The magnesium oxide nanoparticles (MgO NPs) were synthesized using aqueous leaf extracts of (Betel) by bio combustion method. The synthesized magnesium oxide nanoparticles were characterized by XRD, FTIR, TG/DTA, PSA and SEM. The seeds treated with synthesized MgO NPs showed better germination but the seedling growth of tested species was affected when exposed to concentrations of MgO NPs. In this experiment mainly focused physical characteristics of the maize plants like, germination percentage (GP), germination index (GI), vigor seedling index (VSI), relative seed germination (RSG), relative root growth (RRG), Biomass, Root length and shoot length. Magnesium oxide nanoparticles may hold significant applications in agriculture and gardening by selectively inhibiting harmful fungi and bacteria presents on seeds and could provide as an alternative source of fertilizer that may improve sustainable agriculture. The chlorophyll test was carryout after 20 days maize plants, the low concentration MgO NPs treated maize plant shown chlorophyll content increase when compare to other treatments and control.