Critics of genetically modified crops protested at Monsanto Co's annual shareholders meeting on Tuesday, calling for the world's largest seed company to provide a report on contamination in non-GMO crops and to stop fighting mandatory labels on foods containing GMO ingredients.

The requests came in the form of two shareholder resolutions that were backed by environmental, food safety and consumer activists groups. They claimed that more than 2.6 million members support their efforts.

The resolutions come at a time of heightened debate over the spread of genetically modified crops. Outside the meeting at Monsanto 's headquarters in suburban St. Louis, Missouri, about two dozen protesters waved signs criticizing the $15 billion agrichemical and seed company, and one man was arrested.

"We are asking for shareholders to vote in favor of transparency," said Margot McMillen, a Missouri farmer and member of the executive council of the National Family Farm Coalition who introduced one of the resolutions.

Both shareholder resolutions failed to pass after Monsanto officials recommended rejection of the proposals.

Company officials said the global debate over GMO crops prompted them to rethink how they communicate about their products.

Chairman Hugh Grant acknowledged that the company has not done a good job winning public trust, and told shareholders at the meeting that the company was changing its approach.

"There is a recognition that we need to do more," he said.

One of the resolutions put to shareholders sought a report on seed contamination of non-GMO crops, including costs of seed replacement, and crop and production losses, including losses associated with market rejections. That measure gathered 6.51 percent of the vote.

Critics say many organic and non-GMO farmers are dealing with contamination, and often chemical drift, from nearby GMO farms and should be compensated.

Monsanto executives said that the company already has stewardship practices that works to protect the co-existence of non-GMO crops with GMOs.

A related shareholder resolution called on the company to work with government regulators to set a standard threshold for foods containing GMO ingredients that should be labeled. That garnered 4.16 percent of the vote.

Grant said the company supports voluntary labeling efforts by individual food companies but added that mandatory labeling of GMO foods could confuse and mislead consumers if there is no meaningful difference in nutrition or safety of the foods.

More than 20 U.S. states are contemplating mandatory labeling of GMO foods, and Congress and the U.S. Food and Drug Administration are being pushed to act on this issue.

GMO critics say the spread of genetically modified crops is harmful to the environment, most notably by fostering herbicide-resistant weeds, and that the food made with the crops can be harmful to humans.

But the companies say that the crops are proven safe and that the proper use of the chemicals associated with the crops by farmers can mitigate environmental problems.

The most popular GMO crops are corn and soybeans that have had their DNA altered in ways that allow the plants to withstand sprayings of herbicide and to resist pests.