Data collection activities in June 2019 at Boulder Lake in the Bridger-Teton National Forest near Pinedale, Wyoming, USA. Author: Roman Boris

Downy mildew is an invasive annual grass that has been known to ignite devastating wildfires in the vast grasslands of western North America. Scientists say the weed poses a significant threat to native sagebrush ecosystems, as well as to the people and wildlife that depend on them.

Imazopic herbicide is often used to control weeds. Unfortunately, re-invasion from the downy seed bank is common after imazapic treatment.

In an open access article published in Volume 15, Issue 3 of the journal Invasive Plant Science and Managementresearchers describe a five-year field study comparing the effectiveness of imazapic with that of indosiflam – more new herbicide recently labeled for use in pastures where livestock graze. Researchers compared the ability of two herbicides to reduce downy brome and promote the regeneration of native perennials the grass the cover

While imazapic initially reduced downy brome, the control disappeared after 21 months. Indoflam, however, produced longer-term benefits.

“In some circumstances, a single application of indosiflam controlled blisters throughout the five-year period of our study,” says Jacob Kurkamp, ​​a doctoral student at Colorado State University. “This suggests that indosiflam can help achieve that a weed management targets that cannot be achieved with other herbicides, and that indosiflam can be a powerful weed control tool working to mitigate the effects of invasive annual grasses in pastures.”

Studies show that combining herbicides with prescribed burning improves downy mildew control

Additional information:
Jacob S. Courkamp et al., Indaziflam reduces downy brome (Bromus tectorum) density and cover five years after treatment in sagebrush meadows without affecting perennial grass cover, Invasive Plant Science and Management (2022). DOI: 10.1017/inp.2022.21

Citation: Research Shows Path to Long-Term Control of Downy Brome (2022, October 12) Retrieved October 12, 2022, from

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