Uploaded August 2026 | Updated September 2026, 2 weeks ago
Fungicide resistance is a growing concern around the world, but Canadian growers still have an opportunity to stay ahead of it by learning from regions where resistance is already well established.
Speaking at Bayer Crop Science's Fungicide Resistance Workshop at Guelph, Ont., Bayer global fungicide lead Dr. Andreas Mehl says Canada's relatively low fungicide use in row crops has helped keep resistance pressure lower than in many parts of Europe.
Mehl explains that resistance develops more quickly in regions where crops receive multiple fungicide applications each season. In Europe, high-yielding production systems often require more intensive fungicide programs, increasing the selection pressure that favours resistant pathogen populations. In Canada, where corn, cereals, and canola typically receive one or two fungicide applications, growers remain in a much stronger position.
That doesn't mean resistance can be ignored. Mehl stresses that fungicides remain critical tools for protecting yield, but their long-term effectiveness depends on using them wisely.
"Fungicide resistance can be managed," he says. "Growers don't necessarily need to be afraid... with the right advice, you don't have a loss of yield if you use the right products."
One of the most important strategies is avoiding repeated applications of solo products. Instead, Mehl recommends using fungicide mixtures with multiple modes of action to reduce the selection pressure on any single chemistry and help preserve product performance over time.
Not all fungicide groups carry the same resistance risk. Based on decades of experience in Europe, Mehl says QoI (Group 11) fungicides, commonly known as strobilurins, have proven the most vulnerable to resistance. SDHI (Group 7) fungicides present an intermediate risk, while DMI (Group 3) fungicides have generally shown the greatest stability. That makes balanced product mixtures and sound resistance management programs increasingly important.
Beyond product choice, Mehl encourages growers, agronomists, researchers, and industry representatives to share information and monitor resistance trends together. Regular surveillance, trusted agronomic advice, and open communication can help identify emerging issues before they become widespread.
Perhaps the most important message is that resistance itself is a natural biological process. Fungicides do not create new mutations; they simply select for naturally occurring mutations that already exist within pathogen populations. Understanding how those mutations affect fungicide performance is the key to managing them successfully.
"We just need to know what are the properties of this mutation to manage it in the right way," he says.
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#agronomy #farming #agriculture #fungicide
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Fungicide resistance is a growing concern around the world, but Canadian growers still have an opportunity to stay ahead of it by learning from regions where resistance is already well established.
Speaking at Bayer Crop Science's Fungicide Resistance Workshop at Guelph, Ont., Bayer global fungicide lead Dr. Andreas Mehl says Canada's relatively low fungicide use in row crops has helped keep resistance pressure lower than in many parts of Europe.
Mehl explains that resistance develops more quickly in regions where crops receive multiple fungicide applications each season. In Europe, high-yielding production systems often require more intensive fungicide programs, increasing the selection pressure that favours resistant pathogen populations. In Canada, where corn, cereals, and canola typically receive one or two fungicide applications, growers remain in a much stronger position.
That doesn't mean resistance can be ignored. Mehl stresses that fungicides remain critical tools for protecting yield, but their long-term effectiveness depends on using them wisely.
"Fungicide resistance can be managed," he says. "Growers don't necessarily need to be afraid... with the right advice, you don't have a loss of yield if you use the right products."
One of the most important strategies is avoiding repeated applications of solo products. Instead, Mehl recommends using fungicide mixtures with multiple modes of action to reduce the selection pressure on any single chemistry and help preserve product performance over time.
Not all fungicide groups carry the same resistance risk. Based on decades of experience in Europe, Mehl says QoI (Group 11) fungicides, commonly known as strobilurins, have proven the most vulnerable to resistance. SDHI (Group 7) fungicides present an intermediate risk, while DMI (Group 3) fungicides have generally shown the greatest stability. That makes balanced product mixtures and sound resistance management programs increasingly important.
Beyond product choice, Mehl encourages growers, agronomists, researchers, and industry representatives to share information and monitor resistance trends together. Regular surveillance, trusted agronomic advice, and open communication can help identify emerging issues before they become widespread.
Perhaps the most important message is that resistance itself is a natural biological process. Fungicides do not create new mutations; they simply select for naturally occurring mutations that already exist within pathogen populations. Understanding how those mutations affect fungicide performance is the key to managing them successfully.
"We just need to know what are the properties of this mutation to manage it in the right way," he says.
Website: realagriculture.com
#agronomy #farming #agriculture #fungicide
Find us on our other social media platforms:
X/Twitter: twitter.com/realagriculture
Instagram: instagram.com/realagriculture
Facebook: facebook.com/realagmedia
