Crop & Pest Report

Accessibility


| Share

Sunflower Rust Update (08/06/20)

Sunflower rust is being found in North Dakota and growers are encouraged to scout for the disease.

Sunflower rust is being found in North Dakota and growers are encouraged to scout for the disease. Free moisture (dews, fog, etc) and moderate to warm temperatures favor disease development. Sunflower rust is visible as small cinnamon-brown pustules filled with dusty spores. Rust primarily occurs on leaves, but can appear on petioles, stem and bracts of heavily infected plants (Figure 1). If 1% rust severity is identified on the upper four fully expanded leaves at or before bloom (R5 growth stages), a fungicide application is warranted.  Fungicide applications after bloom are not recommended. For disease severity diagrams and additional information on sunflower rust, please visit our previous article in the July 30th article of the Crop and Pest Report.

 ppth.5

 

Sam Markell

Extension Plant Pathologist, Broad-leaf Crops

 

Brandt Berghuis

Graduate Research Assistant and Ph.D. Student

NDSU Plant Pathology

This site is supported in part by the Crop Protection and Pest Management Program [grant no. 2017-70006-27144/accession 1013592] from the USDA National Institute of Food and Agriculture. Any opinions, findings, conclusions, or recommendations expressed are those of the website author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.

USDA logo

Creative Commons License
Feel free to use and share this content, but please do so under the conditions of our Creative Commons license and our Rules for Use. Thanks.