Winter-Hardiness and Yield Potential of Faba Bean (Vicia faba L.) Under Sub-Freezing Temperatures.

The Palouse region is known for its cereal and cool-season legume production in a dryland cropping environment. Fall planted Faba bean (Vicia faba L.) would be a good candidate for an alternative rotation crop due to its high N-fixing capabilities and potential to over-winter. The objectives of this study are to identify cultivars that are able to survive the winter and show highest yielding potentials and to identify plant characteristics that contribute to these high yielding capabilities. Evaluation of faba bean was undertaken in a replicated field experiment over the course of two years at two locations in Eastern Washington featuring subfreezing over-winter temperatures. Fifty-five cultivars were evaluated, forty-three collected from Afghanistan, Bulgaria, China, Finland, Hungary, Nepal, and Poland, maintained by the Western Regional Plant Introduction Station (WRPIS), and twelve of them, originating from Germany, France, and the UK, identified and/or bred for winter-hardiness. The cultivars showed different responses to cold varying from no leaf damage to total leaf damage. A one-to-four scale was used to score winter hardiness based on leaf damage. At 80 percent maturity, plots were harvested to find plot yield with subsamples taken for yield component analysis. Cultivars identified with better over-wintering capabilities were those identified and/or bred for winter hardiness originating in Germany, France, and the UK and those originating from Bulgaria maintained in the WRPIS germplasm collection. Grain yield was significantly correlated to winter hardiness score.