Synergistic effects of soil and foliar selenium application on growth, yield, and nutritional biofortification of okra (Abelmoschus esculentus L.) under open-field conditions.

Selenium (Se) is an essential trace element known to enhance plant growth, antioxidant metabolism, stress tolerance, and nutritional quality, making it an important component of sustainable agronomic biofortification strategies. The present study evaluated the synergistic effects of soil and foliar selenium application on the growth, yield, biochemical composition, and mineral enrichment of okra (Abelmoschus esculentus L.) under open-field conditions at the Sevoor farm of Vellore Institute of Technology. The experiment was conducted using a Randomized Block Design comprising seven treatments with three replications. Selenium was applied through soil and foliar methods at different concentrations, and growth, yield, biochemical, and mineral parameters were assessed. Significant treatment effects were observed (p ≤ 0.05). Among the treatments, combined soil and foliar application of selenium at 25 ppm (T5) showed significant effects, recording the highest plant height (139.92 cm), branches (30 plant-1), flowers (60 plant-1), pods (80 plant-1), and yield (760 g plant-1). Treatment T5 also significantly enhanced chlorophyll, carotenoids, carbohydrates, proteins, phenolics, flavonoids, antioxidant activity, and essential mineral accumulation compared to the untreated control. These findings demonstrate that optimized selenium treatments through integrated soil and foliar application can improve crop productivity, nutritional quality, and sustainability, supporting climate-resilient and nutritionally improved agricultural systems for future food security.