| Cover crops are an important innovation in sustainable cropping systems. The successful use and management of black medic (Medicago lupulina L.) as a self-regenerating cover crop requires a better understanding of its physical seed dormancy. In order to break this seed dormancy, it appears that a low temperature 2-stage seed softening process is required. However, whether or not this 2-stage process is required for black medic seed softening in Western Canada is unclear. Also, the influence of the presence of a companion crop, medic population type, seed burial depth and seed production environment on black medic production and seed softening is unknown. Field and controlled environment studies were established in 2003 and 2004 in an effort to address these questions.; The results from a field study conducted in different prairie environments showed that although, seed production environment, the presence of a companion crop, and medic population affected the growth and development of the black medic plants, they did not affect initial seed dormancy. A second field study tested the effect of seed production environment, seed burial depth and population on seed softening. (Abstract shortened by UMI.)... |
