How to Manage Pests

UC Pest Management Guidelines


Turnip Mosaic

Pathogen: Turnip mosaic virus

(Reviewed 4/17, updated 4/17)

In this Guideline:

Symptoms AND SIGNS

Early symptoms of turnip mosaic include numerous small, light green, circular and irregular lesions on leaves. Later symptoms include veinal chlorosis, curvature of the midrib, asymmetrical distortion of the leaf blade, and necrosis of lower leaves. Lettuce infected early may be severely stunted, and can result in unmarketable heads.

Comments on the Disease

Turnip mosaic virus (TuMV) is not a common disease of lettuce. Other hosts, such as escarole and endive, are likewise rarely infected in California. However, the virus has a wide host range. It is found in 20 plant families and is especially common in crucifers.

Turnip mosaic virus is transmitted in a nonpersistent manner by many species of aphids. The virus is not seed transmitted.


Grow resistant crisphead lettuce varieties. Butterhead, leaf, or romaine lettuce types are all resistant.


[UC Peer Reviewed]

UC IPM Pest Management Guidelines: Lettuce
UC ANR Publication 3450


S. T. Koike, UC Cooperative Extension, Monterey County
T. Turini, UC Cooperative Extension, Fresno County

Acknowledgment for contributions to Diseases:
R. M. Davis, Plant Pathology, UC Davis

Top of page

Statewide IPM Program, Agriculture and Natural Resources, University of California
All contents copyright © 2017 The Regents of the University of California. All rights reserved.

For noncommercial purposes only, any Web site may link directly to this page. FOR ALL OTHER USES or more information, read Legal Notices. Unfortunately, we cannot provide individual solutions to specific pest problems. See our Home page, or in the U.S., contact your local Cooperative Extension office for assistance.

Agriculture and Natural Resources, University of California

Accessibility   Contact webmaster.