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The winter can be an excellent time to review disease issues you encountered in previous growing seasons and then use this information to plan for future seasons. For the cereals rusts one can also start to look at info coming from the USA in terms of the developing situation.
Dr. Xianming Chen (WSU) just released the first outlook for the 2021 growing season in relation to stripe rust risk in the Pacific Northwest (PNW). Dr. Chen uses forecast models to indicate potential yield losses for susceptible wheat varieties in the upcoming growing season.
For 2012 & the PNW he is indicating a forecasted average yield loss of 39% for highly susceptible wheat varieties. This would be in the absence of using fungicide in-crop. Dr. Chen will be following up with another forecast in March which will include all of the winter weather.
Here is the link for Dr. Chen's rust risk report for 2021 and the PNW.
https://www.wawg.org/moderate-levels-of-stripe-rust-forecast-in-first-report-of-2021/
https://www.wawg.org/moderate-levels-of-stripe-rust-forecast-in-first-report-of-2021/
You may be asking why should I be worried about the stripe rust situation in the PNW or the leaf and stripe rust situation in Texas/Oklahoma. Unfortunately, spores produced by the various cereal rust pathogens are adapted to long-distance transport via wind currents.
Parcels of air can pass over areas in the USA that are experiencing rust epidemics. These air parcels can pick up rust spores and then move them into the Prairie region from the PNW and the Texas to Nebraska corridor.
During the spring & summer these wind parcels can move over rust source areas in the USA and pass over Prairie locations within as little as half a day to 3-5 days. Unfortunately, given the pigmented and thick-walled nature of rust spores they can readily survive this flight.
Here are some examples of average travel time in days for backward trajectory events originating from the PNW and Nebraska/Kansas and traveling to various locations in western Canada, June 16 to 30, 2009.
For the last two growing seasons the Prairie Crop Disease Monitoring Network (PCDMN) has been producing cereal rust risk maps for the Prairie region. These are based on: 1) the extent and severity of rust development in source areas in the USA; cont'd.
2) the occurrence and frequency of wind parcels that can move rust spores from rust source areas in the USA and into the Prairie region; 3) Prairie weather conditions; and 4) the stage of Prairie crop development.
These reports are posted on the PCDMN Blog at: https://prairiecropdisease.blogspot.com/p/cereal-rust-risk-report.html as well as on the PCDMN twitter feed ( @pcdmn). You can find an PCDMN overview of cereal rust risk in relation to wind trajectories at this link: https://drive.google.com/file/d/19Lb1z3WTF3x2bdn2GkOCewdVjHi44JjH/view
The PCDMN blog also has a variety of information related to disease identification and crop scouting for disease issues. This information can be found at: https://prairiecropdisease.blogspot.com/p/scouting-tips-calendar.html. Here are some examples of the info available:
Did you know that you can subscribe to the PCDMN Blog so that you will be instantly notified of any PCDMN posts and reports. Instructions for signing up can be found at: https://prairiecropdisease.blogspot.com/2020/07/subscribe-to-pcdmn-blog.html. There is no cost to you.
