Germination characteristic of Silphium perfoliatum L. seeds

L. is a perennial and flowering crop that has been investigated in recent years for its potential as an energy plant, particularly for biogas production. A stand establishment by sowing of seeds is complicated, owing to the low germination capacity of untreated . L. seeds. Consequently, germination experiments were carried out with two- to four-factor levels to determine the effect of selected factors (medium, pretreatment, light, temperature, prechilling) on dormancy and germination of . L. seeds and to achieve maximum germination rate. All factors had a highly significant effect on germination. Germination experiments displayed a primary and physiological dormancy. Germination could be significantly increased by using a 0.05% GA solution during the imbibition phase, a light–dark cycle, alternating temperatures between 20°C and 30°C, and a wet stratification for seven days at 0°C. The experiments helped to fully exploit the germination potential and to develop a germination test method for . L.