Abstract: The tolerance of plants to hydric stress has become a global problem for sustainable agriculture. Nanotechnology is an emerging strategy designed to eliminate the awful effects of food shortage, heavy metal contamination and other abiotic stresses. Some studies show that iron oxide nanoparticles play a proficient role in stimulation of the growth, development, and enhancement of the stress tolerance of plants and the provision of nutrients. But there are studies that show the toxic effect of artificial nanoparticles on plants or ingested by animals. This study aims to provide new experimental data for clarifying the question of the positive or harmful impacts of magnetic iron oxide solution on plant growth in relationship with hydric stress. Our results have shown that the effect of iron oxide solutions on crop plants depends on how they are applied. In the case of ground application, there was a negative effect on the plant height and the leaf area meanwhile the sprays directly on the leaves (foliar application) had a positive effect on height of plants and leaf area. Under water stress conditions, the concentrated iron oxide solution had a negative effect on the leaf area, but dilute solutions had a positive effect on this trait. In both cases (ground and foliar applications), iron oxide treatments have diminished the negative effect of hydric stress. On the basis of these results it is highly recommended that the influence of low dose of iron nanoparticles (foliar applications) be used in order to stimulate seedling growth and increasing the water stress tolerance.
Keywords: maize, iron oxide nanoparticles, hydric stress, height of plants, leaf area, length of root, dry matter