Weeds have evolved to be resistant to herbicide after herbicide, starting with synthetic auxins, then triazines, then ACCase inhibitors, then ALS inhibitors and now glyphosate, the main ingredient in Monsanto’s Roundup, according to Director of the International Survey of Herbicide-Resistant Weeds Ian Heap, who helps run Weedscience.com, the central repository for scientifically backed, peer-reviewed herbicide-resistance cases....Honestly, that is all common sense. What surprises me is that the most herbicide-resistant cases by an individual crop are for wheat. Around here there isn't a whole lot of wheat grown, and what is grown doesn't get sprayed near as much as the corn and beans (I'm assuming because the growth pattern of wheat confounds our winter and spring weeds). If you asked me, I'd guess corn, then soybeans then wheat. I'd be wrong, apparently.
According to Mr. Heap, “Unfortunately we have not seen any new herbicide sites of action in over 30 years, and it is not clear that any new ones are in the pipeline.” This means that the focus is shifting to preventing resistance to herbicides in the first place. According to Steven B. Mirsky a research ecologist at the USDA’s Agricultural Research Service, there are a number of ways to reduce herbicide resistance using weed-management tools such as cover crops. Heap also suggests rotating crops and herbicides to avoid resistance. Science Policy Director of National and Regional Weed Science Societies Lee Van Wychen suggested one of his favorite quotes: “If you had great weed control this year, do something different next year!”
Monday, June 23, 2014
More On Herbicide-Resistant Weeds
The WSJ has this chart: