The National Corn Growers Association joined five other commodity groups in sending a letter to Commerce Secretary Gina Raimondo on possible herbicide tariffs. The groups are asking the secretary to consider the impacts on farmers as she reviews a petition by ag chemical company Corteva that would place duties on imports of the herbicide 2,4-D.

“Restricting imports of 2,4-D will have wide-ranging consequences for farmers,” the letter said. “American farmers cannot solely rely on Corteva, which is the only domestic supplier of 2,4-D, because there’s not enough to meet demand.”

The letter also says that if granted, the petition would cause availability shortages and hamper growers’ ability to be successful. “Restricting the availability of 2,4-D will be very harmful at a time when farmers are grappling with rising input costs and low commodity prices. Farmers can’t handle additional costs in what’s already a period of tight margins.”