To develop tools for the efficient and accurate detection of viruses in SK pulse crops. To determine the frequency of plant pathogenic viruses in SK pulse crops. To quantify yield effects of Bean Yellow Mosaic Virus (BYMV ) and Pea Seedborne Mosaic Virus (PSbMV ) in important pulse crop varieties. To document the symptoms of important pulse viruses, including BYMV and PSbMV on important SK pulse crops and varieties. To test the vector capacity of pea aphid for transmitting BYMV and PSbMV to important pulse crop varieties. To examine the population genetic variation of PSbMV among North American growing regions.