Fig. 1. Effect of different nitrogen treatments on ear diameter (cm), ear length (cm), and number of kernels per ear averaged over three hybrids of maize (Pioneer 3905, Pioneer 39F06 Bt, and Maizex LF850 RR). 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 parameter are not statistically significant at P < 0.05.