Sweetvetch Seed Germination

Abstract

Sweetvetch (Hedysarum boreale Nutt. var. boreale) is a potentially important revegetation species for drastically disturbed lands and range improvements in western North America. The germination of sweetvetch was studied under various temperature, light, and moisture conditions. It was found that sweetvetch can germinate under a wide range of temperature and light conditions following physical scarification of the seed coat. Under constant temperatures optimum germination occurred at 15 degrees C and 20 degrees C, while under alternating temperature optimum germination occurred at 15-25 degrees C and 20-15 degrees C (for 8 hours and 16 hours, respectively, in each case). Dark treatments resulted in greater germination than light treatments. When temperature and light conditions were held constant and moisture conditions varied, the germination of sweetvetch declined rapidly at osmotic potentials below -7.5 bars.