Apr 29 2024

De-stress to reduce Ramularia risk

With a stressful start to the growing season for winter and spring crops alike, taking steps to de-stress barley crops with biostimulants, could be crucial to reduce ramularia risk this season in order to safeguard yield and quality potential.

When it comes to plant health and optimising yield and quality in barley, there is little room for error, with tillers, ear numbers and grain sites/sqm intrinsically driving yield. For this reason, close attention to detail during the growing season is crucial to optimise all components.

In barley, ramularia is triggered by stressful growing conditions early season, explains Stuart Sutherland, technical manager at Interagro. “In a year like this where growing conditions have been anything but optimal, the ramularia risk to barley crops should be considered a major threat. Ramularia can lead to significant damage on the upper leaves of the plant, reducing yield by 0.5 t/ha.”

Key Points

  • In barley, ramularia is triggered by stressful growing conditions early season.
  • Applying a biostimulant to reduce these stress factors, can all help mitigate the triggers for the disease.
  • Of the products tested, Zonda was the most effective.
  • Spring barley responds particularly well, with applications optimal at T1 and T1.5.

Ramularia risks and symptoms

The problem is, the disease grows symptomless until flowering when the stress of flowering marks a change in the barley’s metabolism, which is also a trigger for the disease. “It is only at flowering when growers may start to see the disease symptoms which appear as lesions on the upper leaves of the plant, continues Stuart.

Environmental stresses such as waterlogging, high light intensity and drought can all exacerbate the disease. “Applying a biostimulant to reduce these stress factors, can all help mitigate the triggers for the disease,” says Stuart.

Continuous barley and drought-prone soils are also the perfect storm for creating a stressful plant that is at risk of ramularia.

De-stress to reduce ramularia risk

De-stress to reduce ramularia risk

De-stressing barley with biostimulants

It is for this reason, biostimulants are being employed by the A&R Fraser family in Dorset, supported by their Agrii agronomist Todd Jex.

“Specifically, we’re using biostimulants to manage the ramularia, as well as the lodging threat in our barley crops,” explains Todd. “The evolution of fungicide resistance in ramularia to the main single-site fungicides has enhanced the need to find another approach to managing the disease.

“At flowering, the plant begins to mobilise assimilates to the developing grain and essentially gives up on its own natural defences as it shifts its resources into ensuring the next generation.”

The farm’s use of biostimulants began five years ago when we conducted non-scientific farm trials, followed by two years of tramline trials, explains Todd. “With a wide range of soil types on the farm, we were in a good position to be able to evaluate product performance.

“Of the products tested, Zonda was the most effective. Agrii also screened hundreds of biostimulants and found a lot of inconsistency, with Zonda proving to be one of the better ones in terms of ROI,” he says.

Zonda is an amino acid and peptide biostimulant from Interagro, designed to help crops reach their genetic yield potential and reduce the impact of abiotic stress by improving plant health. “Feeding a crop Zonda guarantees the supply of amino acids for building protein, critical for plant health,” explains Interagro’s Stuart Sutherland.

De-stress to reduce ramularia risk

Ramularia reductions with Zonda

Todd’s approach has been to apply Zonda early, using 1 l/ha at T1.5 before there has been any sign of ramularia leaf spotting. “In the first year of tramline trials on continuous spring barley we had a yield response of 0.15t/ha over the weighbridge. In 2018, the uplift was 0.28t/ha in a spring barley crop following winter wheat. In 2019, we had an uplift of 0.1 t/ha and 0.4t/ha, a margin over input cost of £7/ha and £58/ha respectively.

Biostimulants act in many different ways, including signalling to cells to help the plant ward off disease. To get this ‘elicitor effect’ then you have to go early, explains Todd. “We found spring barley responds particularly well, with applications optimal at T1 and T1.5. Any later is too late, as the crop starts to get stressed, increasing the ramularia risk. But the benefits have been really quite visual in droughty years.”

Agrii trials have also shown Zonda applications to be beneficial alongside PGRs, reducing the stress to the crop, and also benefitting lodging control, he adds.

More information and suppliers

If you require technical support, or wish to discuss how Zonda may be able to benefit your own situation, please contact Stuart below.

Zonda is available to purchase through Agrii.

Get in touch

Require technical assistance or product information? Please get in touch with our Technical Manager, Stuart Sutherland.

For all other general enquiries, please email or call us at the office. If you’d prefer, drop us a message using our contact form and we’ll get back to you as soon as possible.

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