Vol. 9, Issue 1, Part H (2025)

The green synthesis of nanoparticles has garnered significant attention in recent years. This study focused on synthesizing and characterizing silver (AgNPs) and zinc (ZnNPs) nanoparticles using guava (Psidium guajava) leaf extract via reduction method. The study, conducted at the Green Nano-Technology Laboratory, University of Agricultural Sciences, Dharwad, during 2023-24, employed a Completely Randomized Design (CRD) with three replications. The bio-reduction of 1 mM silver nitrate and 1 mM zinc sulphate using guava leaf extract resulted in a colour change from pale brown to crimson brown for AgNPs, and brown to light yellow for ZnNPs, confirming nanoparticle formation. Characterization through UV-Vis, PSA and SEM revealed absorption peaks at 430 nm for AgNPs and 250 nm for ZnNPs, with average particle sizes of 36.79 nm and 28.17 nm, respectively. SEM images showed hexagonal and irregular crystal structures for AgNPs and ZnNPs. The synthesized nanoparticles were evaluated for seed priming in Red sander seeds using different concentrations (500, 1000, 1500 and 2000 ppm) and durations (12 and 24 hours). ZnNPs priming at 2000 ppm for 24 hours resulted in the best seed quality, showing significant improvements in seed germination, root length, shoot length and Seedling Vigor Index-I.