Fig. 1. Harvest timing x harvest year interaction for total yield (TY) and switchgrass yield (Swg) at anthesis (An) and killing-frost (KF) harvests at three locations in South Dakota. Values are averaged across N rate. Fisher's protected LSD(0.05) values, to compare across harvest timing and harvest year, are shown above the respective bars for TY and Swg yield for each location. NS = not significant at 0.05 level of probability.