Wheat Diseases

All Wheat Diseases Content
Three blades of wheat grass exhibiting Alternaria symptoms.

Secondary Wheat Diseases: Alternaria Species Detected

In wheat observed this summer, the Alternaria species, a group of secondary fungal pathogens were identified in samples collected east of the Missouri river. This pathogen is infectious on its own and can cause Alternaria leaf spot disease.

Hands holding a corn leaf with a single tar spot lesion developing.

Online Reporting of Crop Diseases for Statewide Monitoring Efforts: How You Can Get Involved

Did you know that you can become involved in disease reporting and monitoring across the state? Thanks to a new tool from the Crop Protection Network, producers, crop consultants, and homeowners can report disease sightings on a variety of crops across the state.

wheat field

Wheat

The SDSU Extension team provides unbiased, research-based information to help wheat growers make decisions to improve yields and profits.

aerial view of South Dakota farm and surrounding land

Crops

During the growing season, SDSU Extension provides weekly production recommendations.

Three wheat fields exhibiting wheat streak mosaic virus symptoms throughout.

South Dakota Wheat Streak Mosaic Virus Disease: 2026 Update

Wheat streak mosaic virus is on the move across South Dakota wheat fields. Due to the mild winter and overwintering in winter wheat, viral activity has had a jump start in 2026, and the occurrence and intensity of disease pressure is comparable to the 2025 season.

Color-coded map of South Dakota showing Fusarium head blight risk throughout the state. For a detailed description, please call SDSU Extension at 605-688-4792.

Tools Available for Fusarium Head Blight Prediction

Fusarium Head Blight (FHB), commonly known as scab, is a major disease threat for wheat each year during the flowering growth stage. To support growers in making informed fungicide decisions, forecasting tools are available that use weather data to estimate the likelihood of scab development.

Wheat plants in a field showing viral symptomology of Wheat Streak Mosaic Virus.

Wheat Streak Mosaic Virus Confirmed in 2026

At the end of April, a winter wheat sample was submitted to the Plant Diagnostic Clinic displaying typical viral symptoms of chlorosis and streaking. Upon testing, this sample was determined to be positive for Wheat Streak Mosaic Virus.

grass leaves with yellow and brown streaking on the tops and edges

Grass Diseases of South Dakota Identification Guide

Common grass disease identification guide.

a person holding a leaf that has yellow, brown and green streaking.

Bacterial Leaf Streak in Wheat Varieties Adapted to South Dakota

Research trial results for Bacterial Leaf Streak tolerance in winter and spring wheat varieties grown in a disease nursery near Volga, South Dakota.

sun rising over South Dakota field

South Dakota Pest Management Guides

The South Dakota Pest Management guides are now available for free. The guides offer recommendations for controlling weeds, insects, and diseases in a variety of South Dakota crops.