Weeds & Invasive Plants

All Weeds & Invasive Plants Content

Volunteer corn plants scattered throughout a soybean field.

Grazing Corn Stalks to Combat Volunteer Corn Following Drought Periods

The incidence of volunteer corn in subsequent crops tends to be greater following periods of drought. Utilizing livestock to graze corn residue following harvest is a strategic management practice to reduce volunteer corn in the following crop.

Collection of susceptible and resistant kochia plants in sample pots demonstrating herbicide effectiveness.

Mixing it Up: Fall Herbicide Mixtures for Kochia Management

Fall-applied residual herbicides can help manage early emerging weeds, such as kochia, by using snowmelt and early spring rainfall as activating precipitation to move the herbicide into the soil layer of emerging weed seedlings.

Absinth wormwood, biennial thistle rosette, and leafy spurge.

Recent Rainfall Likely to Improve Fall Herbicide Applications for Noxious Weed Management

Under hot and dry conditions, weeds are stressed and herbicide activity decreases, leading to poor management. While recent rain events have impeded row crop harvest, the moisture is welcomed to improve the activity of fall herbicide performance for noxious weeds in pastures and rangelands.

SD Sundog growing within a series of crop performance testing plots.

Utilizing Cool-Season Crops for Weed Management

For producers facing increasing challenges from herbicide-resistant Palmer amaranth or waterhemp, incorporating a cool-season crop can provide another tool for diversifying weed management.

A small spotted spurge weed in a lawn and a fully-grown mat of spotted spurge on a driveway.

A Surge in Spurge

Spotted spurge is a common, drought-tolerant weed known for its prostrate growth pattern, meaning it grows lying flat on the ground. This is one of the most-difficult weeds to control in lawns, gardens, and landscaping.

What is Velvetleaf?

Velvetleaf is a large weed with soft leaves that’s normally associated with corn and soybean fields. However, we’re hearing more gardeners and specialty crop growers reporting its presence.

A group of green plants with white seed heads amongst green grass.

Avoid Noxious Weeds When Haying Right-Of-Way Ditches

After June 15 or July 10 (dependent on location), right-of-way ditches can be mowed or hayed as announced by the South Dakota Department of Transportation. While there is a demand for grass hay, care should be taken when haying right-of-way ditches.

Testing Center on the South Dakota State University campus.

SDSU Extension Pesticide Applicator Testing Locations

Whether you are interested in becoming certified as a private or commercial pesticide applicator, SDSU Extension is proud to offer in-person pesticide applicator testing locations throughout South Dakota.

Sunflowers blooming in a South Dakota Field.

Sunflower Production: Late-Season Weed Escapes Should Guide Future Weed Management Plans

Many sunflower fields across the state are far enough along in their development that the window for preventing weeds with residual herbicides has passed. Weed escapes that remain in the field through the remainder of the growing season can contribute seed back to the soil seedbank.

Green soybeans plants with a light grey background. All soybean plants have purple flowers which indicates the plants have reached reproductive stage 1.

Soybean Plants Are Entering the Reproductive Stage (R1): Last chance to spray select herbicides

The summer solstice roughly marks the date when soybean plants switch from vegetative growth to reproductive growth. An important aspect of the reproductive growth stage is that many herbicides can no longer be applied after plants reach any bloom stage.