ARS | Publication request: EPIDEMIOLOGY OF BARLEY STRIPE RUST AND RACES OF PUCCINIA STRIIFORMIS F. SP. HORDEI: THE FIRST DECADE IN THE UNITED STATES

Submitted to: Mediteranian Cereal Rust Bulletin
Publication Type: Research Notes
Publication Acceptance Date: October 29, 2004
Publication Date: November 30, 2004
Citation: Chen, X. Epidemiology of barley stripe rust and races of puccinia striiformis f. sp. hordei: the first decade in the united states. Mediteranian Cereal Rust Bulletin. Online.

Interpretive Summary: Barley Stripe rust has been in the United States for a decade since it was first observed in Texas in 1991. The disease has been monitored using trap nurseries and field survey. Races of the pathogen have been determined every year by testing stripe rust samples from various regions on a set of barley varieties that are used to differentiate races of the pathogen. A total of 69 races have been identified in the past decade. The virulences of these races are presented. Predominant races and their distributions were summarized. Cropping and climatic factors affecting appearance of new races and predominant races were determined. An integrated control program including use of varieties with durable resistance and effective fungicides has been established. The summarized results of studies on disease epidemic, dynamics of the pathogen virulence, plant resistance, and economic effect of fungicide application on various varieties will be useful for control of the disease.

Technical Abstract: In the United States, barley stripe rust, caused by Puccinia striiformis f. sp. hordei, has spread in the south central and western United States and has caused localized damage in California and the Pacific Northwest since it was first reported in southern Texas in 1991. Barley stripe rust has been monitored using trap nurseries and field survey. Sixty-nine races of P. striiformis f. sp. hordei have been identified using a set of 12 barley genotypes. Races that were detected in California and/or Texas were also detected in the Pacific Northwest, indicating the spread of the races among the different regions and lack of selection from cultivars grown in various regions. Races with a relatively narrow virulence spectrum tended to become predominant. Major barley cultivars with non-race specific high-temperature, adult-plant resistance and the barley cropping system have played significant roles in reduction of damage by barley stripe rust.