HAIRY VETCH IMPROVING WINTERHARDINESS

Albert Lea Seed is working the University of Minnesota on a promising new variety of hairy vetch. Our grower/research partners at Prairie Sky Farm are increasing that new variety this year in Wesley, Iowa.

GUEST CONTRIBUTOR Nick Wiering

Graduate Research Assistant Dept. of Agronomy & Plant Genetics University of Minnesota

What Is Hairy Vetch & Why Should Farmers Care?

Hairy vetch (Vicia villosa R.) is a member of the vetches, which were among the earliest groups of plants domesticated by humans. It can more reliably overwinter compared to other legume cover crops (e.g. winter pea, crimson clover) and has the potential to provide >150 lbs. N per acre if grown to maturity because of the high N content within its tissue. Like other cover crops, hairy vetch can further provide ecosystem services such as reducing soil erosion and improving soil health. It is also an excellent source of food for pollinators, especially bumblebee species.

Why the Focus on Hairy Vetch?

The UMN hairy vetch breeding program was initiated to develop a winter-hardy legume cover crop specifically for Minnesota cropping systems. Legumes are a valuable component to any cropping system because they have the unique ability to convert atmospheric N into plant-usable N in collaboration with soil microbes. However, few winter-annual legumes are able to reliably overwinter in the harsh extremes that Minnesota has to offer. If the plants cannot survive, the full benefits of cover crops cannot be realized. Hairy vetch, which originates from higher altitudes and latitudes in Eurasia, is likely the best candidate to fill this void in the Upper Midwest because it is the most winter-hardy cultivated annual legume. However, until recently there has been little knowledge about what seed sources of hairy vetch are best adapted to northern Midwest conditions.

What Is the Breeding Program Trying to Solve?

Cover crops have had few resources allocated towards their improvement compared to major commodity crops like corn, wheat, and soybean. Many cover crop populations, including hairy vetch, still retain some weedy characteristics from their wild ancestors such as pod shatter and seed dormancy. In collaboration with the national Cover Crop Breeding Network, we are identifying plants that lack these characteristics and are finding the genes that may be responsible for them. Like other legume cover crops, hairy vetch can be slow to establish in the fall and regrow in the spring. To address this, our UMN program has aggressively selected for plants that can provide maximum biomass and ground coverage in the fall and early spring. Like any other breeding program, traits such as disease and pest resistance, biomass yield, and seed yield, are still important and carefully scrutinized to develop a wellrounded cultivar. Improving winter survival is a challenging task for any crop due to the underlying genetic complexity of the trait. Testing survival over numerous winters and locations is resource intensive, but generally necessary. However, the UMN team has developed indoor screening methods to measure freezing tolerance and are currently identifying anatomical and physiological mechanisms that influence winter-hardiness. With these methods, they hope to speed-up the process of developing winter-hardy cultivars.

Who Are the Key Players in the UMN Hairy Vetch Breeding Program?

Beginning in the mid-1990’s, Drs. Nancy Ehlke and Craig Sheaffer (Department of Agronomy and Plant Genetics, University of Minnesota) began gathering sources of hairy vetch from the National Plant Germplasm System and local farmers. They evaluated the winter survival of these seed sources over multiple years and environments to identify the most promising populations.

In 2015, they received funding through the Minnesota Department of Agriculture’s AGRI Crop Research Grant to use these elite populations as the foundation of a new MN hairy vetch breeding program. Nick Wiering, a PhD candidate working under Drs. Ehlke and Sheaffer, has been leading the breeding program since he joined the team in 2015 as a Master’s student.

In 2016, the UMN team joined forces with a USDAfunded cover crop breeding network (grant no. 2018- 51300-28424; covercropbreeding.com) focused on developing regionally adapted cover crops throughout the US. This objective is facilitated by a diverse network of researchers (i.e. academia, USDA, and private research institutes) that enables the exchange of knowledge and germplasm. This sort of collaboration will be vital for the continued improvement of hairy vetch and other legume cover crops.

“Hairy vetch is the most winter hardy annual legume cover crop. Many varieties consistently survive northern Midwest winters. When planted in August or September and killed in May, hairy vetch supplies nitrogen for demanding crops like corn. Hairy vetch also pairs well in a cover crop mix, if seeding rates of highly competitive companion grasses like rye and triticale are not too high. Despite its many benefits, hairy vetch can create major weed problems for rotations including small grains. The Cover Crop Breeding Network aims to release varieties with proven winter hardiness and soft seed. Until variety stated lines are available, however, be sure to source seed with documented winter hardiness in the northern Midwest and keep hairy vetch out of rotations with small grains.”

Lisa Kissing Kucek, PhD

Plant Research Geneticist USDA-ARS