Fertilizer formulation alternatives that avoid unnecessary losses and environmental impacts are being investigated in agricultural management. Seed priming with nanofertilizers prior to planting, reduces concerns about non-target dispersion; however, priming formulations and concentrations must be carefully selected to avoid undesired effects. Here, seed germination and seedling development were evaluated after seed priming with CuO nanoparticles (NPs), CuO bulk and CuCl2. The seeds were immersed in priming solutions of 0, 20, 40, 80 and 160 mg.L−1 Cu for the three Cu sources. Following 8 hours priming, the seeds were evaluated for germination and vigor (first germination count). Root and shoot lengths were measured as well as shoot and root dry biomass. The copper NP did not show any toxic effects on corn seed germination and growth, and also promoted higher biomass when compared to the other Cu sources. On the other hand, CuCl2 primed seeds exhibited Cu-toxicity in roots and shoots for all concentrations tested. Bulk Cu priming results indicated the better role of NPs size effects. These findings support NP-seed priming as an alternative to delivery of essential micronutrients, such as copper, to corn seedlings.
nanofertilizer; phytotoxicity; characterization; X-ray diffraction; transmission electron microscopy