Submitted to: Barley Newsletter
Publication Type: Other
Publication Acceptance Date: 6/2/1999
Publication Date: N/A
Technical Abstract: Throughout most of the United States little or no barley stem rust developed in 1998. Yield loss of 0.1 was reported from stem rust in Oregon; trace losses (<0.1%) occurred in Washington, Idaho, and North Dakota. Race QCCJ, which can overcome the resistance of common barley varieties dropped to just 23% of the stem rust isolates collected from barley in 1998. The most commonly collected stem rust race was RCRS (46%) Barley leaf rust was widespread in the United States in 1998, but did not cause severe damage. Yield losses of 1.0% and 0.5% were reported for California and Wisconsin, respectively, and 0.1% losses occurred in Idaho, Kentucky, Oregon, and Washington. There were no distinct changes in frequencies of pathogenic races compared with recent years. For the past 3 years, stripe rust has been severe on barley in California, causing yield losses of 15, 20, and 15% in 1996, 1997, and 1998, respectively. Yield losses to barley stripe rust were lower, though still significant, in the Pacific Northwest, where losses ranged from 1% in Idaho to 2% in Oregon and 3% in Washington. Crown rust was found near buckthorn, the alternate host, in Minnesota, North Dakota, and South Dakota again in 1998, but spread of crown rust in barley was less than in recent years and there was no appreciable effect on yield.