Fig. 2. Yield of dry matter (DM) per plant for orchardgrass in 1997 and 1998 at three locations in Pennsylvania in response to plant spacing. Data points are averages of two cultivars and three replications with three radii per replicate. In 1997, slopes (b values) did not differ between Port Matilda and Rock Springs, whereas the slope for Kylertown was less (P < 0.05). In 1998, slopes for all locations differed. Asterisks indicate that slopes are different (P < 0.05) than zero.