WESTI Ag Days: Annual conference offers current information on weed management in Wyoming

University of Wyoming (UW) Extension hosted its WESTI Ag Day conference at the Washakie Museum and Cultural Center in Worland from Feb. 3-4.

The annual conference aims to provide professional farmers with current, research-based information about best practices in Wyoming agriculture.

Discussion topics ranged from weed management and plant disease to fungicide resistance and pesticide application, with a specific emphasis on current issues affecting Wyoming farmers.

Weed management

Jeremiah Vardiman, assistant coordinator of UW Extensionʼs Pesticide Safety Education Program (PSEP), kicked off the conference with a presentation on Palmer amaranth in the Big Horn Basin.

In his role, Vardiman collaborates with the Wyoming Department of Agriculture, UW Extension educators and other industry leaders while overseeing private and commercial pesticide licensing exams, providing study materials and facilitating educational opportunities to fulfill program requirements.

Based in Powell, Vardiman has also led the Palmer Amaranth Working Group since the weed was first discovered in the Big Horn Basin in 2023. 

The group is dedicated to monitoring and studying the plant in order to mitigate chances of widespread establishment.

Palmer amaranth

Palmer amaranth is an invasive plant with a notorious reputation for being difficult to manage. 

UW Extension explains Palmer amaranth is particularly dangerous to row crops and crops emerging later in the growing season, and Vardiman says dry beans and sugarbeets are most vulnerable. 

Palmer amaranth chokes out crops and can act as a host for insect pests. In dry conditions, UW Extension further notes the weed can generate high levels of nitrates which can be toxic to livestock.

Palmer amaranth was relatively rare in Wyoming until recent years, but Vardiman notes the weed is currently spreading along several main highway routes and county roads.

“We haven’t necessarily seen it in crop fields, but it’s spreading,” Vardiman said. “We want to be diligent and aware and keep track of where it’s going.”

Vardiman admitted exact details on where the plant came from and why it’s spreading are still being studied by the working group.

One theory says the seeds could be spreading from gravel and sand pits during road construction, but whatever the cause, Vardiman emphasizes proactive management is crucial. 

Slowing the spread

In his presentation, Vardiman gave tips on identifying Palmer amaranth and how to report it, as well as some management options to help slow the spread including herbicides and rotational planting.

He noted Palmer amaranth germinates quickly, and the best chance to stop the weed is to kill it before it comes out of the ground. 

Vardiman further noted Palmer amaranth is capable of developing herbicide resistance relatively quickly, so an informed application program and other preventative measures are key.

He encouraged planters to get in touch with chemical dealers and local Extension resources before applying any herbicides, as premature or unnecessary application can aid resistance and make management even more difficult.

In addition, Vardiman noted crop rotation is an extremely important management option for suppressing potential growth in the off season.

“Corn, small grains and forages are our best options for control,” Vardiman emphasized. “These plants are competitive against annual plants, and we also have more herbicide options in these crops than we do with dry beans and sugarbeets.”

Additional highlights

In addition to presentations, WESTI Ag Days featured a vendor reception highlighting ag businesses from the farming sector.

Vendors displayed products ranging from seeds and sprayers to drone and irrigation system technology.

In addition, a complimentary lunch sponsored by ANB Bank was provided on opening day, and drawings for door prizes donated by various sponsors took place throughout the event.

WESTI Ag Days wrapped up on Feb. 4 following an all-day private applicator class on pesticide application held at the Washakie Museum and Cultural Center.

Grace Skavdahl is the editor of the Wyoming Livestock Roundup. Send comments on this article to roundup@wylr.net.