Germination response of hand-threshed Lehmann lovegrass seeds

Abstract

Germination of Lehmann lovegrass (Eragrostis lehmanniana Nees) was increased by seed after-ripening and by mechanical scarification of the seed coat. Hand-threshed seeds collected from 5 sites in southern Arizona were periodically germinated over the water potential range of 0 to -1.55 MPa for 98 weeks after harvest. Nonscarified seeds exhibited very low germination at all water potentials for the entire length of the study. Total percent germination of scarified seeds peaked after 34 weeks. Seeds scarified before the after-ripening requirement was met germinated without further scarification at 46 weeks after harvest. Measurements of water uptake rates indicate that seed cost permeability to water contributes little to the increased germinability of scarified seeds.