This year’s unusually wet summer has created conditions that increase the risk of seedling blights and bunt for UK growers, with Microdochium and Fusarium infections posing a significant threat.

Additionally, the prevalence of ergot is likely to persist into next year, making effective crop protection and management more critical than ever.

Technical Manager, David Leaper gives advice and guidance on the subject, to ensure you’re equipped with the right knowledge and tools to minimise these risks and safeguard your crops.

Higher Risk of Seedling Blights Following Wet Summer

Understanding the Risk: Why is Seedling Blight a Concern?

The mild and wet conditions of early and mid-summer have created the perfect environment for pathogens like Microdochium and Fusarium to thrive. This increases the likelihood of seedling blights and related diseases such as bunt affecting your autumn-sown crops. 

Alongside this, the increased presence of ergot is also a major concern. While ergot isn’t strictly a seed-borne disease, the sclerotia can be carried on seed, posing a significant threat to crop health and yield in the following year.

Testing is Key

We strongly recommend testing your seed to identify the level of inoculum present. This will give you a clear picture of the seed’s health status and help determine the most effective seed treatment strategy. 

Best Seed Treatments for Minimising Disease Risk

Using a suitable seed treatment is essential to reduce the risk of both seed- and soil-borne diseases. Here are some of the treatments we recommend:

- Beret Gold (fludioxonil)
- Redigo Pro (prothioconazole + tebuconazole)
- Vibrance Duo (fludioxonil + sedaxane)

These fungicidal treatments are proven to protect against a range of diseases, ensuring your seedlings get off to a strong, healthy start.

Managing the Threat of Ergot

Ergot is likely to remain a problem into next season, especially with the popularity of low- or no-tillage systems and the presence of secondary hosts like black-grass and other flowering grasses. Agrii’s Technical Manager, David Leaper, advises growers to consider cultural measures alongside chemical controls to minimise the risk.

“Ergot pieces have a relatively short life remaining viable in the soil for just one season, so the sowing of a non-cereal crop, cultivating to a depth of at least 5cm and good control of grassweeds will all reduce the inoculum reservoir available to infect crops,”

Recommended Cultural Measures for Ergot Control

1. Non-Cereal Crop Rotation: Ergot pieces have a short viability period in soil (typically one season), so rotating with a non-cereal crop can disrupt the cycle.
2. Cultivate to a Depth of 5cm: This burial technique can reduce the surface presence of sclerotia.
3. Effective Grassweed Control: Black-grass and other grasses in field margins serve as hosts for ergot. Keeping these weeds in check is crucial.

Our Commitment to Higher Seed Standards

Although industry standards permit two ergot pieces in certified wheat, barley, and oat seed, and 12 pieces in hybrid barley and rye, Agrii adheres to even higher standards. Our Master Seeds brand limits ergot pieces to just one in wheat and two in hybrid barley, reducing the risk and ensuring peace of mind.

The Impact of Seasonal Conditions and Tillage Practices

The return of seedling blights as a significant threat is catching many growers off guard, but these diseases have never really gone away. Bunt, for example, can escalate from minimal levels to complete crop failure in as little as three to four seasons if left unchecked.

Factors Increasing Seedling Blight Risk:

- Late Drilling: Late-autumn drilling, often used to control problem weeds, leads to crops being drilled into wet and cold seedbeds. This increases the risk of seedling blights and other diseases.
- Reduced Tillage Systems: These practices leave more crop residues on the surface, providing a breeding ground for pathogens.

Seed Treatments for Late Drilling

When drilling later in the season, consider using seed treatments with nutritional or biological properties that stimulate early growth. This will help your seedlings establish more quickly, reducing the risk of disease taking hold.

Optimising Plant Populations for Better Black-Grass Control

Agrii’s trials at our heavy land R&D site in Stow Longa have identified the ideal plant population for effective black-grass control:

- 300-350 plants/m² is the optimum population for black-grass competition by Christmas.
  
However, there’s a trade-off: delaying drilling until early November can reduce establishment rates by 12% to 32%, depending on seed rate and treatment used.

Seed Treatment Comparison: Vibrance Duo vs Beret Gold

In trials, seed treated with Vibrance Duo consistently showed higher establishment rates compared to Beret Gold. While Vibrance Duo is slightly more expensive (£4/ha), it delivered a 6% increase in spring plant populations and a 0.1 t/ha yield improvement on average.

Seedling Nutrition: Bridging the Hunger Gap

Once the seedling has exhausted the nutrient reserves of the seed, it enters a ‘hunger gap’ before it can access soil nutrients. During this period, the right seed treatments can make a huge difference.

Choosing the Right Nutritional Seed Treatments

Products like i-Man (manganese) and Zax (zinc) have been shown to deliver significant yield uplifts in our trials. While they are often considered optional, we’ve seen that combining these with standard treatments like Vibrance Duo can lead to even better results.

Making the Right Seed Treatment Choices

The market is flooded with products making nutrient and bio-stimulant claims, but only a few deliver consistent results. In our trials, the combination of Vibrance Duo with i-Man has consistently outperformed standalone treatments.

Protect Your Crops This Autumn

With the risk of seedling blights and ergot on the rise, now is the time to take action. Ensure you’re using the best seed treatments, implementing effective cultural measures, and keeping an eye on your seed’s health status. At Agrii, we’re here to support you with expert advice and high-quality seed options tailored to your needs.

For more guidance on seed treatments and crop management, get in touch with our team or explore our range of Agrii Master Seeds for the highest quality and peace of mind.