Morphophysiological Changes Resulting from the Application of Silicon in Corn Plants Under Water Stress

Silicon (Si) is a beneficial element for plants, the accumulation of which in plant cell walls prevents water loss through transpiration, which may represent an adaptive strategy for coping with drought stress. Future climate change scenarios predict that drought will become an increasingly important stress factor affecting crop productivity. This problem will be exacerbated by the tendency to irrigate crops with excessive amounts of water, a practice that is both environmentally and economically unsustainable. In this study, we aimed to evaluate the agronomic, physiological, and metabolic aspects of Si translocation in corn crops subjected to drought conditions and excess irrigation. The study was organized in a completely randomized factorial scheme, with five concentrations of applied Si and five levels of irrigation. The findings of the study indicated that the application of Si increased plant growth, stomatal density, and bulliform cell diameter, which provide a better balance in water use and photosynthesis, thereby favoring greater Si translocation and, consequently, an increase in the grain production of corn plants. Furthermore, we found that the application of water to the soil equivalent to 130% and 160% of the recommended level (excess water stress) does not increase plant metabolism or grain production, but does increase water consumption and production costs.