Boron-zinc interaction in the absorption of micronutrients by cotton

B-Zn interaction modifies the nutritional dynamics of copper (Cu), iron (Fe) and manganese (Mn) in cotton. This study aimed to evaluate the effect of B and Zn concentrations on the absorption of Cu, Fe and Mn in cotton plants cultivated in nutrient solution. The experimental design was completely randomized with three replicates, in a 4 x 5 factorial scheme, corresponding to four concentrations of B (0, 20, 40 and 80 µM L-1) and five concentrations of Zn (0, 1, 2, 4 and 8 µM L-1). At 115 days after emergence, the plants were collected, divided into roots, shoots and fruits, and subjected to chemical analysis. The results allowed to conclude that the Cu content and total Cu in the fruit, total Cu in the roots, Cu use efficiency, Fe content in the roots, Fe absorption efficiency, Mn content in the fruit and Mn absorption efficiency of cotton are influenced by the concentrations of B in the solution. The interaction between B and Zn affected total Fe in the roots, Fe content and total Fe in the fruit, Fe transport efficiency, total Mn in the shoots and Mn transport efficiency; in addition, Zn acts differently according to the supply of B and vice versa.