Aplicação foliar de zinco: efeitos sob a biofortificação agronômica da mandioca cultivada em condições de cerrado

Abstract

Zinc (Zn) deficiency is a global public health concern, and agronomic biofortification has emerged as a promising strategy to increase micronutrient content in staple crops. This study evaluated the effect of foliar Zn application (600 g ha⁻¹) on physiological performance, Zn concentration in roots, starch content, and yield of 20 cassava genotypes (Manihot esculenta Crantz). The experiment was conducted at the experimental unit of the Instituto Federal de Mato Grosso do Sul, Nova Andradina, over two growing seasons under field conditions from 2022 to 2024, using a randomized complete block design (RCBD) with and without foliar fertilization with Zn. Foliar Zn significantly increased physiological evaluations, showing average increases of 40% in net photosynthesis, 120% in stomatal conductance, and 20% in transpiration. Root Zn concentration also increased significantly, with genotypes reaching 13 mg kg⁻¹. The genotypes MS053, DG745, and MS018 showed the most expressive improvements, with increases of up to 12.62 mg kg⁻¹ in root Zn concentration and 6.44 t ha⁻¹ in root yield. Starch content also increased in these responsive genotypes. These results highlight the potential of foliar Zn application, combined with the selection of responsive genotypes, as an effective strategy to increase both cassava productivity and nutritional quality. In addition, further studies are recommended to evaluate Zn bioavailability and its long-term performance under different environmental conditions.