Agronomic biofortification of sesame (Sesamum indicum L.) through zinc fertilization

Sesame (Sesamum indicum L.), which belongs to the Pedalaceae family, is one of the oldest and most widely used oilseed plants by humankind. The aim of this study was to evaluate zinc accumulation and physiological parameters in sesame plants submitted to agronomic biofortification through zinc fertilization management. The experiment was carried out in a randomized block design, with five treatments consisting of different levels of zinc (1.03; 2.06; 3.09; 4.12 and 5.15 mg dm-³) and four replications. The variables analyzed included zinc concentration in the plant organs, chlorophyll content, CO₂ concentration, stomatal conductance, transpiration rates and net CO₂ assimilation. The application of increasing doses of zinc promotes direct benefits in the production of photosynthetic pigments, especially chlorophyll “a”. Adequate doses of zinc increase photosynthetic efficiency, stomatal aperture and carbon assimilation. Among the organs of the sesame plants studied, the roots proved to be the main organ of zinc accumulation, while the grains benefited directly from this redistribution. These results confirm the effectiveness of the agronomic biofortification of sesame, especially the accumulation of zinc in the grains to improve their nutritional quality.