Effects of Temperature on Germination of 10 Native Legume Species

Abstract

Seeds of 10 species of legumes native to Missouri germinated poorly when the temperature was lower than 15 °C (59 °F). The fastest time to first germinated seed occurred at 20 °C (68 °F) for all species except purple and white prairie clover, which germinated first at 25 °C (77 °F). The fastest germination rate was first reached at 20 °C (68 °F) for hoary tick clover, sessile tick clover, and slender lespedeza, at 25 °C (77 °F) for white prairie clover, purple prairie clover, panicled tick clover, hairy lespedeza, and tall lespedeza, and at 30 °C (86 °F) for Illinois bundleflower and roundhead lespedeza. Maximum total germination percentage also varied among species. For both the prairie clovers and roundhead lespedeza, hairy lespedeza, and slender lespedeza, the lowest temperature at which maximum total germination percentage occurred was 15 °C (59 °F). For Illinois bundleflower and the 3 tick clovers, the lowest temperature at which maximum total germination percentage occurred was 20 °C (68 °F). For most species, the fastest germination rate occurred at a higher temperature than the maximum germination percentage. Many species attained maximum germination percentage and fastest germination rate across a range of temperatures rather than at a single optimal temperature. Species that rapidly and completely germinate across a wide range of temperatures should germinate more reliably under variable soil conditions than species that exhibit a narrow range.