The third 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: May 20-26, 2025 report
General weather and crop conditions
- Prairie winter wheat crops are generally in the tillering to stem elongation growth stages, while much of the spring wheat crop has been seeded or will be shortly and are generally in the seedling stage
- Temperatures have been somewhat higher than normal for most of the Prairie region since April 1, 2025, and from May 20-26, 2025 temperatures have ranged from around 5 to 15.2oC
- These temperatures are generally not conducive to rust development, although cooler temperatures are more conducive for stripe versus leaf and stem rust
- Growing season rainfall for the Prairie region has been generally drier than normal
- Recent rainfall in some areas the Prairies could potentially have washed rust spores from the air and into wheat crops, especially winter wheat, while also resulting in canopy moisture conditions that may favour infection and further rust development
Pacific Northwest (PNW)
- There were increased numbers of reverse wind trajectories that passed over the PNW region and into the Prairies from May 20-26 versus May 13-19, 2025
- Although, stripe rust development continues, it is generally lower versus 2024; however, further development may occur over the next several weeks
- Overall, as of May 26, 2025 the risk of stripe rust appearance from the PNW is generally limited and scouting for this disease in the Prairie region is generally not urgent
- However, there were 19 locations, mainly in Alberta, the BC Peace region and in western Saskatchewan that had an elevated number of trajectories
- Although the current stripe rust situation in the PNW is limited, Prairie farmers in these areas that are growing susceptible varieties may want to consider keeping an eye out for stripe rust symptoms as they visit fields for weed scouting and crop inspection activities
Total number of dates with reverse trajectories originating from the Pacific Northwest region of the USA that have crossed the prairies between May 20-26, 2025
Texas/Oklahoma
- There were no reverse wind trajectories that passed over the TX/OK region and into the prairies from May 20-26, 2025
- Development of stripe and leaf rust of wheat are continuing, although levels are generally low.
- Texas and Oklahoma winter wheat crops are mostly headed and into the grain filling stages, while as of May 25, 2025, 17% and 3% of the Texas and Oklahoma winter wheat crops have been harvested
- As crops mature over the next 2-4 weeks, they will no longer represent an important source of uredospores which only develop on green living non-senesced plant tissues
- Texas and Oklahoma winter wheat crops are mostly headed and into the grain filling stages, while as of May 25, 2025, 17% and 3% of the Texas and Oklahoma winter wheat crops have been harvested
- Overall, as of May 26, 2025 the risk of stem, leaf, stripe, and crown rust appearance from the Texas-Oklahoma corridor is limited and scouting for these diseases in the Prairie region is not urgent
Kansas/Nebraska
- There were only five Prairie locations that had wind trajectory events from the KS/NE region from May 20-26, 2025
- Overall, as of May 26, 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
- Until recently there have been limited reports of cereal rust in the Kansas/Nebraska region
- However, continuing rust (mainly stripe rust) observations and development in KS/NE will increase the risk
- Recently stripe rust has been reported in more Kansas counties, while stripe rust was noted for the first time in several Nebraska counties as of May 23 and 29, 2025
- From May 20-26, 2025, there were five locations in Alberta and Saskatchewan that had an elevated number of trajectories
- MEDICINE HAT and PROVOST, AB, and KINDERSLEY, NORTH BATTLEFORD, and UNITY, SK
- Although the current rust situation in the KS/NE region is limited, Prairie farmers in these areas that are growing susceptible varieties may want to consider keeping an eye out for rust symptoms as they visit fields for weed scouting and crop inspection activities.
