Yellow rust has always been a key disease to monitor in winter wheat, but recent developments mean it deserves even closer attention this season and beyond.
A Shift in Yellow Rust Dynamics
Last season saw a significant change in the behaviour of yellow rust, with the breakdown of the widely relied-upon Yr15 resistance gene. This was driven by the emergence of a new race within the PST S10 (Warrior-) clade. Importantly, we believe this was not a new incursion from abroad, but a mutation of an existing race already present in the UK.
For growers, this has had real on-farm implications. Varieties that previously demonstrated strong early-stage resistance were unexpectedly showing signs of infection – often earlier than anticipated, in some cases even before the traditional T0 fungicide application timing.
What This Means in the Field
The key takeaway is simple: we can no longer rely on broad-spectrum yellow rust resistance at the young plant stage.
Crops that would historically have been considered “safe” from early yellow rust infection are now at risk. This means:
- Increased vigilance across all winter wheat varieties
- Earlier and more frequent crop walking
- A shift away from assumptions based purely on varietal resistance ratings
Rethinking Fungicide Strategy
In light of these changes, fungicide programmes need to be more responsive.
Rather than waiting for standard timings such as T0 or T1, the focus should be on treating yellow rust as soon as it is identified.
Practical options include:
- Early control with cost-effective curative/protectant treatments such as Triazoles + Strobilurins.
- When we reach traditional septoria timings later in the season (T1 and T2), the inclusion of yellow rust acting fungicides may be vital.
Given the potential need for repeat applications, maintaining a cost-effective approach is crucial.
Planning Ahead: Variety and Risk Management
Looking forward, variety selection and farm strategy will play an increasingly important role in managing risk.
Key recommendations include:
- Diversifying varietal portfolios rather than relying on a narrow selection
- Avoiding over-reliance on single resistance genes
- Considering variety blends, particularly where there is appetite to spread risk further (e.g. four-way blends). However, experience is showing that this may only slow the problem down rather than eliminate it
This approach helps reduce the impact of resistance breakdown and builds greater resilience into the system.
Looking to the Future
This season, the Yr15-breaking race is expected to remain dominant due to high levels of disease carryover and inoculum from last year.
However, this may not always be the case. Other races such as the “Extase” type could become more prevalent over time. The yellow rust population is constantly evolving, and management strategies must evolve with it.
Key Takeaways
- Don’t rely solely on varietal resistance – monitor crops closely
- Treat yellow rust when you see it, not just at standard timings
- Keep fungicide strategies flexible and cost-effective
- Diversify varieties and consider blends to spread risk
- Focus on proactive, preventative management rather than curative responses
Stay Ahead of Rust with Indigro
Yellow rust is evolving, and so should your approach to managing it. In a season where assumptions around resistance no longer hold, having the right advice, the right products, and the right strategy in place has never been more important.
We work closely with growers to deliver practical, field-led unbiased independent agronomy – from variety selection and crop monitoring through to tailored fungicide programmes that balance performance with cost.
If you’re seeing early rust pressure, questioning your current approach, or planning ahead for next season, get in touch with us – we’re here to help you stay one step ahead.
