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Soybean Weeds

All Soybean Weeds Content

aerial view of South Dakota farm and surrounding land

Crops

During the growing season, SDSU Extension provides weekly production recommendations.

Two pictures; The left has yellow soybean plants with only brown dirt throughout. The right has yellow soybean plants with greenish weeds throughout.

Weed Management via Harvesting Order

Despite The warm and wet growing season that promoted continuous flushes of weed germination, weeds are usually present at the time of harvest. Careful consideration should be taken to determine the order of fields to be harvested.

A green Palmer amaranth weed surrounded by various other green plants.

Palmer Amaranth Confirmed in Turner County: Is this weed in your fields?

Palmer amaranth has recently been confirmed in Turner County. Currently, the estimation of Palmer amaranth infestations has been confirmed in 18 counties across South Dakota

A green field bindweed with a white flower at top.

In a Bind With Field Bindweed?

It’s August and field bindweed, one of our most-persistent perennial weeds, is flowering. Although field bindweed is not statewide noxious, it’s locally noxious in Bennett, Bon Homme, Clarke, Lake, Stanley, and Yankton counties.

Green Canada thistle with whitened leaves at the top. Various green plants throughout.

White Thistle Disease: Biological management at work

White thistle disease can be seen among many Canada thistle plants throughout South Dakota this growing season. Plants infected with the disease exhibit significant reductions in both growth and seed head compared with non-infected plants.

Two pictures of green soybeans with a blue sky in the background.

Strong, Effective Herbicide Programs Can Be Complimented With Narrow Row Spacing

While strong herbicide programs will result in effective weed management, a cultural tactic, such as row spacing can result in a complementary increase in effectiveness.

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.

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.