Absorption of calcium and magnesium by the cotton plant grown under different boron and zinc concentrations

Abstract

Many species and varieties of plants differ in their responses to nutrient availability in the growth medium. The causes of this difference reside in the capacity for absorption and utilization of nutrients. Information about the effect of supply of B and Zn on concentration, uptake, transport and use efficiency of other nutrients in plants of cotton are still very limited. This study aimed to evaluate the effect of B and Zn concentrations in nutrient contents, accumulation and efficiency of use of Ca and Mg by cotton grown in the nutrient solution. The experimental was conducted in completely randomized design, with three replications, in 4 x 5 factorial arrangement with four doses 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 green house, with complete nutrient solution for 28 days, after which received modified nutrient solution in accordance with the treatment. To 115 days after emergence, the plants were harvested, divided into root, shoot and fruit, and subjected to chemical analysis. The results led to the conclusion that the content of Ca in the root, the contents of Mg in the root and the fruit of the cotton plant are influenced by concentrations of B. The content and accumulation of Ca in the shoot are influenced by Zn concentration in the nutrient solution. B and Zn interaction affected the content of Ca in the root, the Mg content in shoot and in fruit, as well as the efficiencies of absorption, transport and use of Mg and Ca by cotton.