BRANDON – Manitoba farmers are lucky: only a handful have problems with downy brome and Japanese brome.
But that’s no excuse to remain happily ignorant of the weeds, which are ravaging fields across the U.S. Great Plains and on the Canadian Prairies.
“If you don’t know downy brome and you don’t know Japanese brome, get to know them,” Bruce Murray of Manitoba Agriculture urged farmers during Manitoba Ag Days in Brandon.
“These, to my mind, are wild oats on steroids. You need to be very afraid of them.”
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Downy brome and Japanese brome are grass weeds that look like wild oats or foxtail barley at some stages if they’re not examined closely. They are hairy and the seeds have long spikes that cattle will not voluntarily eat.
Murray said the weeds are beginning to appear at a few places in Manitoba. Right now Manitoba Agriculture is aware of 30 infested fields, but believes there are more that farmers have not identified yet.
It isn’t just a small, patchy problem when it appears, Murray said.
“Most of the fields we’re dealing with are corner to corner,” he said.
“These guys are not poor farmers. Something’s going on.”
The two brome weeds will devastate a cereal crop if not eliminated. They can germinate in the fall and erupt in the spring.
They are a particular problem in winter wheat and fall rye, crops in which they can hide and on which certain grass-killing herbicides can’t be used.
Once the plants are beyond the seedling stage they are difficult to kill and can easily overcome a cereal crop.
Murray thinks many of the infestations blanket an entire field because the weed seeds are coming in either in seed or on combines.
Custom combining is probably spreading the weed seeds, picking them up in infected North Dakota, southwestern Saskatchewan and southern Alberta and dumping them in Manitoba.
Poorly cleaned winter wheat and fall rye seed will be the equivalent of seeding a weed crop.
Murray said downy brome and Japanese brome thrive in zero-till systems. One way to set them back is to till the soil and wreck them early, in fall or spring.
Another way is to strip away their favourite cover: fall-seeded cereal crops.
“If you’ve got it, get the heck out of winter annual crops. Get into (spring) species. Throw a curveball at it,” Murray said.
A number of Group 1, 2 and 3 herbicides can control the brome weeds. A handy combination is trifluralin and tillage, which applies the herbicide correctly and damages the weeds.
The most important step is knowledge. Farmers need to be able to identify the weeds so that they can kill them quickly if they appear.
“The best thing you could do for your farm is to ID them. If it shows up in a small patch, get rid of it.”
