Albert Lea Seed House Oat Production Guide - Page 15

Stem Rust Outbreaks of this disease have not been common for about 20 years but are, once again, being reported. It is caused by the fungus Puccinia graminis f. sp. Aveanae. As a fungal disease, the risk of infection is impacted by the weather but the most important factor is having a virulent pathogen present. Symptoms Stem rust looks similar to Crown rust but there are two major differences. The first of these is the color of the pustules. Stem rust has a darker red shade, as described by the Prairie Oat Growers Association of Canada, a “brick red color.” The next is the location. Crown rust does not usually show symptoms on the stem of the plant. Stem rust will be strictly on the stem with longer darker pustules (Fig. x5). Ziesman, Barbara, Carly Huvenaars, Joseph Back, Kim Kuneff, Krista Kotylak, and Liz Simpson. Prairie Oat Growers Manual. 2010. Print. Control The most economical control for stem rust is the use of genetic resistance. Most oat varieties currently available have good genetic resistance. Fungicides can also be used for additional control. (Fungicide use will be discussed late in this section) Fig.x5. (left) Stem rust on oats, (right) a close-up of stem rust pustules on oats 15