The wild oat (Avena fatua L.) is one of the most common annual weed species in the northern portion of the great plains region of North America. It has been estimated that up to 70 bushels per acre of wild oat seeds occur in the soil of seriously infested fields. As an impurity in threshed grain it frequently amounts to 10 per cent or more as dockage. To become a serious problem under the climatic conditions and cropping practices of this region, the seed of an annual weed such as wild oats must undergo a period of dormancy and require exacting conditions for its germination. Therefore, investigations to study the factors affecting dormancy and the optimum conditions under which weed seeds will germinate have received considerable attention.