An unusual disease outbreak that swept across wide swaths of the Canadian chickpea crop in July has growers and agronomists scratching their heads.
“The issue went across pretty much all of Western Canada and the northern (United States). It seems to be related to some sort of stress that the chickpeas would have been under during that time or just prior,” said Sherrilyn Phelps, agronomy manager of the Saskatchewan Pulse Growers.
The area most affected is east of Swift Current and south of the Trans-Canada Highway.
The disease presented as blight and it caused severe damage to the chickpea crops Phelps examined.
CDC Orion seemed to be more affected than other varieties, which could mean its resistance to ascochyta may be breaking down.
“We saw that happen about 15 years ago when Sanford was the most popular variety, but over about a three-year period, it’s tolerance to ascochyta was broken down,” Phelps said.
“The same thing could be happening right now with the Orion.”
Ascochyta was present in some of the fields, but Phelps said the blighting caused by the disease outbreak wasn’t related to ascochyta in a lot of cases.
“Whether it was some herbicide carryover or excess moisture, things like that that could have been causing some stress at that time and it just made the crop more susceptible to the injuries or the symptoms that we’re seeing,” Phelps said.
She said there were also heavy rain, hail and wind around the time the disease started to show up.
Another stress was root rot, which seemed to be worse in areas with compaction.
“Overall, there is a number of factors and no one specific factor that seems to be consistent,” she said.
Plant samples have been sent to the Agriculture Canada centre in Swift Current to be evaluated for foliar disease and screened for fungicide resistance.
There are also chickpea and root samples being examined at the University of Saskatchewan to see what root diseases are present.
“The lab results will take some time to do because they have to get the testing set up,” Phelps said.
She said some of the affected crops have been greening up and appeared to be recovering over the past few weeks. The extent of damage the disease caused won’t be known until the chickpeas are harvested.
Growers with affected fields should continue with their disease management plans if chickpeas are green and still developing, but they should also keep in mind the appropriate preharvest intervals to use when applying fungicides.
Chickpea is the main pulse option for many growers in southern Saskatchewan so this outbreak has many growers on edge.
“It definitely is a concern especially when we’re not sure what it is and if it’s related to disease,” Phelps said.
“It was a widespread issue and hopefully over the winter we’ll have some answers for guys prior to next year.”