By Dan Charles, NPR
Washington, DC – In the age-old struggle between farmers and weeds, farmers have enjoyed the weed killer Roundup. Some have called it the herbicide of a lifetime.
But after 30 years on the market the chemical seems to be losing its power over some weeds, changing farming practices nationwide.
It also means more work for St. Louis-based Monsanto.
NPR's Dan Charles prepared this report for Morning Edition. To hear it, click here.