12 October 2026 News
In recent years, the tomato industry has faced significant challenges from Tomato brown rugose fruit virus (ToBRFV). At the same time, discussions have emerged around the use of so-called “vaccination” or cross-protection approaches as a potential solution.
A recently published article by the Dutch National Plant Protection Organization (NVWA) has brought renewed attention to this topic. The publication emphasizes the importance of maintaining low virus pressure in greenhouse production systems and notes that practices associated with cross-protection may increase virus pressure. According to the NVWA, higher virus pressure can create conditions that accelerate virus evolution, potentially putting the longterm effectiveness of genetic resistance at risk
Research into cross-protection is based on the use of mild virus strains intended to protect plants against more aggressive variants. While this approach has been explored for other viruses, ToBRFV presents a fundamentally different risk profile. Scientists and researchers highlight that this virus is highly infectious and prone to mutation, making it extremely difficult to control or stabilize so-called “mild” strains.
The recent NVWA publication also describes genetic changes observed in ToBRFV populations exposed to high virus pressure. While further research is needed to fully understand the biological significance of these findings, the observations reinforce broader scientific concerns that increasing virus populations within production systems may create additional opportunities for virus adaptation. These findings underline the importance of strategies focused on minimizing virus pressure and limiting the spread of the virus.
As a result, there is no reliable evidence demonstrating that ToBRFV cross-protection provides consistent or safe benefits under commercial conditions. On the contrary, studies and expert
observations indicate that such approaches may:
The use of ToBRFV as a crop protection agent is not permitted in the European Union.
It is essential to recognize that not all viruses behave the same. Comparisons with other viruses, such as pepino mosaic virus (PepMV), can be misleading. Unlike these cases, ToBRFV is
considered more aggressive and less predictable, making cross-protection strategies significantly more complex and risk-prone.
At the same time, the industry has made strong progress in managing ToBRFV through proven and science-based approaches. Resistant varieties, combined with strict hygiene measures, are today the most effective way to reduce virus pressure and limit crop impact. Hygiene protects the resistance. Resistance protects the crop.
However, resistance is not immunity. Like all plant viruses, ToBRFV continues to evolve. Preserving the effectiveness of resistance therefore requires responsible and consistent practices across the entire industry.
In this context, the use of unproven cross-protection approaches introduces avoidable risks that could impact not only individual growers, but the resilience of tomato production more broadly. At Enza Zaden, we therefore strongly encourage growers and industry stakeholders to rely on validated solutions and to avoid the use of unapproved ToBRFV cross-protection methods. Protecting crops today and safeguarding resistance for the future depends on informed decisions, scientific rigor and collective responsibility. For further information, readers are encouraged to consult the NVWA publication:
For further information, readers are encouraged to consult the NVWA publication:
“What does the genetic family tree of ToBRFV tell tomato growers?”
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