Alfalfa - Varieties

Varieties

Considerable research and development has been done with this important plant. Older cultivars such as 'Vernal' have been the standard for years, but many better public and private varieties better adapted to particular climates are available. Private companies release many new varieties each year in the US.

Most varieties go dormant in the fall, with reduced growth in response to low temperatures and shorter days. 'Nondormant' varieties that grow through the winter are planted in long-seasoned environments such as Mexico, Arizona, and Southern California, whereas 'dormant' varieties are planted in the Upper Midwest, Canada, and the Northeast. 'Nondormant' varieties can be higher yielding, but they are susceptible to winter-kill in cold climates and have poorer persistence.

Most alfalfa cultivars contain genetic material from sickle medick (M. falcata), a wild variety of alfalfa that naturally hybridizes with M. sativa to produce sand lucerne (M. sativa ssp. varia). This species may bear either the purple flowers of alfalfa or the yellow of sickle medick, and is so called for its ready growth in sandy soil.

Most of the improvements in alfalfa over the last decades have consisted of better disease resistance on poorly drained soils in wet years, better ability to overwinter in cold climates, and the production of more leaves. Multileaf alfalfa varieties have more than three leaflets per leaf, giving them greater nutritional content by weight because there is more leafy matter for the same amount of stem.

Wisconsin and California and many other states publish alfalfa variety trial data. A complete listing of state variety testing data is provided by the North American Alfalfa Improvement Conference (NAAIC) State Listing as well as additional detailed alfalfa genetic and variety data published by NAAIC.