Protect canola yield against sclerotinia

Known as the most destructive canola disease in Canada, sclerotinia stem rot, or white mould can cause yield losses as high as 50%.

The best defense against sclerotinia and protecting yield loss is preventative fungicide applications. While fungicides are protective and effective against this critical disease, the variability of sclerotinia can make scheduling routine spraying a challenge.

Does it pay to spray?

Determining if or when a fungicide application will protect a field against sclerotinia is difficult and can change from field to field. Here’s a comprehensive tool to help assess the risk of sclerotinia developing in a field.

In recent years, many canola-growing areas have experienced drier-than-normal conditions, leading growers to assume there is low to no disease pressure in their canola crop. A critical and detailed assessment of risk factors in your field should be completed, even under seemingly low-pressure conditions so you don’t lose yield potential.

Syngenta Technical Lead Carolyn Wilson shares this example of a Manitoba field in 2023 that experienced dryer growing conditions. “Upon initial assessment, one could be led to believe sclerotinia pressure was low,” explains Wilson. “However the grower saw a positive response to the application of Miravis^® Bold versus the untreated check in this field, with an average yield increase of 12.5 bu/ac across two replicates over the untreated checks. It’s clear in this example, it paid to spray,” she adds.

Selecting the right product:

Growers have been dealing with yield and crop quality losses from sclerotinia for years, with few available fungicides to tackle the disease. Today, a growing number of products are available, complete with multiple active combinations to control the disease and manage resistance, though these products are still reliant on the Group 3 class of fungicides.

Evaluating the right product for your canola acres requires careful consideration of active ingredients and the level of activity of the active ingredients on your target pathogen – sclerotinia.

Common fungicide products used in 2023 to manage sclerotinia

DYK: In 2023, approximately 80% of the canola acres treated with a fungicide after first flower were treated with a product that contained a Group 3 class fungicide.
Source: AgData 2023 Fungicide Report

Miravis^® Star provides two high-performing active ingredients – ADEPIDYN^® and fludioxonil – that provide long-lasting, systemic protection against sclerotinia. These two effective modes of action provide built-in resistance management as the only canola fungicide on the market containing a Group 7 and Group 12.

To learn about what makes the ADEPIDYN^® molecule effective against a number of pathogens, visit this ADEPIDYN^® page.

Timing matters:

The objective of applying a sclerotinia fungicide is to cover petals and penetrate into the canopy to help protect potential infection sites. The optimal timing to apply a sclerotinia fungicide is 20-30% bloom.

However, as we know there are often circumstances where it’s difficult to apply at the optimal timing across the farm, which leads to some applications being later than ideal. Miravis^® Star, with its wide application window between 10 – 50% flowering offers an earlier start to protect more canola acres and yield, giving growers flexibility so they can optimise this important application.

Sclerotinia won’t wait – be prepared for in-season applications to reduce the risk of yield and quality loss by protecting canola acres with the right fungicide. Remember, choosing a fungicide with a combination of active ingredients, application window flexibility and product effectiveness are a grower’s best option.

Always read and follow label directions. ADEPIDYN^®, Miravis^® and the Syngenta logo are trademarks of a Syngenta Group Company.