KANSAS CITY, Mo., Feb 25: More than 90 Texas cotton farmers have sued Monsanto Co. and two affiliated companies, claiming they suffered widespread crop losses because Monsanto failed to warn them of a defect in its genetically altered cotton product.

The lawsuit, which was filed in federal court in Marshall, Texas, seeks an injunction against what it calls a longstanding campaign of deception, and asks the court to award both actual and punitive damages.

In addition to Monsanto, the suit names Delta & Pine Land Co. and Bayer CropScience L.P., producers and retailers of Monsanto’s biotech cotton. A Delta & Pine Land spokeswoman said the company had no comment and no one for Bayer, a unit of Bayer AG , returned phone calls seeking comment.

Monsanto, which denies the allegations, wants the complaints removed from the court system and handled through arbitration. About half of the farmers agreed this week to enter into arbitration, but others have not. A hearing on the matter is scheduled for Monday in Austin.

The farmers’ essential claim is that Monsanto’s “Roundup Ready” cotton did not tolerate applications of Monsanto’s Roundup weed killer as it has been genetically altered to do.

The farmers claim there is evidence that the promoter gene inserted into the cotton seeds in the genetic modification process does not work as designed in extreme high heat and drought conditions, allowing herbicide to eat into plant tissue, leading to boll deformity, shedding and reduced yields.

The plaintiffs claim Monsanto knew this but did not disclose it so the farmers would continue to buy and use Monsanto’s Roundup herbicide.

We feel like Monsanto’s been lying to us all along, said B.B. Krenek, a Wharton, Texas cotton consultant who is working with a number of affected farmers.

Monsanto spokesman Andrew Berchet said there is no evidence that anything other than the weather is to blame for the technology that caused the crop losses.

As far as we can tell this is weather related. The month of June was one of the driest and hottest in more than a century, said Berchet. We don’t see evidence that this is related to our product.

Alan Stasney said he has evidence in his fields. A strip of cotton four rows across and 3,000 feet long that inadvertently was not treated with roundup yielded 1,051 pounds of lint per acre at harvest, while on either side of those rows—Reuters