|STEFFENSON, BRIAN - NORTH DAKOTA STATE UNIV
|JIN, YUE - SOUTH DAKOTA STATE UNIV
Submitted to: Barley Newsletter
Publication Type: Other
Publication Acceptance Date: 3/1/1996
Publication Date: N/A
Technical Abstract: Barley stem rust, caused by Puccinia graminis f. sp. tritici was more severe in 1995 than in the previous 5 years. Overall, yield losses were light, but late planted fields in NE North Dakota and NW Minnesota suffered significant loss. Race Pgt-QCCJ comprised 89% of the stem rust isolates from barley in the U.S. in 1995. Barley leaf rust, caused by Puccinia hordei, was widespread in the U.S. in 1995 causing heaviest yield losses of 5% in North Carolina and 1% in California. Leaf rust is rarely a problem in the central U.S. and significant losses to leaf rust did not occur in the upper Midwest in 1995 although leaf rust severity there was greater than in the previous 5 years. In 1995, 21 different races of P. hordei were collected, which is the largest number of races reported over the past 7 year's surveys. No isolates of P. hordei with virulence to barley with the resistance gene Rph7 were found in 1995, although such isolates were identified in the 1994 survey. Barley stripe rust, which first entered the U.S. from Mexico in 1991, became firmly established throughout the Pacific Northwest in 1995. Stripe rust caused barley yield losses of 1% in Oregon and 1.5% in California in 1995. Stripe rust is particularly well adapted to the mild winters and cool summers of the Pacific Northwest, so it can be expected to increase in importance. Crown rust of barley, a newly discovered form the P. coronata, was found associated with buckthorn bushes, its alternate host, in North Dakota, South Dakota, and Minnesota. As yet, crown rust has not become widespread enough to cause significant damage. There were no measurable losses in barley yield to crown rust in 1995.