NEWS for North Dakotans
Agriculture Communication, North Dakota State University
7 Morrill Hall, Fargo, ND 58105-5665
April 20, 2000
The past winter was so mild in some areas of North Dakota that volunteer cereal grains which sprouted last fall have remained viable, and now these plants pose a disease threat to this year's wheat and barley crops. To avoid a "green bridge" that allows movement of wheat streak mosaic virus and barley yellow dwarf virus, producers need to destroy these potentially infected volunteers about two weeks prior to planting, says a North Dakota State University plant scientist.
"Producers should scout their fields and destroy any green-growing volunteers. By taking out these volunteers, we eliminate this reservoir of inoculum, and it is less likely to infect this year's crop," says Roger Ashley, area extension specialist at the NDSU Dickinson Research Extension Center.
Ashley says the problem of overwintering volunteers is not widespread, but on fields where the volunteers are present, producers should select between a tillage operation or a preplant herbicide (burn-down) application to destroy the plants. Herbicides containing glyphosate as the active ingredient, such as Touchdown or any of the Roundup formulations, are effective, as is Gramoxone Extra, whose active ingredient is paraquat.
After either a tillage operation or a herbicide application, producers should wait from 10 to 14 days before seeding. Ashley says, "By allowing this green bridge to remain in place, we're almost guaranteeing ourselves that we'll see these viral diseases this year."
In addition, volunteer cereals are good hosts for fungal root diseases, particularly root rot, Ashley says. If possible, producers should plant alternative crops such as peas, lentils, flax, sunflower or safflower on last year's small grain fields that had overwintering volunteers.
Producers who plan to re-crop their small grain fields to hard red spring wheat, durum or barley should consider using a seed treatment, but Ashley warns that seed treatments are not as effective as well-planned rotations for controlling root rots.
###
Source: Roger Ashley (701) 483-2349
Editor: Dean Hulse (701) 231-6136