WASHINGTON — Farmers used to worry about weeds. Then, herbicides solved that problem.
At least for a while.
In 1997, there were 432 new patents for herbicides; by 2009, there were only 65. Developing broad-spectrum glyphosate and “Roundup Ready” crops worked so well that people basically stopped looking for new herbicides.
But then the weeds started fighting back.
Reactions is a video series produced by the American Chemical Society and PBS Digital Studios.