Foliar iron and zinc nano-fertilizers enhance growth, mineral uptake, and antioxidant defense in date palm (Phoenix dactylifera L.) seedlings

Abstract Salty sandy soil usually hinders plant growth, while spraying nano-fertilizers such as iron and zinc enhances plant growth. This experiment investigated the role of iron and zinc nano-fertilizers (1 g l–1) in the adaptation of date palm seedlings (cv. Barhee) subjected to salt stress (0, 75, 150 mM NaCl). Nano-fertilizer increased plant height, length of roots, number of leaves, and roots. In contrast, salt stress led to reducing these parameters. Salt stress increased hydrogen peroxide, electrolyte leakage, malondialdehyde, and antioxidants such as soluble proteins, proline, catalase, ascorbate peroxidase, and peroxidase enzyme in the leaves. Abscisic acid also increased. Nano-fertilizers increased the chlorophyll and dry matter of the plant under salt stress. Nano-iron induced better seedling growth than nano-zinc, especially in the length of the roots. Nano-iron under salt stress increased iron and potassium concentration and K/Na ratio in leaves. Nano-fertilizers help the plant adapt to environmental stresses, and seedlings succeed in growing in saline sandy soils.