Germination Requirements of Green Needlegrass (Stipa viridula Trin.)

Abstract

Germination requirements of green neddlegrass (Stipa viridula Trin.) were studied because of its potential for use in revegetation of disturbed lands. The effects of temperature, light, physiological, and mechanical treatments on germination of green needlegrass seed from 4 sources were examined to determine requirements for maximum germination and possible causes of dormancy. Optimum temperatures for germination were 20 degrees C (constant) and 20-15 degrees C (16 hr-8 hr alternation). Germination was highest in constant darkness. Greatest germination of the most dormant source occurred when seeds were either prechilled or treated with gibberellic acid and the lemma and palea was clipped with a razor blade. The results indicated that dormancy of green needlegrass seeds was associated with a deficiency of endogenous gibberellins and with mechanical and permeability restrictions imposed by the lemma and palea.