Common waterhemp, Palmer amaranth, giant and common ragweed, Italian ryegrass and marestail are all part of a growing group of yield-reducing weeds to watch out for in the United States. With confirmed resistance to multiple herbicides, these species are top of mind for farmers this season.

“To keep ‘watch-out’ weeds in check, farmers should plan to use a herbicide program that effectively targets the weeds using herbicides with different sites of action,” said Luke Bozeman, Technical Market Manager, BASF. “Incorporating a diverse herbicide program – along with identifying local weed pressures and reviewing previous weed escapes on a field specific basis – will help farmers build an effective weed management plan specific to their farm.”

According to the Weed Science Society of America, weeds cause more yield loss and add more to farmers’ production costs than insects, diseases, rodents, birds, and grazers, such as deer. Experts recommend farmers carefully manage any weeds – resistant or not – with herbicides that offer multiple sites of action, ensuring they don’t turn into the next crop of “watch-out” weeds.

“I’ve always been a little concerned about using the same chemical on the same ground year after year after year,” said Missouri grower Gary Porter. “I try to switch it up if I can.”

For Minnesota grower Rob Hiniker, it’s all about staying one step ahead of weeds.

“A few years ago, we started using products like Optill PRO herbicide and Verdict herbicide to achieve early weed control and use multiple sites of action,” said Hiniker. “An aggressive program like this helps me gain efficiency in applications, limits weed competition and minimizes the opportunity for weather to impact my ability to apply a post herbicide.”

To stay clean, farmers should use proven herbicides that offer residual control through early-to-mid season and control any weed escapes as soon as possible.

“Proper weed management requires focus throughout the season,” said Bozeman. “Treat every weed like a tough weed and get it out of your field as soon as possible. Or better yet, never let it in.”

BASF notes it is dedicated to providing solutions, technical support and educational tools to help growers implement a weed resistance management program based on herbicide best practices. The BASF portfolio of solutions consists of herbicides targeting 12 different sites of action for effective control of resistant weeds. An extensive line of herbicides provides a multi-year rotational plan that allows growers to apply herbicides throughout the growing season to deliver management flexibility.

BASF has a herbicide rotation plan website: