2017 ASHS Annual Conference

High quality seed is the critical aspect in onion (Allium Cepa L.) production. Nano-priming is an innovative technique for improving seed germination and initial growth. Due to higher surface to volume ratio, small sizes and increased reactivity, nanoparticles penetrate into the pores of seeds, spread inside, and activate phytohormones that stimulate physiological growth. In this study, phytochemicals extracted from agro-industrial byproducts were used for synthesis of nanoparticles in place of highly toxic inorganic reducing agents, which pose risks for environmental and human health hazards. Green nanoparticles were prepared by a dropwise reduction method and characterized using ultraviolet-visible (UV-Vis) spectroscopy and dynamic light scattering (DLS) techniques. Silver nanoparticles (AgNPs), gold nanoparticles (AuNPs) and nanoemulsions prepared using turmeric and citrus oil were formulated and used for priming onion seeds for 12 hrs. Dry and hydroprimed seeds were used as controls. Seeds were planted in the greenhouse and germination percentage (GP) was recorded, 6 and 21 days after sowing (DAS). GP was found to be 47% and 19% higher in AuNPs treatment at 6 and 21 DAS respectively, as compared to controls. Different growth and yield parameters were assessed in the field at College Station, Texas after transplanting. Results demonstrated that nanopriming had significant effects on shoot length, number of leaves per plant, leaf surface area and bulb diameter. Quality parameters were evaluated after harvesting of onions. Pyruvate levels were found to be lower in AuNps treated bulbs. Total phenolics in bulb and chlorophyll content in leaves were superior in nano treated plants as compared to controls. Results indicate that nanopriming has a significant impact in seed germination, growth and quality of onion.