Cause The Beet yellows virus is perpetuated in members of the beet family but is not transmitted by seed. The virus persists in aphid vectors for 1 to 4 days.
Symptoms Young leaves show no symptoms at first. Vein yellowing or vein clearing is seen early in younger leaves. Leaves turn chlorotic, notably thickened, leathery, and brittle. Reddish spots appear between leaf veins, grow larger, and often merge. The leaves may have a distinct bronze cast. Infected plants often turn reddish or purplish, or the normal reddish or purplish color intensifies. Finally, about the time seeds are maturing, the plant is in general decline. Affected seed plants have poor root growth and are easily uprooted by a moderate wind. Their seed is smaller and has less vitality than seed from uninfected plants.
- In seed production fields, isolate steckling beds at the windward side of beet production fields (westward in the Skagit Valley) to prevent infecting the new crop.