By Treena Lake, Summer Student and Barb Ziesman, AAg, Provincial Plant Disease Specialist
Stripe rust symptoms on wheat leaves. (photo
courtesy of R. Aboukhaddour, AAFC)It’s that time of year again! You should be scouting your cereal crops for signs of stripe rust. Look for elongated yellow to orange pustules on leaves; the pustules will often extend the entire length of the leaf blade.
Stripe rust is an old, but economically relevant, disease. The disease causes leaf lesions, reduces photosynthetic area, slows crop growth and can negatively impact crop yield and quality.
Stripe rust inoculum from infected wheat in the United States is capable of traveling on wind currents and settling in the Canadian prairie region. In the United States, levels of stripe rust have been lower this spring compared to last year. However, increased moisture in some regions could allow for further disease development and more inoculum potential if favourable wind currents occur. So far, the low number of reverse wind trajectories from the south, combined with the cool, dry conditions in the prairies, may lend a hand in reducing disease pressure this growing season.
Stripe rust may appear after spores blow in from infected wheat in the Pacific Northwest or central Midwest regions of the United States.
To ensure your cereal crops are protected, scout your fields for disease symptoms and apply fungicides when appropriate. The presence of symptoms should be confirmed prior to making fungicide application decisions. As part of the decision-making process, monitor the progression of the disease symptoms and take into account the wheat variety. Some cultivars have a greater resistance to stripe rust than others. Resistance ratings can be found in the Varieties of Grain Crops or SaskSeed Guide.
This year, pathology specialists are working together on the Prairie Crop Disease Monitoring Network (PCDMN) to keep the public informed about cereal rust conditions across the prairies. Visit the Prairie Pest Monitoring Network Blog for weekly reports on disease pressure, wind trajectories and cereal rust risk.
If you see stripe rust in your fields, please contact the Ministry’s Provincial Plant Disease Specialist (Barb Ziesman: 306-787-4671 or barbara.ziesman@gov.sk.ca) or your regional Crop Extension Specialists so we can keep everyone posted on disease incidences this season.