Small Grains

All Small Grains Content

Yellow wheat with grey colored wheat heads.

Sooty Mold: A Saprophytic Fungi Observed in Wheat

While out crop scouting, sooty mold was observed in some South Dakota wheat fields. Sooty mold is a saprophyte, which can be easily mistaken for a disease caused by plant pathogens.

From left: Wheat plants killed by common root rot. Wheat plants with bleached heads due to Take-all disease. Bleached wheat heads due to stem maggot feeding.

Differentiating Between Wheat Head Diseases and Disorders

Several diseases and disorders can develop in wheat heads. Learn the symptoms of several common disease and insect issues being observed in South Dakota wheat this growing season.

Winter wheat plants at the tillering growth stage with leaves yellowing as a result of wheat streak mosaic virus infection.

Wheat Streak Mosaic Developing in Winter Wheat Fields

A few winter wheat fields in central South Dakota have been found with wheat streak mosaic disease. Incidence of this disease varied from a few plants to large portions of the field with yellowing leaves.

a strand of oats in a field

2020 Plant Disease Summaries for Small Grains

A number of field trials were implemented in the 2020 growing season with the general objective of assessing various disease management practices suitable for South Dakota growers and the Great Plains.

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.

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).

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.

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.