Lettuce big-vein disease causes leaf distortion and ruffling in affected lettuce plants.
This disease was first associated in 1983 with a rod-shaped virus named lettuce big-vein associated virus (LBVaV), which is transmitted by the obligately parasitic soil-inhabiting fungus, Olpidium brassicae.
Symptoms
Affected plants have veins that become large and clear, causing the rest of the leaf to become ruffled. Severely infected plants may fail to form a lettuce head.
Control
- Grow disease-resistant cultivars.
- Use disease-free healthy seeds.
- Treat with methyl bromide, chloropicrin, or dazomet solution.