Development and Germination of Barnyardgrass (Echinochloa crus-galli) Seeds

Abstract
Barnyardgrass [Echinochloa crus-galli (L.) Beauv. # ECHCG] spikelets were collected from greenhouse-grown plants at various developmental stages. Caryopses contained in a single spikelet were dormant at maturity, but dormancy was overcome when the spikelets were dry afterripened at 23 C or were treated with high temperatures, acid scarification, or punctured with a scalpel. The season at which anthesis occurred affected the length of time for afterripening. Enhanced germination due to puncturing and scarification was not related to removal of a restriction to water entry. The effectiveness of puncturing in overcoming dormancy depended on moisture content of the spikelets at the time of puncturing. Above 18% moisture content germination percentage was low regardless of the dormancy-releasing treatment.