Grain mineral composition is important for the establishment of appropriate fertilizer levels, as well as to define the nutritional quality of food and physiological quality of seeds. The objective of this study was to evaluate the effect of ammonium sulfate (AS) and trinexapac-ethyl rates on mineral composition of wheat grains (Triticum aestivum L.) cv. Pioneiro. The experiment was carried out in Viçosa, Minas Gerais State, Brazil, from June to October 2006. The treatments consisted of five AS rates (150 kg ha-1, 300 kg ha-1, 450 kg ha-1, 600 kg ha-1, and 750 kg ha-1) combined with four trinexapac-ethyl rates (0 g ha-1, 62.5 g ha-1, 125 g ha-1, and 187.5 g ha-1). The experiment was arranged in a randomized block design with four replications. AS rates increased the concentrations of total-N (protein), Ca, S, Cu, and Zn and decreased the concentrations of P, K, and Mn (at AS rates above 457 kg ha-1). The Mg and Fe concentrations were not influenced by AS rates. Trinexapac-ethyl increased total-N, P, and Mn; reduced Ca; and had no influence on the concentrations of K, S, Cu, Zn, Mg, and Fe. It can be concluded that AS application improves the nutritional quality of grains, while the use of the growth retardant trinexapac-ethyl has no influence on its mineral composition.
Triticum aestivum L; nutrition; growth retardant