a1 Research Geneticist, USDA-Agricultural Research Service, 303 Johnson Hall, Washington State University, Pullman, WA 99164-6434.
Disease resistance, increased crop residues and altered plant and canopy design are the primary strategies being used to solve the major problems of cool season food legumes that are an integral component of cropping systems in the rainfed areas of the U.S. Pacific Northwest. Dry pea, seed pea and lentil predominate among these legumes, but there is increasing interest in chickpea. Several diseases are major hazards to production, including root rots, wilts, powdery mildew, Ascochyta blight, and viruses. Pea and lentil cultivan resistant to root rots, wilts, and powdery mildew are being developed and released. Progress is being made on resistance to v iruses transmitted by aphids, including pea enation mosaic and bean leaf roll. Development of res istant cultivars has been the principal control strategy for several diseases: Ascochyta blight of chickpea and lentil; root rots and wilts of pea, lentil, and chickpea; powdery mildew of pea; and viruses of pea and lentil. Chickpea cultivars resistant to Ascochyta blight were recently made avallable to producers. Another problem is that crop residues are insufficient to control erosion. Research is underway on genetically increasing biomass and residue production in lentil and dry pea and on producing more lignified stems and other plant parts that are more resistant to breakdown during harvesting and subsequent tillage. Increased biomass also might increase grain yields and red uce harvesting losses. The semi-leafless and woody stem traits in pea, the bushy plant types of lentil and chickpea, and diverse pod traits in all the legumes have shown promise for increased yield potential, ease of harvest, and reduced shattering losses.