Mosaic (virus): Young plants first show a slight leaf rolling, followed by light green to yellow mottling. Foliage has a yellowish color and plants are small or dwarfed. Symptoms vary according to type or variety of lettuce. The virus is seed-borne and overwinters in wild hosts and weeds. Infected seed is the most common source of infection. Once infected plants are present in the field, aphids will continue to spread the virus. There is no cure for mosaic once a plant is infected. The control is to use virus-free seed.
