Figure 5.

Boxplots of (A) winter wheat grain yield and yield components [(B) kernels head^-1; (C) heads per plant; (D) heads m^-2; (E) kernels m^-2; and (F) thousand-kernel weight] at the agronomic optimum plant density (AOPD) as affected by yield environment (high, medium, and low), and tillering potential (TP; high and low). 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) quantile.