Dormancy of Wild Oat Seed Produced under Various Temperature and Moisture Conditions

Four greenhouse trials were conducted to determine the effects of various growth temperatures and soil moistures on dormancy of primary seed of selected strains from two wild oat (Avena fatua L. ssp. fatua (L.) Thell.) varieties. Both higher temperature and lower level of moisture decreased dormancy, temperature having a greater effect than level of soil moisture. The dormancy difference between seed produced on plants grown at 15.6 to 18.3 C in soil with approximately 75% or from 100 to 75% available moisture and at 25.3 to 28.4 C in soil with approximately 25% or from 100 to 25% available moisture ranged between 31 and 100%, dormancy tests being conducted 10 or 14 days after seed maturity. The magnitude of the difference in seed dormancy caused by conditions of growth was affected by strain and variety of wild oat, and by age of seed.