Eco-friendly synthesis of zinc oxide nanoparticles (ZnOnps) from Piper betel leaf extract: spectral characterization and its application on plant growth parameters in maize, fenugreek and red gram

Zinc oxide nano-particles (ZnONPs) were synthesized by the aqueous extract of the betel leaf and characterized by UV-visible spectroscopy, XRD analysis, Zeta potential and SEM studies. The ZnONPs had spherical to irregular shapes ranging from 45.8 to 68 nm with a zeta potential of -22.2 mV. The biogenic ZnONPs are used for plant growth properties in maize and fenugreek. The ZnONPs had more than two to three-fold increase in the plant root, height and yield in the plants. Further, the ZnONPs had no significant changes in levels of antioxidant enzymes in the treated plants but slightly reduced the biofertilizers in the plant rhizospheres and no significant changes in the nodulation of Rhizobium spp. Therefore, the biogenic ZnONPs synthesized exhibited excellent nano-fertilizers in non-nitrogen fixing (maize) and nitrogen-fixing plants (Fenugreek and Red Gram) with multiple modes of fertilization in soil and plants.