The bread-making quality of wheat is a highly complex trait that depends on both genetic and environmental factors. This study aims at evaluating the effects of different rates, time and splitting of nitrogen fertiliz...The bread-making quality of wheat is a highly complex trait that depends on both genetic and environmental factors. This study aims at evaluating the effects of different rates, time and splitting of nitrogen fertilization on the technological quality of wheat cultivated in the Brazilian Southern region. The samples of bread wheat （Triticum aestivum L.）, Onix, Quartzo and Mirante cultivars, were obtained through the use of nitrogen （N） fertilizer applied in doses of 36, 100 and 120 kg N ha1 at sowing, tillering and flowering. Laboratorial tests were carried out in a completely randomized design with four repetitions. The parameters analyzed were： grain yield, total protein, protein fractions, gliadins, glutenins, albumins and globulins, sulfur, gluten strength （W）, dough tenacity （P）, extensibility （L） and stability （S）, bread specific volume and bread firmness. While the content of total and reserve proteins is significantly increased with a higher rate and splitting of N, the content of metabolic proteins remains constant. A mean increase in the quality parameters W （24.37%）, L （14.86%） and P （11.59%） among cultivars was noticed after application of 120 kg N ha1, split at sowing, tillering and flowering. Bread specific volume increased, while bread firmness decreased with a higher rate of N fertilizer. Wheat fertilization with high doses of N does not cause induction to S deficiency in the grains. Not only increasing the N fertilization rate, but also splitting the N rate had a beneficial effect on the technological quality of wheat.展开更多
文摘The bread-making quality of wheat is a highly complex trait that depends on both genetic and environmental factors. This study aims at evaluating the effects of different rates, time and splitting of nitrogen fertilization on the technological quality of wheat cultivated in the Brazilian Southern region. The samples of bread wheat （Triticum aestivum L.）, Onix, Quartzo and Mirante cultivars, were obtained through the use of nitrogen （N） fertilizer applied in doses of 36, 100 and 120 kg N ha1 at sowing, tillering and flowering. Laboratorial tests were carried out in a completely randomized design with four repetitions. The parameters analyzed were： grain yield, total protein, protein fractions, gliadins, glutenins, albumins and globulins, sulfur, gluten strength （W）, dough tenacity （P）, extensibility （L） and stability （S）, bread specific volume and bread firmness. While the content of total and reserve proteins is significantly increased with a higher rate and splitting of N, the content of metabolic proteins remains constant. A mean increase in the quality parameters W （24.37%）, L （14.86%） and P （11.59%） among cultivars was noticed after application of 120 kg N ha1, split at sowing, tillering and flowering. Bread specific volume increased, while bread firmness decreased with a higher rate of N fertilizer. Wheat fertilization with high doses of N does not cause induction to S deficiency in the grains. Not only increasing the N fertilization rate, but also splitting the N rate had a beneficial effect on the technological quality of wheat.
