Wheat Diseases

All Wheat Diseases Content
People stand in a field listening to a person speak

SDSU Extension programs help producers maintain healthy crops

August 26, 2025

Madalyn Shires puts on a lot of miles in the summer. As an assistant professor and SDSU Extension Plant Pathology Specialist, Shires traverses the state visiting research plots and educating crop producers on that research.

Coneflower with Aster yellows disease.

Aster Yellows Phytoplasma

Aster yellows is a phytoplasmal disease carried and introduced by aster leafhopper. It is known to infect over 80 different plant families, as the aster leafhopper has extremely broad feeding habits.

Green wheat leaves with yellow streaks throughout.

Wheat Streak Mosaic Virus Complex: Breaking the Green Bridge

As wheat harvest proceeds, it won’t be long until winter wheat planting is underway in South Dakota. To effectively reduce wheat streak mosaic virus, it is important to manage the green bridge effect to slow spread of disease in newly emerging wheat fields.

Wheat plants infected with wheat streak mosaic virus.

Volunteer Wheat and Kochia Management With Herbicides Will Likely Require Two Passes

Wheat curl mites, which carry wheat streak mosaic virus, use volunteer wheat and grass weeds as secondary hosts to infest recently planted winter wheat crops. Therefore, effective management of these plants before winter wheat planting is critical.

Green wheat plants with some yellowing throughout.

Keep Watch: Wheat Streak Mosaic Virus is Developing in South Dakota Fields

Wheat Streak Mosaic Virus has been reported in South Dakota wheat fields and is also a major wheat disease for Great Plains states in 2025. The virus is sweeping across the state and is rampant in winter wheat.

Map of South Dakota with Mesonet stations marked with blue dots.

How to Use the South Dakota Mesonet Small Grains Tool

South Dakota Mesonet Small Grains Tool is an easy-to-use and efficient tool that can help identify disease risks associated with wheat leaf rust, wheat leaf spot diseases, and Fusarium head blight.

Fusarium Risk Tool map for May 29, 2025. For a detailed description, please call SDSU Extension at 605-688-4792.

Fusarium Head Blight Update: May 29, 2025

Fusarium head blight, also known as scab, is a fungal disease that infects wheat heads during flowering. Recent weather conditions across South Dakota have provided the environment needed for Fusarium head blight to begin infection.

blades of brome grass with a brown to black, thumbnail-shaped growth on one of the blades.

Ergot: A Potential Livestock Poisoning Problem

Cool, damp weather followed by warmer temperatures favors grasses becoming infected with ergot bodies, which can cause a certain kind of poisoning that can affect cattle on pasture.

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.

Fusarium Head Blight Forecast

The warm and humid conditions prevalent in South Dakota throughout June 2024 have significantly favored Fusarium head blight disease development. As of this week, the risk for Fusarium head blight has begun to increase.

A round microscope picture of a green wheat leaf with yellow colored, stripe rust pustules throughout.

Stripe Rust Confirmed

Stripe rust has been found in winter wheat in Brookings County during recent scouting. The presence of stripe rust at this time indicates that there is potential inoculum source for this rust in our area.