Tomato brown rugose fruit virus: Growers’ checklist

The following lists the ‘best practice’ hygiene and biosecurity procedures identified from the study tours in Europe and Israel.

Implementing these practices may not be practically, or economically viable for all sites, but demonstrates what can be done to mitigate against ToBRFV infections developing, and how to better address infections that occur on sites.

• Review and update site hygiene protocols to include ToBRFV management practices, and train staff on ToBRFV symptoms and what to do if an outbreak occurs. Discuss this further with a local PHSI officer
• Stop all site visits unless essential. Where visits are required, request they take place first thing in the morning
• Ensure visitors read and understand site hygiene protocols, including wearing protective clothing at all times, ideally changing into this before leaving their vehicles. Where sites are visited by individuals frequently, shoes can be purchased to remain on site and be routinely disinfected
• Consider supplying fresh, laundered clothing for staff to wear during shifts, which is replaced each day
• Staff should wear gloves at all times, replacing them often, and frequently sterilise their hands with an appropriate disinfectant
• When using contractors, ensure their equipment is clean and sterilised before allowing entry on site
• No tomato products should be brought onto, or consumed on site – by staff or visitors
• Limit staff movement between production areas on each site, do not move equipment or machinery between areas. Identify and designate high- and low-risk areas, and control movement between these areas
• Consider installing foot and hand cleaning machines at the entrances to each site. These must be maintained, ensuring that the active ingredients used are at recommended rates and have activity against ToBRFV. Alcohol hand gel has no activity against ToBRFV
• During grafting, change blades after each new tray, or more frequently, if necessary
• Use the German one knife per row, or Dutch two-knife method to ensure disinfected knives are used at all times
• Clean and disinfect all equipment with an effective, crop-safe disinfectant between each row, or use a trolley-cleaning machine
• Ensure crates are cleaned using a crop-safe disinfectant, or alternative method, e.g. low-pressure steam treatment, before they are used
• Ensure trucks are disinfected with a suitable disinfectant, e.g. Virkon S, or Menno Florades, before arrival on site and again before use
• Where water is recirculated, the sterilisation process should be checked to ensure it is sufficient to eliminate infectious ToBRFV
• Ensure all waste water enters the sewer system. Do not allow water to enter natural watercourses, which may establish ToBRFV in alternative host weed species nearby
• Ensure seed health certificates are sourced for each variety grown, especially trial varieties. Check the diagnostic tests were performed by an accredited laboratory, and that a sufficient number of seeds was tested (3,000)
• Avoid growing varieties that are extremely sensitive to ToBRFV (currently unknown)
• Monitor crops frequently for disease symptoms, be aware of typical ToBRFV patterns of infection (symptoms along rows), and if a plant looks suspicious, have it tested
• Avoid excessively stressing plants and take care to avoid unnecessary wounding which may act as an entry point for infection to occur
• Monitor weeds species on site and treat as necessary
• Clean and disinfect all site architecture using products known to eliminate ToBRFV. Ensure all products are used at their recommended rates, pressures and temperatures, and applied to maximise their effectiveness, e.g. foam

• If an outbreak is suspected, quarantine the affected house and immediately notify Defra, or appropriate plant health authority, and comply with their recommendations
• Isolate any suspicious plants and test for ToBRFV. When outbreaks are confirmed, carefully double-bag infected plants and remove them from the glasshouse, following PHSI recommendations
• Remove additional plants along the row, and plants from the rows opposite the infected plant (exact number to be removed to be taken on a case-by-case basis)
• When suspicious plants are quarantined, shut down bee hives in these areas, until a result is returned. If a positive result is returned, these hives should be destroyed
• Implement a clean-down policy based on PHSI advice and available information on disinfectant efficacy