Shift in weed spectrum triggers change
Many spring wheat growers on the Northern Plains are reporting several hard-to-control weed species are getting a foothold in areas where they had not been a problem in the past.
There has been more Persian darnel in the southwest corner of North Dakota, although experts say it's not an epidemic. Researchers also are seeing more downy and Japanese bromes, as well as more yellow foxtail pressure. Wild oats remain a major problem in North Dakota, but in many areas the spectrum is shifting more toward Persian darnel and Japanese and downy bromes. Historically the bromus species were more of a problem in far western North Dakota, but they are now seen as far east as 60 miles west of the Red River Valley.
A number of factors, including changes in tillage practices, may be contributing to the shift. Many growers are finding that their existing herbicide programs are not effective against these newer species.
Proper weed identification is the foundation of successful control. Growers should contact a county agent if they see an unusual weed in their fields. Once growers know exactly what is in their fields, they can adjust their herbicide programs to control it.
Larry Pavlicek, who farms near Dickinson, N.D., added Rimfire herbicide from Bayer CropScience to his tankmix when bromus and Persian darnel showed up in his fields. Rimfire offers strong activity on more than 30 tough grasses and broadleaf weeds.
"The results were exceptional," Pavlicek said. "It controlled my weeds all of the way through, even in a drought year."
He applied the herbicide in a tankmix with Huskie herbicide from Bayer CropScience when weeds were between 2 and 3 inches tall. Pavlicek treats every acre of wheat at the recommended application rate.
A similar program could help other growers who are trying to get a handle on bromus and Persian darnel. Changing the herbicides used in an existing program or adding Rimfire to the mix may be necessary for solid weed control this season.
Rimfire is a good fit because of its broad spectrum. It controls existing weeds such as wild oats and green and yellow foxtails, as well as the newer ones such as Persian darnel and Japanese brome. An added benefit to Rimfire is its rotational flexibility with key crops, including sugarbeets after wheat.
For more information, call a local Bayer CropScience Cereal Expert representative or 866-99-BAYER (866-992-2937), or visit www.cerealexperts.com.