Slow and steady key to fighting disease

MORDEN, Man. — During a wet summer like this one, farmers turned en masse to fungicides and other treatments to fight crop disease.

However, researchers say the best defence is to first lay down a strong foundation of resistance and then build upon that.

So while farmers struggled to spray, bedeviled by wet soils, thick canopies and other complications, researchers at places like the Morden Research Centre plugged away at improving prairie pulse crops for another year.

To them, equipping farmers with varieties that have strong resistance to likely diseases, helps farmers get one step ahead of problems.

“Those lines will be pulled from the test,” said Agriculture Canada researcher Bob Conner, referring to pea varieties that appear to be losing genetic resistance to powdery mildew.

“There is no tolerance (from researchers for susceptibility for the disease.) If they have powdery mildew, they have to be removed from the test.”

Morden and other research centres work on hundreds of lines of pulse crops, trying to find well-yielding, hardy, disease resistant plants. They also study diseases, trying to find what makes them dangerous.

After years of ongoing development, they release new varieties as they become ready, with most new lines providing better resistance to diseases and better yields.

Peas that are immune to powdery mildew provide an example of one success story. A nearly 100 percent level of protection comes from genetic resistance bred into the main lines of the crop.

That comes from a few genes, but one, known as ER1, is the one that appears to provide almost complete control. It still works, but scientists are always watching out for a disease strain resistant to that protection.

“We have been expecting for a long time for this resistance to break down and fortunately it hasn’t happened,” said Conner.

“Nobody can tell you why. It’s a big concern that maybe one day a new (mildew) race will come around and if it does, it will be widespread.”

But in the meantime in peas, lentils, dry beans and other pulse and mainstream crops, researchers continually upgrade the disease-fighting abilities to protect them from tomorrow’s threats.

This year proved a heavy one for many diseases, but regardless, researchers pushed ahead with foundational work designed to confront future challenges.

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