Effect of light (dark or in an alternating regime of 8 h of light and 16 h of dark-ness) and temperature (constant 30◦C or alternating 30◦C for 8 h and 15◦C for 16 h)regimes on the germination of five switchgrass cultivars. Cultivars: upland, Cave-in-Rock and Trailblazer; lowland, Alamo, Kanlow, and low-dormancy Expresso.Columns represent total germination percentage means (TGP) after 14 d of incu-bation ± SE from 12 replications of 25 seeds. Values with the same letter are notsignificantly different at the 0.05 level of probability determined by Tukey’s HSD.Multiple comparison tests were done among the TGP (light/dark + light) means