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ARS Home » Plains Area » Fargo, North Dakota » Edward T. Schafer Agricultural Research Center » Sunflower and Plant Biology Research » Research » Publications at this Location » Publication #93679
Title: CENTRAL GREAT PLAINS SUNFLOWER RUST SITUATION IN 1996: RACE IDENTIFICATIONAND HYBRID EVALUATION FOR RESISTANCE

Author
item Gulya Jr, Thomas
item LEE, R - UNIV UTAH, SALT LAKE CITY
item JARDINE, D - KANSAS STATE UNIVERSITY
item SCHWARTZ, H - COLORADO STATE UNIV.

Submitted to: Proceedings Sunflower Research Workshop
Publication Type: Proceedings
Publication Acceptance Date: 1/20/1997
Publication Date: N/A
Citation: N/A

Interpretive Summary: The Central Great Plains area of western Kansas, eastern Colorado, and southwestern Nebraska now produces about 25% of the US sunflower production. The climate of this area is much different from that of the Dakotas, and thus the diseases affecting sunflower are different. Sunflower rust, which exists as many different strains or races, has become a problem again as the weather in the Midwest enters another wet cycle. Since sunflower rust is generally controlled by resistant hybrids (and not fungicides), it is important to know what rust strains are present so that plant breeders can select genes to control specific races. A total of 18 different races of sunflower rust were identified from samples collected in 1996. Significantly, races which were predominant in the 1970's no longer exist. Similarly, most of the oilseed and all of the confection hybrids are susceptible to the new mix of races. Plant breeders need to be aware of the "shift" in rust races, and to incorporate resistance to the new races into current hybrids.

Technical Abstract: The U.S. sunflower rust race situation in the 1970's was predominated by races 1 and 2, and with the differentials available then, only four races could be identified. Now with the aid of nine differentials, over 500 races can be distinguished. With increasing sunflower production in the central U.S., it is important to monitor diseases in both the Dakotas and the area of western Kansas and eastern Colorado. Rust samples collected in 1996 revealed the presence of 18 rust races, with four races comprising nearly half the isolates. Most of the oilseed and all of the confection hybrids are susceptible to these new races. Thus, plant breeders should use these new races to select rust-resistant parents as they attempt to create new rust-resistant hybrids.