Ithaca, New York
March 4, 2003

Many New York state dairy farmers, who have suffered for two decades without affordable, disease-resistant forage to supplement grass for their animals, are getting their fields of dreams: Cornell University agricultural scientists and Cornell Cooperative Extension (CCE) researchers have developed a birdsfoot trefoil that fends off the devastating fungus, fusarium wilt.

Seeds of the new legume variety, Pardee birdsfoot trefoil, will be available this growing season on a large scale for cattle, sheep, goats and horses. The seed pods on the Pardee trefoil are shaped like
a bird's foot, hence the name.

Because of the absence of birdsfoot trefoil, dairy farmers in the state's Lake Champlain Valley and in Erie and Wyoming counties have been forced to buy more expensive forage or to invest in additional
grass seed and nitrogen fertilizer, says William Pardee, Cornell professor emeritus of plant breeding, and the variety's namesake.

The seed industry suggested the name as a way of thanking Pardee for years of extension help. Says Bruce Tillapaugh, a program leader with CCE in Wyoming County, "We're hoping the Pardee birdsfoot trefoil will be put on the farmer's buffet table and take its rightful place among the forage choices available."

The plant returns season after season and farmers can grow it in poor soil conditions. This will enable dairy producers to improve their financial margin, according to Pardee. "If dairy farmers can grow this forage to supplement their grass, rather than growing just straight grass, they will be way ahead," he says.

Alfalfa is the preferred forage crop because it has a higher yield potential and, as silage, makes a high-protein, tasty feed. Alfalfa also improves soil structure for future grass and grain crops. However, alfalfa does not grow well on poorly draining soil, thus the need for a disease-resistant birdsfoot trefoil.

Fusarium wilt kills the plant by clogging the vascular system. Over the years, some seed-production companies in the affected areas have moved their birdsfoot trefoil operations to the upper Midwest to
avoid the fungus. Research on combating the wilt began three decades ago. The late Carl Lowe, Cornell professor of plant breeding, and Kenneth Zeiders, a former U.S. Department of Agriculture employee at Pennsylvania State University, had collaborated on birdsfoot trefoil research in the 1970s and 1980s, selecting stock that seemed resistant to fusarium wilt. After they retired, research lay dormant for several years.

Tillapaugh was the catalyst for restarting the research. In 1990, when he was a Cornell graduate student in crop and soil sciences, he began conducting studies on the legume under the direction of Robert Lucey, now a Cornell professor emeritus of crop and soil sciences. Tillapaugh also worked with Gary C. Bergstrom, Cornell professor of plant pathology; David Kalb, a former Cornell researcher in plant pathology; and with Donald Viands, Cornell professor of plant breeding.
 
The first step was to understand the fungus. "It is a highly specific pathogen. The strain of fungus that causes wilt of birdsfoot trefoil is different from related strains that cause wilt on alfalfa or other legume plants," says Bergstrom. "We took all the birdsfoot trefoil varieties common in the marketplace -- the best of what we had -- and found that none stood up to fusarium wilt." However, he says, the fungus had a milder effect on seed used in the earlier research by Zeiders and Lowe.

Viands's laboratory took cultures of the fungus and exposed many birdsfoot trefoil plants to the fungus. The plants that survived were selected as parents for the next generation. Jill Miller-Garvin, previously a Cornell researcher in plant breeding, developed the final stages of the trefoil, giving the plants higher levels of resistance. In the field, Viands and Miller-Garvin selected plants for vigor. Julie Hansen, Cornell researcher in plant breeding, found that Pardee birdsfoot trefoil yields up to twice as much forage compared with other varieties.

The seed will be available in New York state through Agway Farm Seed, Syracuse and Seedway Inc., Hall.