Figure 2.

Dry weight (A), chlorophyll concentrations (B), and N contents in flag leaves (C), thousand grain weight (D), grain yield (E), and N contents in grains (F) of winter wheat as affected by the supply of nitrate- or ammonium-based fertilizer (80 kg N ha⁻¹) at anthesis (EC65). Bars represent the means of 4 independent replicates ± SD, and 4 plants per replicate. Means followed by different letters indicate significant differences between treatments according to One-Way (D,E) or Two-Way ANOVA (A,B,C,F) followed by Tukey's test (P ≤ 0.05). In (B) and (C), different lower-case letters indicate significant differences between harvest points within each N treatment, whereas different upper-case letters indicate significant differences among N forms within each harvest point (green or senescent leaves; immature or mature grains). The absence of letters indicates no significant difference for main factors or their interaction according to One-Way (D,E) or Two-Way (A) ANOVA.