Nitrogen application methods and doses in the development and yield of wheat

The objective of this work was to evaluate the effect of doses and methods of nitrogen application on the development and yield of two wheat cultivars. The experiment was conducted in Vicosa-MG, from May to September 2005, and it was arranged in a 2x2x5 factorial, randomized block design with four repetitions. The treatments consisted of the combination of the two wheat cultivars, BRS 210 and Pioneiro, two nitrogen application methods (total dose applied at seed sowing or 20 kg ha(-1) at sowing and the remaining as topdressing in the beginning of tillage) and five N doses (40, 60, 80, 100 and 120 kg ha(-1)) with ammonium sulfate as N source. Cultivar Pioneiro showed higher yield potential than cultivar BRS 210, but it was less resistance to lodging. Splitting nitrogen fertilization increased lodging and brought no benefit to grain yield. Grain yield response to N doses was quadratic, reaching maximum at 96.8 kg ha(-1), and linear increase in lodging of cultivar Pioneiro plants.