Dormant, intact Avena fatua L. (wild oat) seeds germinate poorly at 20°C. Removing the hulls slightly increased germination. Treatment with smoke solutions increased the germination of both intact seeds and caryopses. Exogenous GA 3 , alone or in the presence of smoke solution, increased the germination of caryopses, while ACC shows a tendency to increase germination of caryopses only when applied in combination with smoke solution. Results suggest that GA 3 and ethylene, but not smoke solutions, are involved in the regulation of a-amylase activity during germination. However, the participation of smoke solutions in the control of ACC oxidase activity cannot be excluded.