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Content by Connie Strunk

Left: A close-up of two wheat leaves showing light yellow streaks, a symptom of wheat streak mosaic virus. Right: Winter wheat leaves with small dark brown lesions surrounded by a yellow halo, a symptom of tan spot.

Winter Wheat Disease Update: Wheat Streak Mosaic and Tan Spot Developing at Low Level

Winter wheat fields scouted the week of May 27, 2019 in South Central South Dakota were found with wheat streak mosaic virus and tan spot developing at very low levels. Both diseases were found in non-rotated wheat fields.

Winter wheat blades with lesions with a dark brown center and yellow margin surrounding the lesion.

Diagnosing Early Diseases in Winter Wheat

Winter wheat progress is relatively behind the five-year average given the long winter season and low spring temperatures. However, it is important to scout and diagnose early-season diseases in winter wheat to determine the need for an early season fungicide.

Field with field peas and blue sky with fluffy white clouds

An identification guide of common Diseases of Dry Peas in South Dakota

A guide depicting common diseases of Dry Peas in South Dakota

A healthy, growing soybean field. Farmyard in the background.

Soybean Growers Sought for On-Farm Research Program

We want you! SDSU Extension and the South Dakota Soybean Research and Promotion Council are seeking South Dakota Soybean Growers willing to participate in a farmer-led on-farm research program.

Soybean seed drill. Courtesy: United Soybean Board

Fungicide Seed Treatment Considerations for 2019

With the excessive soil moisture and flooding that has occurred throughout South Dakota, growers may be thinking about using a fungicide seed treatment this planting season.

Diseases & Disorders teaser

Fungicide Resistance: Risk and Management

What is fungicide resistance?
Fungicide resistance can be defined as when a pathogen population is no longer sensitive or has reduced sensitivity to the fungicide that used to control the same pathogen.

A middle portion of a corn leaf enlarged to show tan-brownish lesions with dark brown wavy margins.

Bacterial Leaf Streak of Corn: A New Corn Disease in South Dakota

Bacterial leaf streak, caused by Xanthomonas vasicola pv. vasculorum (Xvv), is a recently discovered disease of corn in South Dakota. The disease was first identified in Nebraska in 2016 but now has been found in the majority of the Corn Belt states. Under favorable weather conditions bacterial leaf streak can develop to reach yield reducing levels. Like any other bacterial disease, once symptoms develop there is little that can be done to control it in the field. However, it is important to correctly diagnose this as a bacterial disease because it can be confused with gray leaf spot which is a fungal disease.

Wheat blade exhibiting brown, crusting strip rust pustules running laterally throughout the blade.

Wheat Diseases Identification Pocket Guide

Accurate plant disease identification is the first step in designing effective and sustainable disease management programs. The purpose of this guide is to provide information on how to recognize wheat diseases and also to provide possible management options.

A patch of soybeans with several plants exhibiting browning and yellowing leaves.

Plant Disease Management Decisions to Make Before Planting

For most plant diseases, in-season management choices are very limited. In fact, there are no in-season management options available for diseases caused by nematodes, viruses, and bacteria.

green leafy plants

Soybean Vein Necrosis Virus Detected in South Dakota Soybeans

A new soybean virus called Soybean vein necrosis virus (SVNV) was detected in South Dakota soybean fields in Davison and Union counties. Symptomatic plants were sporadic and found along the field borders. Infected plants showed mild to moderate severity.