Long-term persistence of ToBRFV in commercial greenhouse irrigation systems and challenges in virus elimination

Abstract: Tomato brown rugose fruit virus (ToBRFV) remains one of the most challenging
pathogens in tomato production due to its high persistence and efficient mechanical
transmission. This study aimed to investigate the long-term persistence of ToBRFV in
commercial greenhouse irrigation systems and to evaluate the effectiveness of sanitation
measures during crop transition. Extensive sampling was performed in 2025 at multiple
commercial tomato growers in Belgium, targeting several locations within irrigation systems.
Growers were selected based on infection history, including both active outbreaks and
greenhouses with no current infection but with a confirmed ToBRFV presence two years earlier. Results demonstrate that ToBRFV can remain detectable in irrigation systems for at least two years after an initial outbreak. Furthermore, sanitation procedures applied during crop changeover were insufficient to fully eliminate virus presence.