Mechanism of Dormancy in Pensacola Bahiagrass

Abstract

The rationale for this study was to characterize the dormancy factors that contribute to slow germination and poor stand performance in Pensacola bahiagrass ( Paspalum notatum Flugge). Several dormancy releasing treatments were ineffective. The importance of the lemma was established by excising parts of the seed covers. Removing the second glume and sterile lemma did not reduce dormancy. Removing the palea resulted in significantly improved germination but still not as rapid nor as complete as removing the lemma. Germination was observed to occur by the coleorhiza protruding through an opening in the lemma caused by the separation of fibers immediately above the embryo. Aging the seed increased germination and the number of seed with visible, separated fibers. A dormancy mechanism is proposed in which water uptake and the expansion of the embryo are restricted until an opening occurs in the lemma.