Diseases & Disorders

All Diseases & Disorders Content

A wheat head showing the start of the flowering period. This growth stage is the best time to apply a fungicide to manage Fusarium head blight.

Use Fusarium Head Blight Risk Prediction Tools for Better Disease Management

Winter wheat has reached the flowering growth stage, which is a time of high risk for Fusarium head blight. By using disease prediction tools correctly, a producer can protect wheat from infection by applying a timely fungicide when the tools show moderate to high risk.

Wheat blade with strip rust symptoms.

Stripe Rust Starting To Develop in Winter Wheat

Stripe rust was found in a few winter wheat fields scouted this week. The presence of a few plants with stripe rust indicates there is inoculum of this pathogen in the state.

Wheat tillers with lower leaves covered with tan-brown lesions. The ground beneath has wheat stubble from previous wheat crop.

Scout for Tan Spot in Winter Wheat

Tan spot was observed in a few winter wheat fields scouted recently. It is important to scout winter wheat for tan spot and other early diseases developing before deciding to apply an early-season fungicide tank mixed with herbicide.

A picture of a lawn showing a ring of dark green grass in the middle of the lawn due to fungi in the soil.

Fairy Rings in Lawns

Seeing greener grass in circular pattern in your lawn? This is not due to uneven fertilizer application, but rather due to a fungi feeding on decomposing matter and releasing nitrogen in the affected areas.

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.

Left: A soybean plant with cotton white mycelia girdling the lower portions of the stem amidst healthy soybean plants. Right: A soybean field with some plants having yellowing leaves due to sudden death syndrome infection.

White Mold and Sudden Death Syndrome Starting to Develop

White mold and sudden death syndrome are starting to develop in a number of soybean fields. These two diseases develop starting at the soybean flowering growth stage and can occur throughout the rest of the soybean growing season.

Green cover crop growing within yellow wheat stubble.

Cover Crop Considerations When Dealing With Soybean Cyst Nematode

With the soybeans being harvested a little earlier than usual this year, some producers are finding themselves making management decisions that include cover crops. For soybean producers dealing with soybean cyst nematode in their fields, selection of cover crops is important since some of these can be hosts for soybean cyst nematode.

Harvested corn field with field pennycress throughout.

Soybean Cyst Nematode Management Plans Should Include Proactive Weed Management

While soybean cyst nematode can be managed through use of resistant varieties and crop rotation, presence of alternative weed hosts can negate the benefits of these practices by providing a host for soybean cyst nematode to continue to accumulate in the soil.

Left: A corn ear showing Gibberella ear rot symptoms. Right: A prematurely dried corn stalk split to reveal pith disintegration due to stalk rot.

Corn Ear Rots and Stalk Rots: The Last Issues To Check for in Corn Before Combining

Before combining corn, it is recommended to scout your field for corn ear rots and stalk rots. It is important to scout corn fields for these two issues in order to make timely decisions on corn combining.