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Crop Express - September 2026: Sudden Death Syndrome in SOybeans, Corn Disease and Biocontrol Field Notes

Writer: Larry Fiene
Larry Fiene
1 day ago
2 min read

Aerial view of test site at Planet Earth Agronomy in Black Earth Wisconsin

Five updates from the field this edition: a watermelon crop in South Texas, Sudden Death Syndrome in Midwest soybeans, corn disease pressure across the Great Lakes region, our soybean disease trials, and how biocontrol is holding up on our potatoes and watermelons.


Jump to any section below.


Sudden Death Syndrome in Soybeans Hits the Midwest


Sudden Death Syndrome (SDS) is showing up in many soybean fields this season. In the photos below, each flag marks a plant showing SDS symptoms. Compare the Big Bean-treated soybeans with the untreated soybeans, then the side-by-side view, with Big Bean on the left. The biostimulant treatment helped plants avoid premature death.


Big bean treated soybeans flag represents sudden death syndrome soybean plants.

Big Bean Treated Soybeans

Flags represent SDS plants

Sudden death syndrome untreated soybeans

Untreated Soybeans

Flags represent SDS plants

SDS untreated soybeans

Side by Side Soybeans

Big Bean Treated on the left


Texas Watermelons on Healthy Soil at Prukop Farms


The Prukop watermelon farm in South Texas is using biology and biostimulants to improve soil and plant health.


Here's how this season's crop progressed:

Prukop watermelon, August 1st planting

August 1st

Planting

4-6 inches

Prukop watermelon, August 14th, stretching

August 14th

Stretching

1-2 feet

Prukop watermelon, August 30, setting fruit

August 30th

Setting Fruit

6-10 Feet


Corn Diseases Rear Their Ugly Heads


Close-up of two ears of corn in pale green husks on a black background, highlighting the golden kernels and fresh texture

Corn fields across the Great Lakes region are showing Goss's wilt, gray leaf spot and northern corn leaf blight, along with nitrogen deficiency in some fields.


Goss' wilt on corn leaf.
Goss' Wilt
Gray leaf spot on corn leaf
Gray Leaf Spot
Nitrogen deficiency, northern corn leaf blight
Nitrogen Deficiency Northern Corn Leaf Blight

There's some good news. A few diseases are not as bad in our area as last year, including anthracnose leaf spot, eyespot and southern rust.

Anthracnose Leaf Spot
Anthracnose Leaf Spot
Eyespot
Eyespot
Southern Rust
Southern Rust

Corn Stunt Disease


Corn stunt is spread by leafhoppers. It's caused by a bacterial spiroplasma, so it does not respond to fungicides.


Close-up of corn plants in a field, with green leaves streaked red and a silking ear at bottom right.
Close-up of green corn plants in a field, with some leaves showing pink and yellow striping on the stalks.

Close-up of a corn plant leaf with pink and purple streaks in a green field, showing a damaged or diseased seedling.


Timing matters:

Five dried corn cobs infected with corn stunt spiroplasma disease arranged on a dark background
Early-Season Infections of corn stunt spiroplasma disease can lead to poor pollination and poor yields.

Later infections, in July or August, have a smaller impact on yield.



Our Soybean Disease Trials Are Still Looking Good


No white mold or Sudden Death Syndrome has been detected in our soybean disease trials so far this season


Hand parting soybean plants with green pods hanging among dense leaves in a field.
Soybean Trial Pods
Green soybean field in the foreground beside corn rows, with rolling wooded hills and a cloudy sky in the background.
Soybean Canopy
PEA team recording trial data for soybeans and take notes at a field table under a blue sky.
PEA Team Collecting Soybean Trial Data

Biocontrol Holding on Our Potatoes and Watermelons


Our potatoes and watermelons show no disease symptoms. Both crops are being grown with biological fungicides this year.


Potato plant with green leaves and small purple-yellow flowers growing in bare soil, viewed close up outdoors.
Biocontrol Potatoes

Striped watermelon growing on a vine in a leafy garden bed with dark soil and green leaves
Biocontrol Watermelon

A large green watermelon grows on the vine in a garden bed, surrounded by sprawling leaves and dark soil.
Biocontrol Watermelon


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