The nineth weekly Prairie Crop Disease Monitoring Network (PCDMN) Prairie wind trajectory cereal rust risk report for 2025 is available for download now at the following link: July 1-7, 2025.
Crop development and weather
- Prairie winter wheat crops are generally moving into the grain filling growth stages, while much of the spring wheat crop is moving out of flag leaf emergence into head emergence and flowering
- Temperatures have been somewhat higher than normal for most of the Prairie region since April 1, 2025, and from June 30-July 6, 2025 temperatures ranged from around 11 to 21.8°C. These temperatures are generally not conducive to leaf and stem rust development, although cooler temperatures are more conducive for stripe rust
- Growing season rainfall for the Prairie region has been variable with some areas below or above normal. Recent rainfall in some areas the Prairies could potentially have washed rust spores from the air and into wheat crops, while also resulting in canopy moisture conditions that may favour infection and further rust development
Pacific Northwest and Montana
- There were low-moderate reverse wind trajectories that passed over the PNW region and into the prairies from July 1-7, 2025. Stripe rust development, especially in commercial winter wheat fields is generally lower versus 2024. Overall, as of July 7, 2025 the risk of stripe rust appearance from the PNW is generally low and scouting for this disease in the Prairie region is generally not urgent
- Nonetheless, Prairie locations with three or more trajectories may be at higher risk. The late development and low levels of stripe rust in commercial PNW fields has had an overall dampening effect on the rust risk from the PNW
- The recent detection of stripe rust in research plots at multiple locations in Montana brings the stripe rust issue adjacent to the Prairie region
- These observations bring the stripe rust problem much closer to southern Alberta and southern Saskatchewan and could represent a regional source of this disease
- There were a moderate number of trajectories that passed over Montana and into the Prairie region from July 1-7, 2025
- Overall, as of July 7, 2025 the risk of Montana acting as a source of stripe rust for Prairie region is generally low given observations of stripe rust have been in research trial plots. However, further stripe rust development in commercial Montana wheat fields could increase the risk for Prairie producers
Kansas-Nebraska corridor
- There was a low number of wind trajectory events from the KS/NE region for July 1-7, 2025. Overall, as of July 7, 2025 the risk of stem, leaf, stripe, and crown rust appearance from the Kansas-Nebraska corridor is limited and scouting for these diseases in the Prairies is not urgent
- Dry conditions and the progress of winter wheat crop towards maturity and harvest will reduce the risk from the KS/NE region. However, the detection of stripe rust in research plots earlier this summer in Wisconsin brings the stripe rust issue closer to the Prairie region
Regional reports of stripe rust on the Prairies
- During the first week of July there were multiple reports of stripe rust in Alberta, including in the Calgary to Drumheller region, as well as in the Airdrie region. Levels have been mainly low, although patches of increased levels were observed in some fields
- https://prairiecropdisease.com/2025/07/04/first-observations-of-stripe-rust-in-commercial-fields-in-alberta/
- Dani Kerr, Micayla Code, Emma Nesbitt, and Grace Gregory, Nutrien agronomists
- Rebecca Wiebe, Agronomy Manager with Core-Ag, Carstairs, AB and Core-Ag colleagues Candice Kerr and Jill McCambly
- In their most recent update as of July 14 and 15, 2025, Dani Kerr, Nutrien indicated that stripe rust symptoms have been observed in the Penhold and Bentley areas of central Alberta, while also receiving a report from a grower in the Rimbey region
- Last week, there were further reports of stripe rust at low levels in multiple fields in the Madden to Airdrie area of Alberta. In addition, Dr. Mike Harding and colleagues, AAI Brooks, observed stripe rust in a field around Nanton, AB
- Rebecca Wiebe, Agronomy Manager with Core-Ag, Carstairs, AB and Core-Ag colleagues Candice Kerr and Jill McCambly
- Craig Shand, Chinook Agronomics Inc., Co-owner/operator Shand Farms Ltd. and Travis Hunter, Field Agronomist Chinook Agronomics Inc. (Photos 1 and 2)
- Additional reports of stripe rust in fields in the Bruderheim and Taber (Photos 3 and 4, observation made last week) areas of Alberta
- Christine MacTaggart, Richardson Pioneer, Lamont, AB and Dana Maxwell, President & CEO, Director of Plant Genetics Services, Ag-Quest Inc.
- Update July 16, 2025: Dani Kerr and Tom Chapman with Nutrien let the PCDMN know that there have been additional detections of stripe rust in several fields in Lacombe County (near Sylvan Lake) and one in Ponoka County, as well as three fields in the Claresholm and Nanton areas (M.D. of Willow Creek).
- Wheat producers in the following Alberta regions should be on the look out for stripe rust development (Update July 16, 2025)
- Calgary to Drumheller
- Airdrie and Madden
- Taber
- Nanton and Claresholm
- Penhold, Rimbey, Bentley, Sylvan Lake, Ponoka
- Bruderheim
- From June 17-23 and 24-30, 2025 there were elevated numbers of wind trajectories from the Pacific Northwest for regions where recent stripe rust observations were made
- E.g. Beiseker, Calgary, Lethbridge, Vulcan, Lacombe, Edmonton, Olds
- June 17-23, 2025 PCDMN rust risk update and June 24-30, 2025 PCDMN rust risk update
- Scouting for stripe rust is especially critical for wheat fields planted to susceptible and 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.
Photo 1. Stripe rust symptoms in a field in the Madden area of Alberta, July 2025. Photo courtesy Travis Hunter, Field Agronomist Chinook Agronomics Inc.
Photo 2. Stripe rust symptoms in a field in the Madden area of Alberta, July 2025. Photo courtesy Travis Hunter, Field Agronomist Chinook Agronomics Inc.
Photo 3. Stripe rust symptoms from the Taber area of Alberta, July 2025. Photo courtesy Dana Maxwell, President & CEO, Director of Plant Genetics Services, Ag-Quest.
Photo 4. Stripe rust symptoms from the Taber area of Alberta, July 2025. Photo courtesy Dana Maxwell, President & CEO, Director of Plant Genetics Services, Ag-Quest.