How to Manage Pests
UC Pest Management Guidelines
Pathogen: Lettuce chlorosis virus (LCV); Lettuce infectious yellows virus (LIYV)
(Reviewed 11/05, updated 1/10)
In this Guideline:
SYMPTOMS AND SIGNS
Symptoms of these viruses are similar to those caused by aphid-transmitted Beet yellows virus. Early symptoms are a very mild mottle that later develop into interveinal yellowing or reddening. Affected plants are stunted. Vascular rings in roots are brown and mature taproots often appear to be pithy.
COMMENTS ON THE DISEASE
Lettuce infectious yellows used to be a problem on sugarbeets grown in the Imperial Valley. It was transmitted by the sweetpotato whitefly, Bemisia tabaci, which has been displaced by the silverleaf whitefly, Bemisia argentifolii (aka B. tabaci, Biotype B– a nonvector of this virus). Currently, lettuce infectious yellows is not a major concern and has not been observed in the field since the early 1990s. Lettuce chlorosis virus is not uncommon in the Imperial Valley, but it has not been associated with yield loss in sugarbeet.
Lettuce infectious yellows is no longer a field problem in sugarbeets, and controls are not deemed necessary for lettuce chlorosis.
UC IPM Pest Management Guidelines:
S. Kaffka, Agronomy and Range Science, UC Davis
Acknowledgement for contributions to Diseases:R. T. Lewellen, USDA, Salinas
C. A. Frate, UC Cooperative Extension, Tulare County