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Wheat Diseases

All Wheat Diseases Content

aerial view of South Dakota farm and surrounding land

Pest & Crop Newsletter

SDSU Extension publishes the South Dakota Pest & Crop Newsletter to provide growers, producers, crop consultants, and others involved in crop production with timely news pertinent to management of pests, diseases, and weeds in South Dakota.

: Golden colored wheat field with much taller, golden colored, volunteer rye within.

Volunteer Winter Rye Could Be a Source of Ergot in Your Wheat

A few wheat fields scouted this summer were found with volunteer rye infested with ergot. Volunteer rye, in addition to being a weed, can be a source of ergot, which is a concern for winter wheat producers.

Small white cylindrical mites on a wheat leaf.

Wheat Streak Mosaic Virus is Prevented Before Planting Winter Wheat

Wheat streak mosaic disease (WSMD) is one of the important diseases in winter wheat and can lead to severe yield losses.

Diseases on three different wheat plants. From the left: powdery mildew, fusarium head blight, and leaf rust.

Winter Wheat Diseases Update

Powdery mildew, fusarium head blight and leaf rust were observed in a few winter wheat fields recently scouted. The recent rainfall showers and warm temperatures have favored these diseases to develop in winter wheat.

Map of South Dakota showing Fusarium head blight risk. Green indicates low risk, yellow moderate risk, and red high risk. Most of the state is green except for scattered, yellow areas within Edmunds, Faulk, Hyde, Hand, Buffalo, Jerauld, Brule, Aurora, Turner, Lincoln, McCook, Lake, Brookings, and Kingsbury counties. Some red, high risk areas are in Buffalo, Brule, Hyde, and Minnehaha counties.

Fusarium Head Blight Predicted Risk for Spring Wheat

Most of the spring wheat is at or will soon be at flowering. One disease that can develop in wheat at this growth stage is fusarium head blight (FHB or scab).

Yellow and brown streaks on a winter wheat leaf indicative of bacterial leaf streak symptoms.

Bacterial Leaf Streak Developing at Low Level in Winter Wheat

A few winter wheat fields were found with bacterial leaf streak starting to develop at low levels. Bacterial leaf streak is usually observed starting from flag leaf growth stage. It can be severe on the upper leaves when there is prolonged leaf wetness resulting from frequent rains.

Green winter wheat leaf with yellow-orange strips indicative of stripe rust.

Stripe Rust Found in Winter Wheat at Low Severity

Stripe rust was observed in the crop performance trials at the Dakota Lakes Research Farm in Hughes County and at Ideal in Tripp County. At both locations, stripe rust was at a low severity.

Map showing the risk of Fusarium head blight with green equaling no risk, yellow equaling moderate risk, and red equaling high risk. Much of the eastern half of South Dakota is red.

The Fusarium Head Blight Prediction Tool Indicates High Risk

Winter wheat is starting to flower. It is important to monitor weather conditions from when wheat is heading until flowering to decide the need for fungicide application to manage Fusarium head blight.

Three wheat plants exhibiting disease symptoms. From left: Tan spot, powdery mildew, and Barley yellow dwarf.

Winter Wheat Diseases Update: Fungal Diseases and Barley Yellow Dwarf Developing

Tan spot and powdery mildew as well as barley yellow dwarf were found developing at low levels in winter wheat fields scouted the week of May 24, 2020.

A few wheat plants showing heavy yellowing mosaic symptoms due to Wheat streak mosaic virus.

Wheat Streak Mosaic Disease Developing in Winter Wheat

Although the majority of winter wheat in the state is rated good to excellent in the recent USDA-NASS report, a few winter wheat fields in Central South Dakota have been diagnosed with wheat streak mosaic disease (WSMD) caused by wheat streak mosaic virus (WSMV).