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Content by Philip Rozeboom

United States Environmental Protection Agency Sign plate outside the agency’s main office.

EPA Proposes a Decision to Approve Registration for Dicamba Labeling to Be Applied to Tolerant Soybean

Dicamba products previously labeled for overtop application to tolerant soybean are not registered for use during the 2025 growing season. However, the EPA has proposed to re-register these dicamba products for use in tolerant soybean starting in 2026.

Top: Green cloverworm caterpillar. Bottom: Cabbage looper caterpillar.

Green Caterpillars Causing Defoliation in Soybean

This week we observed several species of caterpillars in soybean fields. The most common species were the green cloverworm and the cabbage looper.

Small, green teardrop shaped insects on a green, soybean stem with pink flower.

Soybean Aphids Detected in South Dakota

While scouting soybean aphids this week we observed small colonies of 5 to 10 soybean aphid nymphs. This indicates that the soybean aphids are just starting to arrive in South Dakota soybeans and weekly scouting for them should be occurring.

Corn and soybean fields with abundant weeds growing throughout.

Inexpensive and Simple Herbicide Programs in Corn and Soybean Will Not Be Effective

While selecting an inexpensive program with only one active ingredient in each application may be tempting due to the current agricultural economy, the result will likely be a more expensive problem in the future.

U.S. Environmental Protection Agency offices in Washington, D.C.

Update on Chlorpyrifos Use in South Dakota

As of June 30, 2025, the labeled uses for chlorpyrifos products for food and feed are limited to alfalfa, soybean, and wheat in South Dakota. Chlorpyrifos can no longer be used to treat sunflowers.

Cream colored larvae on white and green soybean stem on brown dirt.

Dectes Stem Borer Adults Detected in South Dakota Soybean

Dectes stem borer adults have been collected from soybean in Southeastern South Dakota this week. As a reminder, the larvae of insect pest are capable of reducing soybean yields from 0-17% due to its feeding activity inside of the main stem.

Green waterhemp plant next to a black, ink pen. Green soybeans in the background with brown soil in the foreground.

Waterhemp is flowering. No seeds present yet.

Waterhemp is one of the most-difficult weeds to manage in South Dakota row crops. While herbicide resistance is a great factor in the difficulty of managing this weed, the biology of the species plays an important role as well.

Blue container with lid visible that has a label indicating it is only for pesticide contaminated clothing/PPE.

How to Properly Launder Pesticide Contaminated Clothing

Many types of personal protective equipment are intended for single use only and should be discarded after use, but how do you wash reusable equipment and clothing contaminated with pesticide residue?

Left: Kochia growing abundantly in an untreated soybean field. Right: Kochia weeds burned down in a soybean field managed with an herbicide mixture.

Glufosinate + lactofen is likely an effective mixture to manage kochia postemergence in soybean

Kochia is a difficult to manage weed that infests crops across South Dakota. Mixing effective herbicides is a tactic that can reduce selection pressure on resistant weeds and increase the effectiveness of weed management.

Gray beetle with long antennae.

Dectes Stem Borer in South Dakota Soybeans

Fact sheet on Dectes stem borer in South Dakota soybeans