A US court has dismissed a case brought by organic farmers against GM seed giant Monsanto.

The Organic Seed Growers and Trade Organisation (OSGATA) and a consortium of other growers and organisations had challenged Monsanto’s patents on its genetically modified seeds.

The group had been seeking court protection against possible lawsuits by Monsanto for patent infringement if genetically modified crops were mistakenly found among their yields, for example, through cross-pollination.

But a judge threw out the case, saying that Monsanto had not taken any action – or even suggested suing any of the plaintiffs.

US district judge Naomi Buchwald, for the southern district of New York, criticised the groups for a “transparent effort to create controversy where none exists”.

In its ruling, the court cited Monsanto’s long-standing public commitment that “it has never been, nor will it be, Monsanto policy to exercise its patent rights where trace amounts of our patented seeds or traits are present in a farmer’s fields as a result of inadvertent means”.

Daniel Ravicher, a lawyer for the plaintiffs, said the decision was “gravely disappointing”, adding that the plaintiffs would appeal.

But David F Snively, Monsanto’s executive vice-president, secretary and general counsel, said: “This decision is a win for all farmers as it underscores that agricultural practices such as ag biotechnology, organic and conventional systems do and will continue to effectively coexist in the agricultural marketplace.

“Importantly, this ruling tore down a historic myth which is commonly perpetuated against our business by these plaintiffs and other parties through the internet, noting that not only were such claims unsubstantiated but, more importantly, they were unjustified.”

Monsanto believes that all farmers should have the opportunity to select the production method of their choice, whether it’s organic, conventional or the improved seeds developed using biotechnology.

Monsanto is the world’s largest seed company and a leader in development and marketing of genetically altered soya beans, maize and other crops.

The company has staunchly defended its patents on its genetically altered crops, which include patented Roundup Ready soya beans, maize and cotton.

The crops are popular with US farmers because of their ability to withstand herbicide treatments.

Many US farmers have claimed that their fields were inadvertently contaminated with Monsanto’s biotech seeds without their knowledge, and the issue has been a topic of concern not only for farmers, but also companies that clean and handle seed.