Barley yellow rust in North America

Yellow rust of barley is an invasive disease that was found in the past 10 years in North America. The causal agent, Puccinia striiformis f. sp. horde i, was introduced into Colombia, South America, from Europe in 1975. It spr ead to all major barley-producing areas in South America by 1982. In 1988 i t was found in Mexico and in 1991 in Texas. Since then it has been found in all major barley-producing areas of the American West. Originally describe d as race (R) 24, barley yellow rust in North America is now known to be a very heterogeneous population. Resistance has been identified, evaluated, a nd is being introduced into commercial malting and other barley cultivars. Cultural and chemical controls are effective and available. An integrated a pproach using general field resistance and other tactics is described for s ustainable management of barley yellow rust.