Variability in germination rate among seed lots of Lehmann lovegrass.

Abstract

The regeneration success of Lehmann lovegrass (Eragrostis lehmanniana Nees) in southern Arizona may be partially due to rapid germination during sporadic periods of available soil moisture. There is limited information regarding germination rate of Lehmann lovegrass but it is known that total germination response for this species is highly variable. Some of this variability may result from differences in the degree of mechanical scarification during harvest, threshing, and storage. Scarified and nonscarified seed from 7 seed lots were germinated over the water potential range of 0 to -1.16 MPa. Results showed that mechanical scarification increased total germination and germination rate. Mechanical scarification reduced variability among seed lots for germination rate, but increased variability for total germination. The rapid germination hypothesis may be valid for Lehmann lovegrass as long as seed numbers are not limiting. Of the scarified seed that germinated above a water potential of -0.4 MPa, at least 10% did so between days 1 and 2 of the study.