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Crop Management

All Crop Management Content

Red-brown colored weevil with bent antennae originating on the elongated mouthparts.

Watch for Red Sunflower Seed Weevils

In South Dakota, sunflower flowering is well underway. That means it is time to start scouting fields for red sunflower seed weevils. During the last two years, red sunflower seed weevil populations have been higher than normal with areas that exceeded the thresholds by as many as 300-500 adults per sunflower head.

Photo showing counties where soybean gall midge has been confirmed

Soybean Gall Midge Showing Up in More Counties

As the season continues, so is our soybean gall midge scouting efforts. For much of South Dakota, the soybean that are infested with soybean gall midge are asymptomatic. That is, they show limited signs of infestation, but we can still find the larvae of the soybean gall midge in the stems.

Green caterpillar with white stripe present on the side of the body. Caterpillar has three pairs of abdominal prolegs.

Green Cloverworms Causing Defoliation in Soybean

Populations of green cloverworm, a caterpillar pest of soybean, have been increasing over the last couple of weeks in South Dakota. Although green cloverworm caterpillars feed on soybean leaves, defoliation rarely results in economic loss. However, reports of increasing populations of green cloverworm and increasing amounts of defoliation suggests that scouting for this insect pest is warranted.

Corn leaf with “cigar” shaped tan to gray lesions throughout.

Northern Corn Leaf Blight Developing in Corn

Northern corn leaf blight was found in a few corn fields scouted recently. The disease was found at very low severity, except occasionally when an individual plant was found with several lesions on one leaf.

Close-up of several black caterpillars feeding on a green sunflower leaf.

Checkerspot Caterpillars in Sunflower

While scouting sunflower near Sturgis this week, we came across outbreak levels of checkerspot caterpillars that were defoliating the plants. Similar sightings have been reported throughout Western and Central South Dakota in recent weeks.

A corn field with several plants displaying long, tan to gray lesions on their leaves.

Goss’s Bacterial Blight Beginning to Show Up in Corn

Goss’s bacterial blight was found in a few corn fields scouted the week of August 5, 2019. The severity ranged from low to moderate, where at least 25 percent of the leaf area was killed by the bacteria infection on several plants. The disease is characterized by long, tan-gray lesions with wavy margins found in the center of the leaf or along the edges of the corn leaf blade.

A color-coded map of the united states indicating temperature outlook for August 2019. South Dakota is mostly covered in blue.

August 2019 Climate Outlook: Cool and Wet

According to the latest climate outlook update, odds are favoring that August 2019 will be cooler than average. The update was released by NOAA’s Climate Prediction Center on July 31, 2019.

Two diseased wheat plants side-by-side. The wheat heads on the left have ergot bodies throughout. The wheat plants on the right are infected with Fusarium head blight.

Assess Your Fields for Ergot and Fusarium Head Blight Before Harvest

The 2019 wheat harvest is well underway in South Dakota, with many acres of winter and much of the spring wheat crop left to harvest. To date, reports on yield and quality have been variable, depending on when the crop was seeded, weather conditions at important growth stages (such as flowering and grain fill) and disease pressure throughout the season.

Two corn diseases displayed side-by-side. The left corn plant has holcus spot lesions on its leaves. The right has paraquat drift injury.

Holcus Spot or Plant Injury?

Is your corn developing spots? Corn fields have been found with what appears to be Holcus spot, a bacterial disease. Upon further investigations, the leaves were found to be negative for any plant pathogens.