By: Pam de Rocquigny, Provincial Cereal Crops Specialist, Manitoba Agriculture
During the growing season, reports on the current rust situation and how it is progressing in the United States are available in the Cereal Rust Bulletins from the United States Department of Agriculture (USDA). Recently, crown rust has been reported in South Dakota and Minnesota. These reports provide growers in eastern Saskatchewan and Manitoba the opportunity to proactively scout for crown rust in their oat fields.
As a reminder, there have been changes within the crown rust pathogen populations in the eastern Prairies where virulence has developed on a number of oat varieties. Varieties that contain the Pc91 gene for resistance to crown rust, including AAC Justice, CDC Morrison, HiFi, Souris and Stainless, have been redefined for crown rust resistance in the 2016 SaskSeed Guide, 2016 Varieties of Grain Crops and Seed Manitoba 2016. The variety Summit, which is postulated to carry different resistance genes, is also losing its resistance to virulent races in the eastern Prairies; therefore, it has also been redefined for crown rust resistance.
There are a number of steps used to determine if changes are occurring within the crown rust pathogen populations, and then whether changes in variety disease resistance ratings are required. A detailed overview of this process is available CropChatter.com or in Seed Manitoba 2016.
With information from Dr. Jim Menzies, Phytopathologist, AAFC Morden & Dr. Jennifer Mitchell-Fetch, Oat Breeder, AAFC Brandon
Reprinted with permission. The original article appeared in Crop Chatter.