Syngenta agronomists are calling last year’s most noxious weed, Palmer Amaranth, the number one weed to watch for in 2017. It’s continuing to spread north into new states and shows resistance to multiple herbicide modes of action.
Palmer Amaranth has earned the title of top weed as it’s reduced soybean yields up to 79 percent and corn yields 91 percent. Palmer Amaranth was found in Minnesota for the first time last fall, coming a year after the first sighting in South Dakota. States are now confirming the spread of Palmer Amaranth that is resistant to multiple herbicides. Last October, the University of Missouri identified an infestation that was resistant to glyphosate and PPO inhibitors. The more producers apply a particular mode of action, the quicker Palmer Amaranth not only becomes resistant but spreads those resistant genes to other locations. Things producers can do to help slow the spread include regular mowing of ditches, waterways, and field borders. They should also meticulously clean machinery like combines. To delay or prevent growth in fields, producers need a program that integrates a portfolio of herbicides together with complementary practices like crop rotation.
From the National Association of Farm Broadcasting news service.
Image courtesy of UC Agriculture and Natural Resources