Evaluating the efficacy of plant-mediated copper-silver nanoparticles for controlling Cercospora leaf spot in mung beans

Cercospora leaf spot (CLS), caused by Cercospora canescens, is a highly destructive disease of mung beans, capable of causing up to 95% yield losses under favorable environmental conditions. Plant-mediated nanoparticles (NPs) have gained significant attention in plant disease management due to their unique properties and potential benefits. This study aimed to evaluate the antifungal efficacy of green-synthesized copper (Cu) and silver (Ag) nanoparticles, both individually and in combination, against C. canescens. The nanoparticles were tested at different concentrations (0.25%, 0.50%, and 0.75%) using the poisoned food technique under laboratory conditions. The most effective concentrations were further assessed under field conditions. In the laboratory, the combination of Cu and Ag nanoparticles showed the least mycelial growth (13.29 mm), followed by Ag nanoparticles (18.18 mm) and Cu nanoparticles (22.22 mm), compared to the untreated control. Similarly, under field conditions, the combination of Cu and Ag nanoparticles resulted in the lowest disease incidence (22.45%), followed by Ag (29.94%) and Cu nanoparticles (36.50%). These findings suggest that hybrid Cu-Ag nanoparticles have significant potential as an effective tool for managing CLS in mung beans, offering a sustainable alternative for disease control.