Rust Diseases of Wheat

Leaf, stem, and stripe rust comprise the three rust diseases of wheat. In the central Great Plains of North America, leaf rust is the most common of the three diseases. Since 2000, stripe rust has increasingly become more common and widespread in Nebraska and other Great Plains states. Stem rust is detected only at trace levels in the central Great Plains because most hard red and hard white winter wheat cultivars grown in the region are resistant to the disease. However, a new race of stem rust known as Ug99 that overcomes the resistance in wheat cultivars grown in the United States and other parts of the world was detected in East Africa in 1998. At least seven races of the Ug99 lineage are now known and have spread to various countries in Africa and the Middle East. Should these stem rust races arrive in the U.S., there will be potential for significant yield losses due to stem rust.