The Effects of Green-synthesized Silver Nanoparticles (AgNPs) on Seed Germination and Growth of Maize (Zea mays L.) Under Drought Stress

Nano priming has shown considerable potential for improving crop performance under water stress conditions. This study aimed to evaluate the effects of silver nanoparticles (AgNPs) on seed germination, growth, and physiological responses of maize (Zea mays L.) under drought stress. The experiment was conducted between January and November 2024 at the Department of Plant Science and Biotechnology, Bayero University, Kano, Nigeria. Silver nano particles were synthesized from Moringa oleifera and characterized using green technology. A laboratory germination experiment and a screenhouse pot experiment were conducted using a completely randomized design with three replications. Seeds of three maize varieties (SAMMAZ 27, SAMMAZ 51, and a local variety) were primed with AgNPs at 0, 20, 40, 60, and 80 mg/L for 24 hours. Drought stress was imposed in the screenhouse by withholding water for 14 days at 21 days after germination. AgNP priming had no significant effect on germination percentage across treatments. However, under drought stress, 40 and 60 mg/L AgNP treatments reduced drought-induced growth inhibition, resulting in 40.9% improvement in plant height and 1.2% increase in moisture content. Leaf area increased by 30.8% in SAMMAZ 27, while at 20 mg/L, shoot–root ratio, chlorophyll content, and relative water content increased by 46.6%, 21.34%, and 10.5%, respectively, with clear genotype-specific responses. Antioxidant activity was enhanced, as evidenced by increased superoxide dismutase (SOD) and catalase (CAT) activities in SAMMAZ 27 and the local variety. In conclusion, the research demonstrated the potency of AgNPs in enhancing maize germination under drought stress through initiation of pre- germination metabolic activity and also increases the morphological and physiological drought attribute of maize plant.