Laser-Fabricated Zinc Salicylate Nanoparticles as Dual-Functional Agents for the Suppression of Fusarium verticillioides and Growth Enhancement in Rice Seedlings.

Seed deterioration caused by Fusarium verticillioides severely limits rice productivity by impairing germination and seedling establishment. To develop an eco-sustainable alternative to synthetic fungicides, zinc (II)-salicylate nanoparticles (ZnSA NPs) with varying zinc-to-salicylate ratios-ZnSA-I (1:1), ZnSA-II (1:2), and ZnSA-III (1:3)-were synthesized via aqueous precipitation and further refined using blue laser ablation and probe sonication. Characterization by FTIR, UV-Vis, EDX, and TEM confirmed the formation of stable, uniform nanosized particles, with laser treatment reducing particle size and improving structural homogeneity. The optimized formulation, laser-engineered ZnSA-II (l-ZnSA-II), exhibited an average particle size of 8.99 nm, high colloidal stability with a zeta potential (-30.24 mV), and blue-shifted absorption spectra indicating quantum confinement. Antifungal assays showed strong inhibition of F. verticillioides with ED50 and ED90 values of 2314.66 and 3966.66 µg/mL, respectively. Nanopriming of infected rice seeds with l-ZnSA-II for 8 h reduced seed rot (16.5%) and seedling blight (10.5%), while enhancing germination (80%), shoot and root length (∼12 cm), seedling dry weight (0.51 g), and vigor index (40.96). The improved performance arises from enhanced zinc bioavailability and synergistic activity of zinc ions and salicylate ligands, positioning l-ZnSA-II as an eco-compatible nanopriming strategy for improving seed vigor and disease resistance in rice.