Ventenata Will Make You Wish For Cheatgrass

By PR Extension Office

"In a year like this, with abundant grass lasting into the fall, livestock should be satisfied," commented MSU Powder River Extension Agent Mary Rumph. "Unless, of course, the standing grass is ventenata, an unpalatable invasive annual grass that is present in some areas of Powder River County."

"Ventenata is one of those invasive grassy weeds that we may have and not know it yet," she said. "It is easily camouflaged, especially this year, by desirable grasses. One indicator to look for this Fall is patches of grass that haven't been grazed by your livestock. Please take time to investigate these areas to look for ventenata. Another indication is clumps of grass, mouthfuls of ventenata, dropped by cattle instead of consuming them."

"I witnessed this last week when moving cattle in northern Wyoming," said Rumph. "It gives 'selective' grazing a new meaning!"

Early detection and control, as with all invasive weeds, is the key to preventing large scale, economically devastating infestations. Positive identification can be made through the Extension office or Tammy Van Tine with the Powder River Weed District; unfortunatly we are becoming way too familiar with this unwanted grassy weed," said Rumph.

"Our neighbors to the south in Campbell and Sheridan counties have been focused on ventenata for the last ten years in an effort to learn how to control it," added Rumph. I'm sharing information in part from an article in the "Homeland" Fall 2022 Issue, a publication of the Tri-State Livestock News. "I thought the information is vital to any and all landowners throughout Southeastern Montana," added Rumph.

"IMAGINE" controlling invasive annual grasses by Maria Tibbetts from the University of Wyoming. Ventenata will make you wish for cheatgrass. That's the sentiment of landowners and managers who are dealing with the invasive, introduced grass. Ventenata was first identified in Wyoming – anywhere east of the Rockies, actually – less than 10 years ago, but researchers and land managers recognize the importance of control and are creating partnerships to reduce the impact of yet another invasive annual grass on the ecosystem.

The Institute for Managing Annual Grasses Invading Natural Ecosystems (IMAGINE), centered at the University of Wyoming, is taking a backward approach to research. They're gathering data from the management techniques on the ground, and correlating that, developing hypotheses and then studying further.

Brian Mealer, director of University of Wyoming's Sheridan Research and Extension Center, and the IMAGINE program, said the goal is to provide practical, effective solutions to land managers. "It helps give them some data and information on how well their management objectives are working, and moves them toward their goals for vegetation," Mealor said. "On the flip side, we have this data across a larger expanse of rangelands."

From there, they can look more closely at how the grasses may respond to herbicides, given different soil types of starting conditions, for instance.

"From the research standpoint that really sort of flips the lens," he says. "It also gives us more power to be predictive and understand patterns across the landscape, and to help landowners make decisions."

David and Terri Kane ranch near Sheridan. David is the fourth generation of his family on the ranch. One of their ranches was among the first in Wyoming to identify ventenata, in 2017, and is part of the group involved with IMAGINE. They were also one of the first to use an aerial-applied herbicide, Rejuvra, which was originally developed for cheatgrass. The herbicide is a pre-emergent, so it acts on the seeds, killing the annual grasses as they germinate. Ventenata germinates in the fall, so that's when they spray, ahead of the estimated germination date. The goal is to eliminate the seedbank, which early research suggested would take about four years. Based on what Kanes have seen on their ranch, the Rejuvra worked for about three years on ventenata.

"They were thinking they could spray in year one, and go back in year four, and maybe year 10, they'd be done. We had to go back in year three," Kane said.

That information is a huge help to managing invasive species on a larger scale, Mealor said. "This research is co-produced or co-created. It just means we are working in partnership to answer questions together. That's how our program has worked for years, but the scale and magnitude of what we're doing with those partners has dramatically changed."

The introduction of venentata and Medussahead made researchers and land managers realize how important is to to be proactive in addressing these invasive species.

Kane said they identified ventenata one year, and the next year, nearly their whole ranch was covered with the grass. The grass seeds similar to cheatgrass, but has a high silica content, making it nearly impossible for any animal – wildlife or domestic – to use for forage. "There's never a time that it's palatable for grazing," Kane said. That makes is a concern for both ranchers and public land managers for whom wildlife is the highest priority.

The information like they gathered on the Kane ranch is added to what they know about annual grasses and herbicides in general. Kane said the first year after applying the herbicide, which targets seeds only, not affecting perennial grasses and forbs, it was almost like the range had been fertilized. "It was hardy and healthy and very vigorous" he said.

Mealor said the more desirable perennials, that hold their nutrient value longer, stay green longer and are generally higher quality forage, take advantage of the extra moisture freed up by killing off the early-growing annual grasses. It not only improved the range immediately, it sets it up to be more stable and resilient during a drought. Ventenata affects rangeland to such an extent that ranchers would have to choose between controlling it with herbicides – an expensive proposition – and buying supplemental feed, Mealor said.

As Kane points out, "The cheapest land you can buy is your own. With noxious weeds, you can only bury your head in the sand for so long. Something's gotta give. They're going to dominate. Even though it's so expensive to spray, it's more cost-effective than not spraying. If you can't afford to manage the land, you probably can't afford to own it – public or private."

Those who neighbor with public lands, or who are responsible for managing public lands, are familiar with another major challenge, public perception.

"IMAGINE has had a huge hand in improving the relationships between landowners and public agencies," Kane said. "It's helping federal agencies realize and understand it is a problem and being responsible for taking care of it. It gives them the tools to help them figure our how best to manage it, and to use to educate the public about what they're doing and why."

That education and awareness is vital for slowing the spread of invasive species that don't respect property boundaries. Mealor hopes this program becomes a prototype of implementing partnerships across other natural resource management segments. "The principles and framework we're setting up, this cooperative research could be used for any natural resource issue that crosses boundaries." And not just property boundaries. "We pretty regularly communicate with folks in Montana, South Dakota, Nebraska, just trying to get people sort of rowing the boat in the right direction," he said.