The Rugose Virus Threat – Will it Affect Your Spring Crops?

Tomatoes infected with the Rugose virus. Photo courtesy of HortiDaily.

By now,  you may of heard of the Tomato Brown Rugose Fruit Virus (ToBRFV), referred to more simply as “Rugose”. It is a viral disease that predominately impacts tomato plants, but also peppers, leaving fruit damaged and unmarketable.

 

It was first detected in Israel in 2014 but has now been found in parts of North America.

If you are a Canadian ornamental grower that ALSO grows tomato liners as part of your spring crop selection, or if you grow ORNAMENTAL PEPPERS, here is what you need to know regarding Rugose symptoms, prevention and more importantly, regulations.

The Disease:

Although it does not pose a food safety risk, Rugose (ToBRFV) can be devastating to crops and challenging to control/eradicate when not acted upon swiftly.  Similar to Tomato Mosaic Virus (ToMV), it is highly virulent (i.e. spreads easily) and stable (i.e. persists in the environment).  It is currently only known to affect tomatoes and peppers, but its complete host range has not yet been established.

New Restrictions on movement of Tomato and Pepper:

Recently, the United States Department of Agriculture (USDA) issued a federal order regarding shipment of Tomato and Pepper plants (including plants for planting, seeds and fruit) to prevent the entry of ToBRFV to the United States.  This order may restrict export opportunities for Canadian ornamental growers on products such as ornamental or potted peppers, tomato seedlings, and tomato transplants. This federal order took place on November 22, 2019.  To review the full federal order please click here

In light of these new regulations, Flowers Canada is seeking information on export and production patterns for tomato and pepper plants from ornamental producers to better understand potential impacts to the industry.

Ornamental peppers, like pictured here, can also be a host for the Rugose virus. Photo from Paracho Ornamental.

If you or your farm plan to export tomato or pepper plants in the next year using the Canadian Greenhouse Certification Program (CGCP – yellow sticker program) or the program which will replace it (the United States-Canada Greenhouse Grown Plant Certification Program – GCP), please contact Flowers Canada.

 It is also recommended that you contact your local CFIA office for instructions regarding upcoming shipments.

On top of understanding upcoming shipment restrictions/regulations, it will be important for ALL greenhouse growers to know the signs and symptoms of the virus in order to act appropriately if infected plants are suspectedBiosecurity measures, such as inspection of imports and strict sanitation practices, will be key to preventing introduction/transmission of this pest.

ToBRFV fruit symptoms

Figure 1. ToBRFV fruit symptoms. (A-C) Symptomatic mosaic pattern on leaves of cluster tomato plants cv. Mose. (C) Narrowing leaves of cluster tomato plants. (D) Dried peduncles and calyces on cherry tomato plants cv. Shiran leading to fruit abscission. (E) Necrotic symptoms on pedicle, calyces and petioles cv. Ikram. (F) Typical fruit symptoms with yellow spots cv. Mose. (G-I) Variable symptoms of tomato fruits cv. Odelia. (G) The typical disease symptoms. (H) Symptoms of mixed infections by the abundant TSWV and the new tobamovirus isolate. (I) Unique symptoms of the new tobamovirus isolate found at a single location at Sde-Nitzan village. Photos by Neta Luria et al./PLOS https://creativecommons.org/licenses/by/4.0/

Symptoms of ToBRFV:

Symptoms on foliage (pepper or tomato) are similar to other Tobamoviruses (e.g. ToMV, TMV).   These include visible damage such as:

  • Cholorotic leaves
  • Leaf mottling
  • Narrowing or other deformation of leaves

Symptoms on tomato/pepper fruits include:

  • Blotchy yellow or brown spots
  • Necrotic spots
  • Fruit may be undersized or deformed; tomatoes may abort prematurely

Look for these symptoms on ornamental peppers, or tomatoes grown for spring sale. More information on symptoms of this disease, including photos, can be found at https://www.betterseed.org/wp-content/uploads/ToBRFV-QA.pdf

Biosecurity Practices to Limit ToBRFV:

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ToBRFV spreads primarily through mechanical transmission; it is incredibly easy to spread this virus simply by touching an infected plant.  The virus can also be spread by handling infected fruits. The virus can be easily spread from tomato to pepper plants in the same facility.

Rigorous and frequent hand washing by employees that regularly handle plants is the first line of defense, but may not be enough.  Other important measures to take to prevent the introduction/spread of ToBRFV include:

  • Rigorously inspecting incoming plant material (e.g. tomato transplants) for any viral symptoms
  • Confining potential host plants to a single area with a few dedicated workers; consider restricting access to essential personnel only
  • Regular monitoring
  • Wearing gloves when handling tomato/pepper plants or fruit
  • Using disposable lab coats
  • Disinfect regularly (e.g. tools, growing surfaces, foot baths, tire baths.). This also includes surfaces that are frequently touched by staff (doorknobs, keyboards, lunch tables, etc.).
  • Implementing strict visitor biosecurity – see OGVGs Visitor Biosecurity Guide here: https://www.hortcouncil.ca/wp-content/uploads/2019/04/Visitor-Biosecurity-Handout-EN.pdf
  • Quick removal of any plants showing irregular symptoms
  • Disinfection of growing areas between crops

Other Resources:

Please see the attached guide to cleaning and disinfecting your greenhouse, developed by Cara McCreary, Greenhouse Vegetable IPM specialist with OMAFRA, as well as a presentation with further background on ToBRFV.

Cleanout_07Nov2019_for distribution

ToBRFV_08Nov2019_for distribution

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