ToBRFV resistance and the importance of balance

Tomato Brown Rugose Fruit Virus (ToBRFV) has reshaped tomato production worldwide. First identified in Israel and Jordan in 2014, the virus spread rapidly across key growing regions. As of 2025, it is no longer classified as a quarantine pest in the European Union. The conversation has therefore shifted from containment to long-term resilience.

In this article, Arushi Badola, Global Crop Manager Tomato Fresh & High Tech at BASF | Nunhems, shares her perspective on how ToBRFV has influenced tomato breeding and why resistance, while important, is only one part of the solution.

Resistance as foundation – not the full solution

When ToBRFV first appeared, developing resistant varieties became an urgent priority. Growers needed reliable genetic solutions to protect their crops and reduce uncertainty.

At BASF | Nunhems, breeding efforts were quickly accelerated to identify and develop resistant material. But one principle remained clear: resistance alone does not make a successful tomato variety.

It is also important to underline that resistance does not equal immunity. Resistant varieties significantly reduce virus impact and help maintain performance under pressure, but they do not prevent infection entirely. Good hygiene protocols and preventive measures therefore remain essential parts of responsible crop management.

A variety must perform as a complete package. If a plant tolerates the virus but compromises yield, fruit firmness, flavor, shelf life, or overall plant vigor, it does not offer a sustainable solution. For growers, performance is measured in consistent output, marketable quality, and economic return.

That is why resistance is integrated into high-performing genetic backgrounds. The goal is not to trade performance for protection, but to combine both.

Durable resistance through gene stacking

Identifying resistance is only the first step. The next challenge is durability. Viruses evolve, and resistance based on a single genetic source is bound to break.

To address this, BASF | Nunhems applies multiple gene stacking strategy. Resistance sources, often taken from wild tomato relatives, are combined within a single variety. By using different resistance mechanisms together, the risk of a virus overcoming the plant’s defenses is greatly reduced.

This layered approach provides broader, more robust protection and helps maintain stable performance even when virus pressure persists.

Validation in real-world conditions

Controlled tests are only the beginning. Extensive global trials evaluate varieties under different climates, systems and management practices. For this reason, BASF | Nunhems runs extensive global trial programs. Every year the new pipeline is evaluated in real field conditions. Not only for ToBRFV pressure, but also yield, stability, fruit quality and overall plant balance.

Close collaboration with growers is an essential part of this process. Early feedback and market acceptance help refine selection decisions. At the same time, transparent communication about resistance levels and performance ensures that growers can make informed and realistic choices.

Being prepared for evolving virus pressure

Even in regions with low or no virus pressure, preparedness is essential. ToBRFV has shown it can spread quickly.

Therefore, testing resistant varieties in regions with low or no virus pressure is essential. This allows growers to gain experience with the material and be ready to respond when pressure increases.

Balance as the guiding principle

ToBRFV has reinforced a key lesson in tomato breeding: long-term success depends on balance.

Resistance is essential, but it must be combined with strong yield potential, consistent fruit quality, and reliable agronomic performance. At BASF | Nunhems, this integrated approach guides breeding decisions and long-term research investments.

Building resilience is not about focusing on a single trait. It is about ensuring that every component of a variety works together, delivering protection, performance, and profitability for growers today and in the future.