From Emily Lockard
Cheatgrass (Bromus tectorum) has gained notoriety in the west, with concern about Japanese brome (Bromus japonicus) trialing behind. The new invasive kid in town is ventenata (Ventenata dubia) which hails from Southern Europe, Western Asia and Northern Africa.
While its spread is not as vast in Montana yet (it has found its way to parts of Gallatin County), it has been known in other states to bully cheatgrass and take over. A great solution for our cheatgrass problem? Not so fast. Cheatgrass (native to Eurasia), Japanese brome (also native to Eurasia) and ventenata are all winter annual grasses. This means, like winter wheat, they germinate in the fall and are ready when the snow melts to start growing. Where desirable grasses do not have a good foothold, this allows for invasive species like Cheatgrass, Japanese brome and ventenata to take advantage of the lack of competition. These grasses take up soil moisture and nutrients that all plants are competing for, but because of their ability to start growing earlier in the spring they can take over before other grasses have a chance to compete. Cheatgrass and Japanese brome have their own unique role in a changing fire regime and cheatgrass is a perpetual problem in winter cropping systems, especially those that don’t have rotations to counter the cheatgrass growth cycle. Why is ventenata coming to play? Like other invasive species, it takes advantage of disturbed, bare ground and plant communities that are struggling to compete because they are overgrazed or struggling from drought. Other states experiencing an influx of ventenata have found it can be even more invasive than cheatgrass. Not a great sign. What should you do if you suspect any of these grasses are on your property? First, proper identification is key to control. Early spring identification can be difficult with any grass, but especially ventenata, so identifying during the summer will make identification easier and possibly more accurate. When you have identified the undesirable winter annual grasses, flag them off or mark the area with GPS points so it is easy to identify where they are in early spring. Your local Agriculture Agent can assist with identification. Back to why ventenata isn’t the cure for land covered by cheatgrass.
While Cheatgrass is palatable to grazing livestock in the early spring and fall before plants turn purplish brown to prevent seed production, it doesn’t appear that ventenata is very palatable. High levels of silica prevent it from being a desirable grass for grazing animals, but there is some evidence it may be palatable early in spring. More research on this is needed. Other control options are limited for ventenata due to a lack of research in this newly spreading grass. Other states have found that Imazapic applied in the fall to semi-dormant perennial grass stands has been effective. Imazapic applied in the fall followed by an application of nitrogen fertilized can help perennial grasses recover from herbicide damage and be more competitive. According to a study in Washington, a spring application of Imazapic is more effective than a fall application. Make sure to read the label and follow directions, the label is the law and it can help you figure out how to avoid damage to your perennial grass species. Cheatgrass has a few options for control that are outlined in the MontGuide “Cheatgrass: Identification, Biology and Integrate Management.” Some options include the use of herbicides such as glyphosate in early spring prior to seed production and prior to growth of desired perennial grasses. Imazapic and Journey can be applied late summer to early fall before of shortly after cheatgrass emergence and prior to planting desirable species. These are listed for range and pasture systems. Check out the MontGuide for more options. What does this ventenata look like? Dr. Jane Mangold’s August 2013 Weed Post describes it as typically 6-27 inches tall and color is tawny to light yellow. Key characteristics: reddish-black nodes in May-June; unusually long membranous ligule (1-8mm); open panicle in June-July; and lower awns that are straight and upper awns that are twisted and bent once the plant senesces in July-August.
My personal experience with ventenata starts with suspecting a patch of grass might looks similar to cheatgrass, but it doesn’t look quite right. Upon further investigation to nodes, ligules, and awns, my suspicions are confirmed. Now that I’ve convinced you (hopefully) that you don’t want ventenata to visit your pasture, what can you do to prevent its arrival? First, maintain healthy grasslands and limit disturbance while reduce the chance of any invasive plant from moving in. Second, reduce introduction by ensuring you don’t bring contaminated hay to your place.
For more resources read the MontGuide “Cheatgrass: Identification, Biology and Integrate Management” and Weed Post “Ventenata” from August 2013 or call Emily Lockard at the MSU Extension–Gallatin County office at (406) 388-3213. •
