Stripe rust has been found in some winter wheat crops in the Alberta counties of Cardston, Lethbridge, Lacombe and Warner.
Alberta Agriculture plant pathologist Mike Harding confirmed the existence of the fungal disease in southern Alberta today.
There may also be stripe rust in the Edmonton area, but that is not yet confirmed.
Harding said in an interview last week that weather conditions have been ideal for the development of stripe rust, and he recommended frequent scouting of fields.
The disease has already been a factor in parts of Montana, where crop experts have recommended spraying in many cases.
Winter wheat varieties that are moderately resistant to stripe rust — AAC Gateway, AC Tempest, CDC Chase, Emerson and Moats — should be checked weekly.
Susceptible varieties in areas where the disease has already been found should be checked every three to five days, Harding said in a news release.
“A fungicide application may provide an economic return when approximately one plant per sq. metre has stripe rust symptoms,” he said.
“The ideal crop stage for fungicide application is at head emergence targeting the head, flag leaf and penultimate leaf. Susceptible varieties with symptoms on one or more plants per sq. metre will require a fungicide application.”