Fall Dormancy of Alfalfa in Transplanted vs. Direct‐Seeded Nurseries 1

Fall dormancy of alfalfa cultivars and experimental synthetics is routinely evaluated by breeders to predict winterhardiness. Some researchers establish evaluation nurseries by direct‐seeding, followed by thinning the seedlings. Other researchers start seedlings in the greenhouse and transplant them to the field at the desired spacing. Transplants usually have highly branched root systems, whereas direct‐seeded plants primarily have a taprooted system. Because of these different types of root systems, transplanted and direct‐seeded plan~s were compared for fall dormancy by two experiments, one with 17 cultivars and the other with nine cultivars. Each cultivar was established by both transplanting and direct‐seeding in the spring. Fall dormancy of individual plants was rated according to plant height about 5 weeks after the last forage harvest (harvested 7 September). Correlation coefficients between transplant methods (r = 0.99, P<0.01 and r = 0.96, P<0.01 for fire two experiments) and non significant establishment method ✕ cultivar interactions clearly demonstrated that either method provides reliable fall dormancy evaluation of synthetics.