Reacquaint yourself with tobacco mosaic virus symptoms

Greenhouse growers need to monitor plant material for symptoms of tobacco mosaic virus and take appropriate steps to prevent spread in the greenhouse.

Tobacco mosaic virus has an extremely large host range that includes many common greenhouse crops. To minimize losses from this, it is important for growers to be familiar with some of the symptoms and be knowledgeable about the disease.

The host range of tobacco mosaic virus includes petunia, calibrachoa, lobelia, impatiens, chrysanthemums, geraniums and tomatoes. Symptoms caused by tobacco mosaic virus vary greatly depending on the host. Symptoms may include yellowing of the foliage, necrotic leaf spots, mosaic symptoms, stunting and leaf distortion.

Tobacco mosaic virus
Tobacco mosaic lesions on a leaf.  Photo credit: Jan Byrne, MSU
Diagnostic Services.

Tobacco mosaic virus
Tobacco mosaic damage on a petunia plant. Photo credit: Jan Byrne, MSU Diagnostic

Tobacco mosaic virus
Distorted growth, a symptom of tobacco mosaic virus on petunia.
Photo credit: Margery Daughtrey, Cornell University.

Tobacco mosaic virus
Another symptom of tobacco mosaic virus on petunia is chlorotic mottle.
Photo credit: Maria Tobiasz, Cornell University.

Tobacco mosaic virus
Symptoms of tobacco mosaic virus on calibrachoa. Photo credit: Margery Daughtrey
and Maria Tobiasz, Cornell University

Unlike some of the other common viruses of ornamentals, tobacco mosaic virus is not vectored by insects. The virus can be spread by sap, through vegetative plant production and through mechanical means including rubbing or touching plants. 

Fungicides are not helpful in controlling this plant disease. Once plants are infected with a virus, they cannot be treated to eradicate the virus. Infected plants should be removed and destroyed to prevent further spread. Identifying infected plants can sometimes be challenging. MSU’s Diagnostic Services lab can test samples for tobacco mosaic virus with ELISA testing. Samples should be submitted using next day delivery and should not be mailed on a Friday.

Learn how to submit a sample or contact the lab at 517-355-4536 if you have any questions about submitting samples or the testing procedure. Most plant suppliers will reimburse growers for a lab test to confirm a disease so save your receipts if you send plants to the lab.

Common tobacco mosaic virus hosts

Begonia Geranium Osteospermum
Calibrachoa Impatiens Petunia
Chrysanthemum Lobelia Tomato
Gazania New Guinea Impatiens Verbena

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