Weeds & Invasive Plants

All Weeds & Invasive Plants Content

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.

A photo of a winter grazing pasture with a variety of grasses, shrubs and forbs that was taken at the SDSU Cottonwood Field Station that contains some field pennycress.

2025 Field Pennycress Management Considerations

Field pennycress prevalence on pastures has been observed to be in higher abundance this year in Western South Dakota. When consumed in certain quantities it can be toxic to livestock.

Many green soybean plants within a field that has brown grass and residute.

Burnt Soybeans Look a Lot Better Than Weedy Beans!

Prior to the introduction of Roundup-Ready soybean, growers were accustomed to soybeans exhibiting short-lived herbicide injury. While soybean plants may look unsightly from a PPO-inhibiting herbicide application, a more unsightly view is a soybean field full of weeds.

A green absinth wormwood plant surrounded by other green vegetation.

Absinth Wormwood Spray Window Passed: Mow now and plan to treat the regrowth in the fall

Absinth wormwood is a statewide noxious weed that inhabits cropland, pasture, rangeland, right-of-ways, and waste sites. If not effectively managed, the species can displace desirable vegetation, reduce crop yield and decrease land value.

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.

Rows of empty white, plastic pesticide containers.

2025 Pesticide Container Recycling

The South Dakota Department of Agriculture and Natural Resources is again offering pesticide container recycling services across the state. View a complete list of 2025 dates and locations.

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.

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.

Green plant with bright yellow flowers throughout.

Leafy Spurge: Do I spray now or wait until fall?

In June, leafy spurge is one of our most problematic rangeland, pasture, and roadside weeds. It is also one of South Dakota’s noxious weeds that landowners are required by law to control. So should you spray it now or wait until fall?

Examples of three commonly used protective gloves used for pesticide applications.

Pesticide Personal Protective Equipment: Glove Selection

Safety gloves are one of the most-important pieces of pesticide personal protective equipment. Glove material is very important, as not all materials provide the same protection for different pesticide ingredients.