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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 #181491

Title: SUNFLOWER DISEASE INCIDENCE AND DISTRIBUTION IN MIDWESTERN U.S. IN 2003

Author
item Gulya Jr, Thomas

Submitted to: Proceedings Sunflower Research Workshop
Publication Type: Proceedings
Publication Acceptance Date: 3/15/2004
Publication Date: 3/15/2004
Citation: Gulya Jr, T.J. 2004. Sunflower disease incidence and distribution in midwestern u.s. in 2003. Sunflower Research Workshop Proceedings. 26th Sunflower Research Workshop, January 14-15, 2004, Fargo, ND. Available: http://www.sunflowernsa.com/research/research-workshop/documents/Gulya_Disease_Midwest_2003_04.PDF

Interpretive Summary: Information on the geogprahic distribution and the severity of sunflower diseases is essential to collect on a regular basis. This information is used by commercial and public breeders to prioritize their breeding efforts, by chemical companies to direct their research programs for new fungicides, and to obtain emergency and full labels for fungicides. The major diseases affecting sunflower production in the Dakotas and Minnesota continue to be Sclerotinia head rot and stalk rot, while Rhizopus head rot was the most prevalent sunflower disease in the Kansas/Colorado area.

Technical Abstract: Sclerotinia head rot and stalk rot, Rhizopus head rot, Verticillium wilt and Phomopsis stem canker were the five leading diseases affecting sunflower in six Midwestern U.S. states during a fall 2003 survey, coordinated by the National Sunflower Association. Teams of trained surveyors inspected 193 fields in North Dakota (ND), South Dakota (SD), Minnesota (MN), Kansas (KS), Nebraska (NE), Colorado (CO) and Texas (TX) from the middle of August (TX) until the third week of September (ND) when sunflower fields were at physiological maturity Rust, while a notable concern on confection fields in Manitoba, was not as widespread in the U.S. survey. Downy mildew was hardly observed in the fall survey, but soil bioassays done in other studies have shown that this pathogen is widespread in the Dakotas, but disease appearance is dependent upon high rainfall following planting. Tabulation of survey results over the years will establish a baseline and timeline for the occurrence of various pests, and should help researchers decide what the most important topics to study are, and which weeds, diseases and insects are increasing, and thus need to be addressed before they become serious problems. The survey data should also help to understand the interaction between various problems (weeds, insects, diseases) and climate, agronomic and cultural factors. By having the data available on a website, this information will be of great benefit to producers, seed companies, and public and private researchers.