ETHYLENE-ENHANCED, LIGHT-ENHANCED, AND PRECHILL-ENHANCED GERMINATION OF ECHINACEA-AUGUSTIFOLIA SEEDS

Echinacea angustifolia DC., the common coneflower of the western Great Plains, is difficult to propagate by achenes due to inherent seed dor mancy. The effects of light and prechilling on seed germination were e xamined, alone and combined with scarification (mechanical, acid) and ethylene (ethephon) treatments. The results showed that a 2-week prech ill treatment combined with ethephon and continuous light, followed by a 2-week germination period in light (16 hours per day) at 25C, could induce >95 % seed germination in E. angustifolia. This was a signific antly higher percentage of germination over a shorter period of time t han any other method examined or previously described. This treatment also synchronized germination, with most viable seeds germinating in < 1 week after being placed at 25C in the light. Chemical name used: 2-c hloroethylphosphonic acid (ethephon).