A New Threat to Pasture and Farm Land

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It looks like a dandelion. It has seeds like a dandelion. But this new and dangerous yellow weed creeping into your fields and pastures is no dandelion. Narrowleaf Hawksbeard is beginning to spread across the state, but one of the main areas of concern is Northeast Montana, especially in Valley County. Valley County Extension Agent Shelley Mills told us about this weed, what it looks like, where it comes from, and how to rid it from pasture and farm ground.

Narrowleaf Hawksbeard originated in Siberia, making Montana a prime place for it to thrive as weather conditions are very similar. Narrowleaf Hawksbeard made its way into Alaska and throughout Canada from both the west and the east, and Mills explains that there are two ways it may have travelled to Montana. First, it may have come in some seed, mixed with alfalfa, bought from Canada and used for conservation reserve acres. The second possibility is that it may have just blown across the border from Canada. The seed is very tiny making it hard to clean out of alfalfa and grass seed, and easily blown around. A single plant can produce 3,000 to 50,000 dandelion-like seeds and it can germinated in cold soil, as cool as 40 degrees, well before most other plants.

Narrowleaf Hawksbeard is easily confused with common dandelion, but dandelions bloom in the spring while Hawksbeard blooms in late June and July. Mills explains that Hawksbeard is a facultated winter annual meaning it germinates in the fall and forms a rosette that stays snow-covered through the winter. In the spring the rosette sends up to a 20-inch stem that blooms in a yellow flower.

Treatment of Narrowleaf Hawksbeard is a tricky situation. Once the plant bolts in spring it becomes very hard to kill. Mills explained, “One of my growers came in with a single plant that looked sickly but it was obvious it was still going to bloom and they said, ‘What is this weed and how come I can’t control it with my 64 ounces of Round-up in fallow?’”

Northeast Montana is particularly vulnerable to an invasive plant like this because farming practices have changed. Not many people fallow fields in that area anymore, and have switched to continuous crop and no-till operations. Hawksbeard is also beginning to appear in roadside ditches and overgrazed pasture land. Mills says the key is to get it sprayed in the tiny rosette period in the fall before the winter sets in. “It’s absolutely critical to do a late fall application. Then you come back in the early spring, as soon as you can get in the field, and spray again.”

Experts like Shelley Mills note that Narrowleaf Hawksbeard is probably all across Montana already, but just hasn’t been identified or recognized well enough yet. Producers are encouraged to learn to identify this invader, and take action to control it.

 

Source: Northern Ag Network & 

Valley County Extension Agent Shelley Mills


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