In the present study, green synthesis of zinc oxide nanoparticles (ZnO NP) using (leaf litter) extract was explored after characterization with UV spectrophotometery, Fourier Transform Infrared analysis, X-ray diffraction and TEM studies. ZnO NPs stability was ensured with - 32.1 mV zeta potential, while TEM showed ZnO NP as hexagonal structure (100 nm). In vitro antimicrobial activity showed potential of ZnO NP against pathogens causing diseases in maize plants. Both in vitro and in vivo studies of ZnO NP and ZnSO (200 ppm and 400 ppm) over a two year period (2019, 2020) were conducted on L. var. PG2458. ZnO NP seed priming improved seed vigor index, germination percentage, shoot and root length and fresh biomass. Foliar application improved stem diameter and leaf surface area. Physiological status was relatively better, while reproductive attributes got altered to guide resource allocation for better cob growth and biomass with ZnO NP. Leaf, cob, grain and total Zn was maximum for 200 ppm ZnO NP. Translocation of Zn from leaf to cob and cob to grain was faster for ZnO NP compared to ZnSO. Higher concentration (400 ppm) of ZnO NPs and ZnSO proved phytotoxic for plant growth attributes. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-022-01136-0.
