Adubação foliar e via solo de nitrogênio em plantas de milho em fase inicial de desenvolvimento

Abstract

Consider the most important nutrient in the increment of grain gield and also the proteic level, nitrogen (N), in addition of this fact, this nutrient is the component that most increases the production cost of maize crop. This study aimed to verify whether the application of leaf nitrogen influences the accumulation of proteins and parameters of growth of young plants of maize compared to the application of urea via soil. For both, young plants of the hybrid maize BR 206 received applications of urea as a source of N via leaf and soil at concentrations of zero, 0.5% and 1.0%. The plants were grown in a greenhouse being held three applications of N, the first for six days after the emergency (DAE) in a volume of 10 ml per plant and the following two to 10 and 14 DAE with 20 ml each. At 18 DAE the plants were collected and analyses proceeded. For plant height, root volum, leaf area, dry weigth of leaf area and root, one verified a higher efficiency of leaf fertilization, mainly at 0,5% level of urea. The application of urea 1,0% via soil caused a significative increase in leaf protein levels. These results suggest that leaf fertilization may be an efficient mode to complement what is uptaken by the roots, although it should not be used as a unique source of inorganic N to the plants.