When weeds begin showing resistance, it’s not a case of the herbicide changing the weed, it’s a simple “survival of the fittest” case, according to a Texas A&M AgriLife Extension Service specialist. Scott Nolte, Ph.D., AgriLife Extension weed specialist, College Station, said the common misconception is the herbicides cause changes. Instead, it’s mainly the inherited ability of a species to survive. “The problem is these resistant plants become parents because they were not killed out,” Nolte said. “It’s more of a selection, because they were left.” Building resistant weeds Target-site mutation is the most common cause of herbicide resistance, he said. This is where ...