How to Manage Pests

UC Pest Management Guidelines


Tobamovirus Diseases

Pathogens: Various Tobamoviruses (Tobacco mosaic virus, etc.)

(Reviewed 12/09 , updated 11/12 )

In this Guideline:


Symptoms on plants infected with Tobacco mosaic tobamoviruses and other tobamoviruses vary with specific viruses or strains, and depend on the temperature, light intensity, day length, and age of the plant. Symptoms can include necrosis on any plant part, defoliation, leaf distortion, and mosaic symptoms on leaves, stems, and fruit.


An important source of primary inoculum is contaminated seed. The virus is carried on the seed coat, and thus can be removed from contaminated seeds by washing seed with dilute solutions of tri-sodium phosphate. The tobamoviruses on pepper are readily spread mechanically within the field by handling and mechanical damage to plants, but not by insect, nematode or fungal vectors.

The tobamoviruses are very stable viruses. They can survive in plant debris for many years.


The best control is to use seed that has been treated to eliminate the seedborne inoculum. Minimizing plant handling and damage also is important for reducing field spread of tobacco mosaic virus. Good sources of plant resistance genes (L1-L4 genes) to various tobamoviruses also exist and are present in commercially available cultivars. No chemical strategies are effective.


[UC Peer Reviewed]

UC IPM Pest Management Guidelines: Peppers
UC ANR Publication 3460


S. T. Koike, UC Cooperative Extension, Monterey County
R. M. Davis, Plant Pathology, UC Davis
K. V. Subbarao, USDA Research Station, Salinas

Acknowledgment for contributions to Diseases:
B. W. Falk, Plant Pathology, UC Davis

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