Cause The Bean leaf roll virus, which the pea aphid transmits from alfalfa, the overwintering host, to peas. The disease is not seedborne. The disease virtually eliminated susceptible pea lines and varieties in southern Idaho in 1980 and continues to be destructive in irrigated areas of Idaho, Washington, and Oregon.
Symptoms Infected plants develop a chlorotic mottling in terminal foliage, which may become bright yellow in time. Stunting frequently occurs, and plants may die if infections occur early in the season. Yields may be drastically reduced.
Cultural control Plant resistant varieties. Many varieties currently available have resistance to Bean leaf roll virus, and other resistant varieties are being developed.
Chemical control Applying insecticide to control the insect vector may help some. See the PNW Insect Management Handbook for details.