Biofortificação agronômica via aplicação foliar de selênio na cultura do alho nobre

Abstract

Selenium (Se) deficiency in soils and consequently in foods and human diets is a recurring problem in Brazil and various regions worldwide. Agronomic biofortification emerges as a sustainable alternative to mitigate this deficiency by promoting the enrichment of foods with essential micronutrients. This study aimed to evaluate the effectiveness of foliar application of sodium selenate in the biofortification of the noble garlic crop (Allium sativum L.), analyzing its impacts on crop yield, bulb quality, Se concentration, and the biochemical and physiological effects on the plants. The experiment was conducted in Lavras (MG), using a randomized block design in a 2 × 5 factorial scheme (two application period: 30 and 60 days after planting (DAP); and five Se doses: 0, 12.5, 25, 50, and 100 g ha-1 ). The foliar application of sodium selenate resulted in a linear increase in Se content, both in the shoot and in the bulbs, with greater efficiency being observed at the later period application (60 DAP). Plants treated with the highest Se dose (100 g ha−1) reached a Se content of up to 1.93 mg kg-1 in the bulbs, a value 52 times greater than the control treatment (0 Se), without causing phytotoxicity or compromising agronomic traits such as productivity, commercial classification, and dry matter. The simulation of daily Se intake through the average Brazilian garlic consumption (4.1 g day−1) indicated that biofortification at the highest Se dose would provide approximately 2.77 μg of Se per day, accounting for 5% of the recommended daily intake. Furthermore, when there was water restriction, selenium positively modulates the antioxidant system, reducing oxidative stress and increasing the activity of enzymes such as superoxide dismutase (SOD). It is concluded that the foliar application of sodium selenate is a viable and safe technique for biofortifying noble garlic, representing a promising strategy to increase the nutritional value of vegetables in regions with selenium-deficient soils, without compromising crop agronomic performance.