|Steffenson, Brian - NORTH DAKOTA STATE UNIV|
|Fetch, Tom - NORTH DAKOTA STATE UNIV|
|Casper, David - FORMER ARS EMPLOYEE|
Submitted to: Barley Newsletter
Publication Type: Other
Publication Acceptance Date: June 20, 2000
Publication Date: N/A
Technical Abstract: Barley stem rust was more common in 1999 than in 1997 or 1998, but yield losses were minimal except in SD (2%) and ND (0.5%). Race QCCJ, which is virulent on all common barley varieties, increased in frequency from 23% of isolates from barley in 1998 to 83% in 1999. The increased presence of QCCJ after 3 years indicates a new source of inoculum, probably in susceptible winter wheat cultivars in TX or OK. Barley leaf rust was light in 1999 except in NC where it caused 6% yield loss. As in recent years, virulence to Rph1, 2, 4, 8, and 11 was common, but virulence to Rph 5, 9, or 12 was rare. Virulence to Rph7, which had not been found in the U.S. since 1990, was common in MD, OH, and VA in 1999. For the past 4 years, stripe rust has been severe on barley in CA, causing yield losses of 15, 20, 15, and 16% in 1996, 1997, 1998, and 1999, respectively. Losses in ID, OR, and WA were minimal in 1999. Crown rust was common on barley near buckthorn in ND and SD but did not spread widely into fields of barley.