Fig. 2. The effect of number of species planted on yield (g m^–2), and rhizome and roots mass (g m^–2) of 8 mixtures of quackgrass (QG) and orchardgrass (ORG) and/or white clover (WC) at 2-wk or 6-wk cutting. Symbols are means of 6 observations (3 replicates and 2 experiments); *, significance of regression P 0.05.