Improving Germination of Native Legumes.

Native legumes could be used as forages in silvopasture systems in Appalachia because they may be more adapted than introduced legumes to local conditions. However, there is limited research on establishing native legumes which are often challenging due to low germination, hard seed, and slow germination. In this study, the five native warm-season legumes were: white prairie clover (Dalea candida Michx. ex Willd.), purple prairie clover (Dalea purpurea Vent.), showy tick-trefoil (Desmodium canadense [L.] DC.), panicled tick-trefoil (Desmodium paniculatum [L.] DC ), and slender lespedeza (Lespedeza virginica [L.] Britton). Seeds were germinated in incubators at one of four temperatures (10°C, 13°C, 16°C, and 19°C) for 21 days with three pre-sowing treatments (mechanical scarification, cold-moist stratification for 30 days, and a control--no treatment). Significant differences were calculated with Tukey’s HSD at α=.05 or less. Total germination percentage was highest at 16°C and 19°C for D. paniculatum and L. virginica, while for D. canadense and D. candida highest germination occurred at 13°C, 16°C and 19°C. For D. purpurea all temperatures tested yielded similar germination percentages, suggesting that it can be planted earlier than the other species. Mechanical scarification increased total germination percentage of D. canadense, D. candida and L. virginica as compared to the control. Stratification decreased germination percentage of D. candida, D. purpurea, and D. paniculatum. Germination rates increased for all species as temperature increased, with the fastest germination rate for all species at 19° C and the slowest germination rate for all species at 10° C. Mechanical scarification increased germination rates of all species as compared to the control treatment as did stratification for most species. For best stand establishment, warmer temperatures may increase seedling vigor by increasing germination.  Furthermore, seeds should be scarified to increase germination rates and in some cases, overall seed germination percentage.