Sunflower Pathology
Project Directors: Samuel Markell, North Dakota State University

Approximately 85-90 percent of the 2 million acres of sunflower planted annually in the U.S. are in the North Central region. According to the National Sunflower Association, diseases are the most significant biological yield-limiting factor for sunflower production. Despite this, few pathologists work on sunflower and limited reference and Extension literature on sunflower diseases exist. Consequently, disease identification is challenging for growers and limited IPM recommendations has resulted in a reliance on fungicides that are sometimes not effective for disease management.

Project Updates

In 2020, the Sunflower Pathology Working Group made the most of virtual meetings to expand membership across both state and national borders. Team members come from multiple states and even Australia. The focus for the year was on updating sunflower production guides in the Dakotas, developing materials for diagnosticians though the American Phytopathological Society, and updating the National Sunflower Association’s disease section on the Association’s website.

The Workgroup’s collaborative efforts have supported research into sunflower diseases as well. Team members from South Dakota State University, North Dakota State University and the University of Nebraska collaborated to test fungicides on Phomopsis stem canker to reduce disease severity and minimize yield loss. The National Sunflower Association published an excellent summary to share details about the trials, including results about which fungicides were most effective and factors that may impact the fungicide’s success.

Looking forward to 2021, the Sunflower Pathology Working Group is working to develop a diagnostic series on nutrient and abiotic disorders of sunflower. This pocket-sized and field-hardy publication builds on the success of the Sunflower Disease Diagnostic Series which describes 20 diseases of sunflower in the United States. This series was developed to help farmers and consultants identify sunflower diseases in the field, with support from the National Sunflower Association, South Dakota Oilseeds Council, NCIPMC (USDA), NDSU Extension, SDSU Extension, and UNL Extension. The Worgroup also plans to publish a plant health diagnostic guide on head diseases and will update and administer evaluation instruments to determine future objectives.