How to Manage Pests

Pests in Gardens and Landscapes

Virus Diseases — Beet western yellows, Curly top, Cucumber mosaic, Lettuce infectious yellows, and Lettuce mosaic

Many viruses are difficult to distinguish from one another by symptom alone. In addition, for each particular disease, the symptoms will vary greatly depending on stage of plant at time of infection and other factors. In general, symptoms consist of various leaf and plant deformities, stunting and poor growth, and yellowing or a mosaic or mottling pattern in the leaves. Identification of the particular pathogenic agent can only be made with serological, inoculation, or other laboratory tests.

Life cycle


Buy and plant virus-free seed if available. Resistant varieties may be available. After symptoms on plants occur, there is no practical control. Reflective mulches or row covers may help prevent infection by aphid- and leafhopper-transmitted viruses. Plants showing symptoms near harvest are edible. Plants that show symptoms early may be small or may not form heads.

Plants infected with virus

Plants infected with virus

Hollow stem damage caused by rapid growth disorder.

Spinach plant infected with virus

Statewide IPM Program, Agriculture and Natural Resources, University of California
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