Herbicide resistance can be a daunting factor when considering weed control strategies for no-till fields. Controlling weeds early with a variety of methods can help, according to Bryan Young, professor of weed science at Purdue University

Species that have become difficult to manage because of herbicide resistance include Palmer amaranth, waterhemp and horseweed, aka marestail. Young says some species have adapted to the corn and soybean production system. 

“We tried to trick it by going from one crop that’s an annual, such as corn, to soybeans, and we think that’s going to fool the weeds enough that we’re going to control them better,” he says. “Well, we might need to be a little bit more creative in some respects.”

Young says that while herbicide discovery slowed down after the success of Roundup Ready, research has “ramped back up.” Still, he doesn’t expect any major new herbicides during this decade. Current herbicides are used for new crop traits as well, so Young wonders how long those herbicides will last.

He adds that regulatory constraints, such as those in the Endangered Species Act, will impact herbicide use as well. For example, atrazine rate application could be cut by 50%. These challenges add to the need for multiple weed control methods.

“It’s going to get more difficult,” Young says. “Weeds are going to continue to evolve and be more problematic, and we’re losing some of the herbicide tools that were important to us…