New weeds can be managed by new herbicides — but those herbicides have first to make it through the technology-resistant political/regulatory process.
“Last year’s drought took a big bite out of the two most prodigious US crops, corn and soy. But it apparently didn’t slow down the spread of weeds that have developed resistance to Monsanto’s herbicide Roundup (glyphosate), used on crops engineered by Monsanto to resist it.”