Steadfast Trefoil's a Survivor

The first commercial variety of birdsfoot trefoil in the world with both the ability to spread and to resist root diseases is now available.

Birdsfoot trefoil is a fine-stemmed, yellow-flowered forage crop that resembles alfalfa; but it tolerates poor soil conditions and abuse from grazing animals much better than alfalfa. It is palatable to animals, nutritious, and doesn't cause bloating that animals can get from other legumes.

"Steadfast is a fitting name for the new variety, because its ability to spread by rhizomes helps plants keep from being killed by root diseases that normally plague trefoil varieties," says Paul R. Beuselinck, an ARS plant geneticist.

In Morocco, in the late 1980s, Beuselinck discovered wild birdsfoot trefoil that produces rhizomes—underground runners that allow the plant to spread to new sites. The Moroccan wild types he collected contributed to the parentage of Steadfast, which was released jointly by ARS and the University of Missouri in 1995.

Rhizomes occur below the soil and can root and make new plants. Even if the original parts of the mother plant die from disease, new plantlets that develop from rhizomes allow the plant to survive and spread.

Root diseases have retarded the popularity of birdsfoot trefoil in the United States. "Over time, stands of American varieties without rhizomes will likely thin out. But stands of Steadfast, which has rhizomes, can be expected to thicken, making more forage available for animals," says Beuselinck.

The variety should do well in areas of intensively managed animal grazing systems for producers wanting a nonbloating, cool-season legume as a component of their grass-based pastures.

"Producers can use it on acres now planted only in grass or that are considered unimproved," says Beuselinck. Peterson Seed Company, Inc., in Savage, Minnesota, has obtained an exclusive license to sell and distribute Steadfast. — By Linda Cooke, ARS

Paul R. Beuselinck is in the USDA-ARS Plant Genetics Research Unit, University of Missouri, Columbia, MO 65211; phone (573) 882-6406.