Preparation and Synergistic Effect of Composite Solid Nanodispersions for Co-Delivery of Prochloraz and Azoxystrobin

Abstract

The low efficacy of traditional single-component pesticide formulations has resulted in excessive pesticide application, the evolution of pest resistance, and a range of food safety and environmental concerns. Developing efficient composite nanopesticides represents a critical strategy for addressing the above challenges. In this study, solid nanodispersions (SNDs) co-loaded with prochloraz and azoxystrobin were constructed through a self-emulsifying carrier adsorption method. The antifungal activities of the composite SND with a 14:1 ratio of prochloraz to azoxystrobin against Fusarium graminearum and Pyricularia oryzae were 2.3-fold and 1.6-fold higher than those of commercial microemulsions (MEs) with the same proportion of active ingredients. The SND could cause severe oxidative damage to fungi, by reducing the activities of superoxide dismutase (SOD) and catalase (CAT), and break the permeability of cell membranes, resulting in fungal death. Additionally, the composite SND exhibited superior foliar wettability and biosafety with a minimal environmental cost, thereby enhancing the pesticide’s effective utilization rate. This research provides theoretical and technical support for the design and development of high-efficiency composite nano-fungicide, holding promise for sustainable disease management.