Efeito do nitrogênio sobre o teor de ácido cianídrico em plantas de mandioca

Abstract

In order to evaluate the effect of nitrogen on the levels of HCN, chlorophyll, nitrogen and protein in cassava plants (Manihot esculenta Crantz), two experiments were carried out at the State University of Southwestern Bahia (in Vitória da Conquista, Bahia, Brazil). In this field study, six treatments of nitrogen were conducted (0, 50, 100, 200, 300, and 400 kg ha-1) on two varieties of cassava (Sergipe and Lisona), using experimental delineation in randomized blocks, with treatments arranged in a factorial scheme. Results showed the effect of nitrogen on the level of cyanhydric acid in the leaves, 90 days after sprouting. Variation in HCN was observed in the leaves at 180 days and in the tuber roots at 360 days, during the harvest. Other characteristics studied were not influenced by nitrogen dosages. The behavior of the same varieties of cassava, in nutritive solution with different levels of nitrogen (15, 30, 60, and 120 mmol mL-1), was evaluated for 60 days, in an experiment conducted in a greenhouse, using an entirely randomized delineation and factorial scheme. Effect of nitrogen on the levels of chlorophyll, nitrogen, and protein of the leaves was observed. The levels of HCN were not influenced by the levels of nitrogen studied. Effect of variety was observed on the levels of chlorophyll and HCN of the leaves.