How to Manage Pests
UC Pest Management Guidelines
Beet yellow stunt causes pronounced yellowing of older leaves; later, infected plants collapse prematurely and die. Internally, the phloem tissue of the stem and crown is brown and necrotic.
Host range of Beet yellow stunt virus includes plants in the families Chenopodiaceae, Asteraceae, Geraniaceae, Portulacaceae, and Solanaceae. Beet yellow stunt causes minor losses in most years, but occasionally is responsible for major losses in individual lettuce fields. The virus is transmitted by aphids. The sowthistle aphid, Hyperomyces lactucae, is the most efficient vector. Sowthistle (Sonchus spp.) is the primary source of the virus, and the disease is damaging only where large concentrations of sowthistle are present.
General weed control, especially of Sonchus spp., reduces the incidence of this virus in lettuce.
UC IPM Pest Management Guidelines: Lettuce