Selecting Non-dormant Alfalfa for Winter Hardiness
Alfalfa (Medicago sativa L.) adapted to the Midwestern United States typically becomes dormant in autumn to allow the plants to survive the stresses of winter. Plants that do not have a dormancy response are not winter hardy, but they produce more biomass during the late summer and autumn. Trying to get high autumn yield together with excellent winter hardiness has been a goal of alfalfa breeders for many years, but it is difficult to achieve. One possibility is to select for winter hardiness in non-dormant varieties. They may produce more yield in the autumn than currently available varieties. Also, because the non-dormant varieties are not related to varieties adapted to Iowa, they may be useful in the development of hybrid alfalfa. The objective of this study was to determine if selection within non-dormant cultivars for winter hardiness is possible.