Germination after 14 days at 30◦C was 5% and extending the study to 28 days only had 7% germination (Table 1). These results indicate that 30◦C induces secondary dormancy in freshly harvested seeds. In addition, incubating seeds at 30◦C for 14 days and then transferring to 15/30◦C resulted in 28% germination compared to 58% for 15/30◦C after 28 days (Table 1). Therefore, first imposing secondary dormancy at 30◦C was only partially broken by the conducive alternating temperature regime. Increased percentage of dormant seeds and the depth of dormancy was reported for switchgrass seeds conditioned at 30◦C, requiring longer periods of stratification to break dormancy (Shen, 1997). Mechanisms by which temperature can induce secondary dormancy have bee