Response of Maize To Foliar Spraying of Ag2O and Co3O4 Nanoparticles: Biometric and Nutritional Parameters

This study evaluated the effects of foliar spraying of conventional sources and nanoparticles (NPs) of silver (Ag) and cobalt (Co) on biometric parameters and nutrient contents in the shoot dry biomass of maize. Methods: The experiment was conducted in a completely randomized design with four replications. Treatments comprised four concentrations (0, 50, 100, and 200 mg L− 1) and three sources of Ag and Co. Root length and dry weight, shoot length and dry weight, SPAD index, and the contents of phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn) in shoot dry biomass were determined. Results: Foliar application of Ag2O NPs increased root length, whereas foliar treatment with Co3O4 NPs enhanced root and shoot dry weights. Both NPs increased SPAD index at the lowest concentrations. Ag2O NPs reduced P, K, Ca, and Zn and increased Mg, Fe, Cu, and Mn contents in shoot dry biomass. Co3O4 NPs increased Ca and Mg and decreased K and Fe contents in shoot dry biomass. Conclusions: Ag2O and Co3O4 NPs altered maize growth and nutrient uptake.