ELM CREEK, Man. – A race of stem rust new to the Prairies is poised to present problems for oat growers.
Known as NA67, the race has become the most prevalent stem rust in Saskatchewan and Manitoba fields, says Tom Fetch, a cereal plant pathologist at Agriculture Canada’s Cereal Research Centre in Winnipeg. All oat varieties are susceptible to it.
NA67 was found in almost half of the 300 samples taken at locations in Saskatchewan and Manitoba in 2002. Last year, evidence of the stem rust was found at two-thirds of the sites sampled.
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That presents the potential for the disease to flare under favourable conditions, said Fetch, who presented his views during a meeting of the Prairie Oat Growers Association in Elm Creek Feb. 4.
He estimates NA67 caused about $10 million in damages to Manitoba and Saskatchewan oat crops in 2002. The economic losses last year were minimal. That may have been because the winds that carry the spores up from the southern United States were not as prevalent as usual.
After it infects an oat plant, NA67 encircles the stem and cuts off the movement of water. The damage makes oat crops susceptible to lodging.
The spores of the fungus usually arrive from the United States in late June or early July. The threat is greatest in eastern Saskatchewan and in Manitoba.
Fetch said Agriculture Canada researchers have lines in their breeding program with resistance to NA67. However, it will still be years before those lines become registered and commercially available to growers.
In the meantime, he advises oat growers to plant the crop early so it will be past the point of greatest vulnerability to infection when the spores arrive from the U.S. He also advises growers to consider stem rust resistance when deciding what varieties to plant.
Fungicides are an option. Tilt is registered for crown rust in oats and will also provide protection against stem rust.
