Dr. Mike Harding, Alberta Agriculture and Irrigation, Brooks, AB got a call last night from Dani Kerr, an Agronomy Supervisor at Nutrien, saying that three of her staff had found stripe rust between Calgary and Drumheller.
Stripe rust was reported by Dani Kerr (Nutrien Innovation Manager) as found by three Nutrien Agronomists – Micayla Code (Rosedale), Emma Nesbitt (Balzac) and Grace Gregory (Strathmore). Some fields had only a few stripes (see photograph #1), while others had significant patches of rust (see photographs #2 and #3).
For susceptible varieties, a fungicide application is warranted when approximately one plant per square meter is rusted. Scouting for early detection is critical as once 5% of the flag leaf area becomes symptomatic in susceptible varieties it is very challenging to manage with a fungicide. A fungicide application may not be necessary for resistant varieties. Once any variety is past anthesis, a fungicide application is not likely to provide economic benefit.
For more information go to: https://open.alberta.ca/dataset/d02dd5ef-c2cf-4e7c-b020-16344057ed85/resource/58fb90bb-fafb-46e8-af3c-272bf5ce0dcc/download/agi-stripe-rust-101-2023.pdf
Growers in southern Alberta, as well as the Drumheller to Calgary region are encouraged to scout fields for symptoms of stripe rust and fungicide need. Pay particular attention to fields planted with susceptible to moderately susceptible varieties. Information on variety disease reactions can be found in the Provincial variety guides:
Given the late appearance of stripe rust in 2025 there may be questions related to crop growth stage, potential yield losses, and fungicide timing. Stripe rust appeared relatively late on the Prairies in 2024 and the PCDMN posted several updates in relation to these observations and information related to crop growth stage, potential yield losses and fungicide timing. See the following posts from 2024:
Stripe rust alert for southern Alberta, July 10, 2024
Stripe rust now in central Alberta and additional reports from Manitoba, July 12, 2024
For information on fungicide options, timings, and pre-harvest intervals consult local Provincial crop protection guides (AB Guide, SK Guide, MB Guide) and always follow label recommendations.
Photographs courtesy of Micayla Code, Emma Nesbitt and Grace Gregory, Nutrien. Symptoms of stripe rust from early July 2025, Calgary to Drumheller region.
