Fig. 3. Effect of nitrogen treatments on the nitrogen concentration (%) in different parts of a maize plant (g) averaged over three hybrids. The nitrogen treatments are N1, N supplied from V8 to maturity; N2, N supplied from seedling emergence to V8; N3, N supplied from seedling emergence to silking; N4, N supplied from seedling emergence to 3 wk after silking; and N5 (control), N supplied from seedling emergence to physiological maturity. The bars with the same letter within each plant part are not statistically significant at P < 0.05.