Effect of storage temperature, storage duration and germination temperature on the dormancy of seed of Avena fatua L. and Avena barbata Pott ex Link

Seed collected from genotypes of A. fatua and A. barbata naturalized in the northern, intermediate and southern latitudes of the temperate zone of Western Australia was tested for ecotypic variation under differing temperatures of summer storage and subsequent germination. The predominance of A. fatua in cereal crops is considered to be due largely to its well-developed seed dormancy. This characteristic is virtually absent in A. barbata, and this species does not norn~ally survive crop-land preparation. The level of seed dormancy and its rate of dissipation in both species is related to the geographic origin of the seed. That from the south of the temperate zone is more dormant than that from the north. Dissipation of dormancy in both species appears to be a function of time, temperature during storage or at germination having only a limited effect.