Dr. Denis Gaudet at AAFC-Lethbrige, and his crew, surveyed fourteen winter wheat and 22 spring wheat fields were surveyed for stripe rust in the Lethbridge, Warner, Taber, Forty Mile and Cypress counties of southern Alberta. Regular thunder showers and cool evening temperatures have provided good infection conditions for development of stripe rust.
However, stripe rust development continues to progress slowly. Spraying with fungicides is widespread which is aiding in curtailing the epidemic. In general, stripe rust remains well established although patchy in winter wheat in the above counties with observed average severities of less than 5% and the highest at 35%. In spring wheat fields, average stripe rust levels remain at trace levels with the highest severity of 10%. Winter wheat and most spring wheat fields are beyond the developmental stage permissible for spraying. Unless the environmental conditions change drastically, yield and quality losses will be minor in winter wheat and negligible in spring wheat.
Weekly surveys for stripe rust will continue until the end of the growing season.
Producers should be considering winter wheat options for this fall. Radiant is susceptible to stripe rust and should be replaced with newer, stripe rust resistant varieties. For traditional dryland regions in western Canada, the variety Moats is a good choice. For irrigated production and in parkland regions, Flourish or AAC Gateway are recommended. All three have stripe rust resistance and exhibit similar levels of winter hardiness.
Plant Pathologist, AARD