Content by Connie Tande

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.

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.

Aerial view of the SDSU Northeast Research Farm.
Jul 23

Northeast Research Farm Tour

Attend the annual Northeast Research Farm Tour on Thursday, July 23, 2026, from 4:00 p.m. CDT to dusk at the Northeast Research Farm (15710 455th Ave. South Shore, SD 57263). The farm is located on the junction of State Highway 20 and Codington County Highway 11, or 2.5 miles west of Exit 193 on I-29.

close up of a broccoli leaf with blackrot.

Black Rot of Brassica Crops

Overview and management of Black Rot for Brassica Crops.

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.

External and internal ring rot symptoms on two potato samples.

Bacterial Ring Rot: Yet another devastating disease of potato

Ring rot is primarily a disease of stored tubers and seed potatoes, where it produces black or brown lines just below the surface of the potato.

Two broccoli plants exhibiting early black rot symptoms.

Black Rot of Brassica Crops

Black rot is an uncommon, but devastating bacterial disease in South Dakota that can develop during extended periods of hot and wet weather, leading to rapid and widespread crop loss.

Dried corn growing in a field with visible damage and molding.

Mycotoxins: Should you be concerned?

Environmental stress caused by the weather or damaged crops increases the potential for mold and mycotoxin development. Learn some answers to common questions about mycotoxins and how to manage them.