We are still a few months away from the 2024 Prairie growing season. However, information from the Pacific Northwest (PNW) of the US does give a head's up regarding potential Prairie stripe rust risk in 2024 (https://www.wawg.org/stripe-rust-report-warmer-november-december-dont-bode-well-for-susceptible-varieties/). Dr. X. Chen with USDA-ARS and Washington State University issues stripe rust forecasts for the PNW region based on weather conditions in November and December. Unfortunately, Dr. Chen's update for January 8, 2024 indicates the risk of stripe rust for 2024 for the eastern PNW is severe and susceptible winter wheat varieties will incur average yield losses of 42% if they are not sprayed with fungicide. Fortunately, varieties with moderate to high levels of resistance will mitigate stripe rust risk and the need for fungicide. However, virulence shifts can occur so keep this in mind if you start to see more stripe rust than expected in the resistant variety you are growing. Overall, the PNW may have issues with stripe rust that could threaten Prairie winter and spring wheat crops.
Each year the PCDMN issues weekly cereal rust risk forecasts based on rust development in source locations in the USA. The PNW is mainly a concern in terms of stripe rust, while the Texas to Nebraska corridor represents a risk for leaf rust, stripe rust and stem rust, while there may be concerns related to crown rust in oat. In addition to accounting for rust development in the US, the PCDMN also looks at the number of wind trajectories that may carry rust spores from US source locations, and Prairie crop development and weather conditions.
You can keep up-to-date with Prairie cereal rust risk via PCDMN cereal rust risk forecasts that are posted to this blog from mid-May to early July each year and can be found at https://prairiecropdisease.blogspot.com/p/cereal-rust-risk-report.html.
Key management strategies for cereal rusts include host resistance, scouting and awareness of emerging rust issues, and timely fungicide application.
The PCDMN will follow up with further risk reports from Dr. Chen as we move towards the 2024 Prairie growing season.
Typical symptoms of stripe rust are as follows:
