Silicon via fertirrigation mitigates the effects of deficiency and toxicity of copper and zinc applied in soybean seed treatment

Abstract

To meet the requirement of micronutrients Zn and Cu in initial growth in soybean plants, seed treatment has been widely used, however, the supply of these elements in inadequate doses can induce toxicity. In this sense, the beneficial effects of silicon in mitigating abiotic stresses are well known, but little was studied in disorders induced by micronutrient toxicity, and there are no reports in soybean. Thus, it was aimed to evaluate whether Si application is efficient to alleviate stresses caused by Cu and Zn deficiency and toxicity on physiological and nutritional aspects in the initial growth of soybean crop. Two experiments will be conducted: Cu and Zn and the experimental design adopted will be in randomized blocks, in a 4x2 factorial scheme, being four concentrations of Cu (0; 0.18; 0.54 and 1.08 g/kg seed) and four concentrations of Zn (0; 0.40; 1.21 and 2.4 g/kg seed), and two concentrations of Si (0 and 2 mmol L-1), applied via fertigation. At 45 days the production of dry mass will be evaluated, as well as the number and dry mass of nodules per plant, the determination of total nitrogen (N) and crude protein (CP) content, the Si, Cu, and Zn content, the electrolyte leakage index, the concentration of photosynthetic pigments, the quantum efficiency of photosystem II, the content of total phenols and vitamin C. (AU)