Stripe rust on winter wheat has now been reported in the following counties: Cardston, Lethbridge, Lacombe, and Warner.
Additionally, there was a report of potential stripe rust in the Edmonton area and there is some evidence that stripe rust overwintered in Alberta again this year. Frequent scouting of winter wheat fields across the province is recommended.
For moderately resistant (MR) cultivars of CWRW such as AAC Gateway, AC Tempest, CDC Chase, Emerson and Moats, weekly scouting is recommended. All other cultivars are susceptible and scouting is recommended every 3 to 5 days in regions already reporting stripe rust symptoms.
A fungicide application may provide an economic return when approximately 1 plant per square metre has stripe rust symptoms. The ideal crop stage for fungicide application is at head emergence targeting the head, flag leaf and penultimate leaf. Susceptible varieties with symptoms on 1 or more plants per square meter will require a fungicide application. The MR varieties may not require a fungicide, but scouting is still necessary in case disease pressure overwhelms the resistance and becomes severe (severe symptoms would cover more than 5% of the leaf area in the upper canopy leaves).
For more information on stripe rust biology, diagnosis and control measures, visit the links below on the Alberta Agriculture website: