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Content by Philip Rozeboom

Green alfalfa weevil larvae with a white stripe running down its body.

Alfalfa Weevil Activity Prediction Update: May 29, 2024

Most alfalfa weevil larvae that were observed this week were between the first and second instar, but it is likely that later instars are present in southern counties.

Two pictures of bright, green plants with yellow flowers.

Leafy Spurge or an Imposter?

Leafy spurge is a statewide noxious weed that can be difficult to manage. However, are the recent yellow flowers appearing throughout South Dakota landscapes leafy spurge or another species?

Various weeds emerging from a research plot in some rows, while other rows are weed-free.

Weeds Are Starting to Emerge: Even After a Preemergence Herbicide Application

During recent scouting, weeds were noticed in plots treated with preemergence herbicides. Learn some troubleshooting considerations to help determine why some weeds emerge following preemergence treatments.

Purple-brown caterpillar with orange head on a green corn leaf.

Common Stalk Borer Activity Estimate: May 24, 2024

Throughout South Dakota, common stalk borer caterpillars are still active in alternative weed and grass hosts.

A picture of a absinth wormwood plant that has white colored leaves.

Absinth Wormwood Control in the Spring

Absinth wormwood is a difficult-to-control, noxious weed that can produce great amounts of seed (50,000 seeds per-stem) and spreads only by seed, illustrating the importance of management prior to seed production.

Top: Field pennycress leaves and seeds. Bottom: Shepherd’s purse leaves and seeds.

Early Season Prevalence of Field Pennycress and Shepherd’s Purse

Many fields that are planted to winter wheat or have yet to be tilled may have a healthy infestation of field pennycress or shepherd’s purse. Learn some expert tips for identifying and managing these weeds before they become a problem this growing season.

Green beetle larvae with a white stripe running down its body.

Alfalfa Weevil Activity Prediction Update: May 16, 2024

South Dakota finally warmed up and as a result, alfalfa across the state should be scouted for alfalfa weevil larvae.

Canada thistle growing in a pasture.

Current State of Noxious Weed Management in South Dakota

Results of an online survey to determine how South Dakota stakeholders are currently managing noxious weeds.

A collection of empty pesticide and herbicide containers.

Herbicide Group Classification

The intent of providing herbicide group numbers and mode/site-of-action information on labels is to help develop herbicide plans that reduce the selection pressure on herbicide-resistant weeds. Learn how understanding this information can help improve your plans.

Green beetle larvae with a white stripe running down its body.

Alfalfa Weevil Activity Prediction Update: May 9, 2024

Although May hasn’t been extremely warm, the accumulated degree days in South Dakota since January 1, 2024, suggest that alfalfa weevil larvae could be active in several areas of the state.