of the pH‐dependent water solubility of florasulam, solubility can be decreased by regulating the pH of the dispersion system to 4, which further decreased the Ostwald ripening rate by 39.2%. NS exhibited excellent colloidal stability, and the Turbiscan Stability Index (TSI) was 0.47; the TSI of the commercial formulation (SC) was 18.58. Compared with SC, the droplet spreading diameter of NS increased by 4.89% to 11.15%, the equilibrium contact angle of NS decreased by 15.17° to 19.33°, and the adhesive force of NS increased by 5.79% to 8.63%. Furthermore, penetration of florasulam in NS on the surface of weed leaves increased by 30.55% compared with SC after 48 h. Moreover, the fresh weight control effect of NS against broadleaf weeds was increased by 16.04% to 41.31% in wheat fields compared with SC. CONCLUSIONS These findings provide a simple and achievable strategy for constructing stable and eco‐friendly herbicide nanosuspensions and support the efficient and economical management of weeds in wheat fields.