Figure 4.

Boxplots of (A) winter wheat grain yield and yield components [(B) heads per plant; (C, D) heads m^-2; (E, F) kernels head^-1; (G) kernels m^-2; and (H) thousand-kernel weight] as affected by plant density group (< 100, 100-200, 200-300, 300-400, and >400 plants m^-2), yield environment (YE; high, medium, and low), and tillering potential (TP; high and low). On panel b, boxplots within the same plant density group with the same letter are not statistically different (α = 0.05). On all other panels, boxplots with the same letter are not statistically different across all levels shown in the panel (α = 0.05). Boxplots portray the 5^th (lower whisker), 25^th (bottom edge), 50^th (solid black line), 75^th (top edge), and 95^th (upper whisker) quantiles.