Efeito de doses de boro e zinco na absorção de nitrogênio e fósforo pelo algodoeiro em cultivo hidropônico

Abstract

Information about the effect of supply of B and Zn on concentration, uptake, transport and utilization of other nutrients in cotton crop are still very  limited. This study aimed to evaluate the effect of the concentration of B, Zn and their interaction on nutrient content, accumulation and the efficiency of uptake, transport and utilization of N and P by the cotton plant in hydroponic cultivation. The experimental design was completely randomized, with  three replications, in a 4 x 5 factorial with four concentrations of boron (0, 20, 40 and 80 µM L-1) and five concentrations of zinc (0, 1, 2, 4 and 8 µM L-1). Cotton plants were cultivated in a greenhouse, with a complete nutrient solution for 28 days, after which received modified solution in accordance with the treatment. At 115 days after emergence, the plants were harvested, divided into root, shoot and fruit, and subjected to chemical analysis. The results showed that the supply of B affected positively the nitrogen content of roots of cotton. The content and accumulated P in the shoot, root and boll of the cotton crop are influenced by the concentration of B. The presence of B decreased efficiency of phosphorus uptake and transport of phosphorus.