SEED DORMANCY IMPLICATIONS IN GRAIN AND FORAGE PRODUCTION

Seed dormancy has been described for many species, and has promoted th e curiosity of ecologists, who have recorded in detail the conditions and periods where seed dormancy is present. Physiologists have focused on understanding the mechanisms involved in seed dormancy induction a nd release. Agronomists have found seed dormancy to be problematic sin ce it is related to the development of persistent weed seed banks and to the problems in predicting establishment of weed stands. If the cro p seed has dormancy, its germination is restricted to a very narrow ra nge of micro-environmental conditions. In this paper, we discuss bow s eed dormancy and the knowledge of its nature could be used to improve agronomic practices for grain and forage production. Crops selected to have dormant seeds, or artificially generated dormant seeds, could be sown at any time. When seedling establishment is desired, seed dorman cy level could be lowered to produce synchronic germination and seedli ng emergence by modifying the environment, (i.e., changing the light a nd thermal environment of the seeds) so that physiological changes cou ld occur and trigger germination. Seed germination could be naturally induced by seasonal changes or artificially induced by sonication. Sel ecting crops with dormant seeds during ripening and storage could also prevent seeds from germinating in moist environments. Artificially in duced seed dormancy could be achieved by spraying hormones or oils. Wi th adequate knowledge about the seed dormancy characteristics of plant populations, environmental situations can be engineered to encourage release from seed dormancy, to promote or inhibit certain species in w eed and range management.