de Brito Melo F, Antunes de Souza H, Alves Bastos E. Critical levels and sufficiency ranges for leaf nutrient diagnosis incowpea grown in the Northeast region of Brazil. Rev. Ciênc. Agron. 2020;51(4):1-9. Acesso em setembro 20, 2026. https://periodicos.ufc.br/revistacienciaagronomica/article/view/88831