Within the last several days, USDA has issued new guidance on an emerging viral disease of tomato and pepper (link). Tomato brown rugose fruit virus (ToBRFV) is a new tobamovirus (in the tobacco mosaic virus family) first documented in Israel in 2014. Since then, ToBRFV has also been found in Mexico, China, and several European locations. To prevent ToBRFV from significantly affecting tomato and pepper production in the U.S., restrictions on seed and fruit importation have been put in place by the USDA’s Animal and Plant Health Inspection Service.
ToBRFV has the potential to cause 100% loss in tomato and pepper crops. ToBRFV can be transmitted via seed or mechanically, such as by handling infected plant material then handling an uninfected plant. This includes potential for transmission from handling infected fruit from off the farm. In addition, bumblebees have been shown to transmit ToBRFV during normal pollination activities (Levitzky et al. 2019).
Greenhouse tomato and pepper producers in Kentucky should take several actions. All tomato and pepper producers should evaluate their planting material source. International sources of seed are not recommended. Transplants with viral symptoms should not be put into production. Records regarding scouting and plant handling (by whom and when) should be maintained for every crop.
For growers with active production, thorough scouting of the greenhouse should take place at this time and regularly throughout the season. Primary symptoms of ToBRFV on tomato include brown rugosity (a, d) or semi-circular yellowing on fruit (b, c), with mosaic or mottling patterns on leaves (e, f, g). As with all viruses, symptoms will be most severe on young plant tissues, such as newly formed leaves, blossoms, and developing fruit. Pepper symptoms vary slightly to include bubbling on leaves and brown or black areas on fruit. Growers should contact their county Extension agent as soon as possible if virus symptoms are observed in their actively growing crop. In most cases, the Extension agent will help facilitate sample submission to the Plant Disease Diagnostic Laboratories for evaluation.
For more information, please see the following:
- Federal Order for U.S. Imports of tomato (Solanum lycopersicum) and pepper (Capsicum spp.) hosts of Tomato brown rugose fruit virus (ToBRFV) (https://content.govdelivery.com/accounts/USDAAPHIS/bulletins/26cc7ae).
- Dombrovsky and Smith, 2017; https://creativecommons.org/licenses/by/3.0/
- Levitzky et al. 2019; PLoS ONE 14(1): e0210871. https://doi.org/10.1371/journal.pone.0210871
By Emily Pfeufer, Extension Plant Pathologist