Intervention of Bacterial Leaf Spot of Bell Pepper through Neem Mediated Copper and Zinc Hybrid Nanoparticles

Bacterial leaf spot caused by Xanthomonas campestris pv. vesicatoria is a key pathological problem faced by bell pepper crop. The extensive use of chemical treatments has heightened environmental toxicity. Green-synthesized nanoparticles have been developed for managing plant diseases intervention while minimizing environmental harm. An experiment was carried out with three replications for each treatment, testing different concentrations (0.25%, 0.50%, 0.75%) of green-synthesized nanoparticles of Copper (Cu), Zinc (Zn), and a combination of Copper and Zinc (Cu+Zn) under laboratory conditions using a Complete Randomized Design (CRD) to manage Xanthomonas campestris pv. vesicatoria. The Cu+Zn nanoparticles exhibited the largest inhibition zone (13.733 mm), followed by Zn nanoparticles (7.9378 mm) and Cu nanoparticles (7.0048 mm), all compared to the control. Similarly, a greenhouse experiment with three replications of each treatment and concentration, which demonstrated significant results in lab conditions, was conducted. The Cu+Zn nanoparticles resulted in the lowest disease incidence (17.937 %), followed by Zn nanoparticles (22.966 %) and Cu nanoparticles (27.768 %), compared to the control. Additionally, a field trial was performed using a RCBD with three replicates per treatment and a single concentration that had shown the best results in lab conditions. In field conditions, Cu nanoparticles showed the highest disease incidence (31.374 %), followed by Zn nanoparticles (27.442 %) and Cu+Zn nanoparticles (22.637 %) in comparison to the control group. Recent outcomes suggest that neem-mediated copper-zinc hybrid nanoparticles are an effective tool for combating bacterial leaf spot in bell peppers.