Monsanto Corp. faces a treble damages class action alleging that its pesticide Dicamba poses such a risk to farmers they are forced to purchase resistant seed — marketed under patent at high prices by Monsanto — to avoid catastrophic damage to their crops from pesticide drift.

A North Dakota farm alleges it bought and Monsanto’s dicamba-resistant soybean seeds to avoid damage from nearby farms using the pesticide. The complaint, filed Feb. 1 in Missouri federal court, says that Monsanto recklessly marketed a pesiticide shown to be very volatile and very mobile from target fields to neighboring areas. As a result, it alleges, farmers with no intention to use Monsanto’s dicamba pesticide still must purchase its marketed resistant cotton and soybean seeds or risk heavy crop damage.

“Monsanto’s monopolization and attempted monopolization of the seeds market stymies competition, hurts producers, and harms the public at large,” the plaintiff Forest River Farms alleges. It alleges a class of “all individuals and entities who directly purchased seeds containing Monsanto’s dicamba-resistant trait.”