|
|
Watch now for winter annual weeds in wheatKansas Winter annual weeds are faring well this fall in winter wheat fields, thanks in part due to ample precipitation throughout much of Kansas. Dallas Peterson, Extension weed specialist at Kansas State University, says that in fields where growers have experienced past problems, grass and broadleaf weeds can be a challenge this fall. "If you had problems in that field in previous years, especially in continuous wheat, rest assured you're going to have a problem this year," he explains. Taking frequent good, hard looks at wheat fields from now until dormancy is a good idea, particularly when it comes to grassy weeds. "I always encourage farmers to scout fields for weeds, but you have to look close to see them in the fall. You're not going to see them from the road. When winter annual grasses have just one or two leaves, they're easiest to kill," says Peterson, who adds that many farmers might be surprised at how invasive these weeds can be in the fall. "In most cases, when people think they don't have a problem in the fall, but then they go back in the spring and see a lot of weeds they were probably already there in the fall." And fall, he points out, is the best time to treat these problem grass and broadleaf weeds. "If you have grasses such as cheatgrass, rye or jointed goatgrass and you're pretty confident you are going to treat the field some time during the season, fall is clearly the best time to make a herbicide application," he says. Wheat producers have a broad spectrum of weed control products to choose from. Although they come from four different companies, Powerflex, Olympus, Olympus Flex, Beyond and Maverick all are similar in how they work. "All of these herbicides are very good for control of cheat and Japanese brome, but they're not quite as good on downy brome and they work better as a fall treatment than in the spring," he explains. "All have the same mode of action and that's important, since we are starting to see some resistance in our cheat populations to the ALS-inhibiting class of herbicides. When we have resistance to one of those herbicides, we generally have resistance to all of them because they all work the same way." Many producers are rotating wheat into a summer-planted row crop, Peterson says, in which case paying close attention to the rotation restriction on the herbicide's label is critical. "Another advantage of a fall application is the longer interval before planting a summer row crop, which may allow you to plant certain row crops the next summer, whereas a late spring application may not fit into those guidelines," he adds. Peterson adds that this fall's ample precipitation has been beneficial for winter annual broadleaf weeds like mustard, field pennycress and henbit, all of which go dormant over the winter but resume growth in the spring. Many of the herbicides mentioned above will suppress the winter annual broadleaves too. A new product--Huskie, from Bayer Crop Science--features excellent control of winter annual broadleaves, although it has no effect on winter annual grasses. Huskie has a bleaching mode of action and is a viable alternative to existing broadleaf herbicides, especially in areas where ALS-resistant broadleaf weeds are present. For more information on weed control in wheat, Peterson recommends studying the K-State Publication called, 2009 Chemical Weed Control, available at local Extension offices or online at www.ksre.ksu.edu/library.
Copyright/Privacy
Copyright 1995-2011. High Plains Publishers, Inc. All rights reserved. Any republishing of these pages, including electronic reproduction of the editorial archives or classified advertising, is strictly prohibited. If you have questions or comments you can reach us at High Plains Journal 1500 E. Wyatt Earp Blvd., P.O. Box 760, Dodge City, KS 67801 or call 1-800-452-7171. Email: webmaster@hpj.com |
|
