Nitrogen Fertilization on Maize Sowing: Plant Growth and Seed Vigor

The management of fertilization in maize plants is apreponderant factor in the search for higher yields and obtaining qualityseeds. In this sense, the study of nitrogen (N) management is predominant inimproving the efficiency of its application. The objective of this study was to evaluate thegrowth, partition assimilation and vigor expression of maize seeds submitted atdifferent doses of nitrogen applied at sowing. The treatments were constitutedby different doses of nitrogen fertilization at sowing, being: 25%, 50%, 75%and 100% of the recommended dose for the crop, according to the recommendationof nitrogen fertilization. The plants were collected at regular intervals of 21days after sowing until the end of the growth cycle. For the analysis of growthand partition of dry matter between the organs, the accumulation of dry matterand leaf area was measured. Theexperimental design was randomized blocks in a 4 × 7factorial scheme (four N rates at sowing and seven collection times with threereplications). The maizeplants under the influence of nitrogen fertilization at sowing presenteddifferential growth and distinct responses in the assimilated partition betweentheir structures, with the intensity dependent on the dose used. Plants grownusing 75% of the recommended dose of N at sowing had a higher relative growth rate, with more pronouncedeffects compared to the other doses. The expression of maize seed vigorincreases to an increase of 82.5% N at sowing.