WASHINGTON -- Farm states like Missouri are eager to cash in on the potential of pharmaceutical crops, but a new report finds the benefits may be smaller than expected.

The report concludes that market forces will drive farmer compensation down and that the acreage needed to grow crops for bioengineering companies is so small, only a few farms will reap the benefits.

"Those looking at pharma crops as a boon to rural America view increased farm income as a key benefit," said the study's author, Iowa State University economics professor Robert Wisner. "In the end, economic principles dictate that only a small part of the pharma crops' value would be expected to go to growers."

Proponents of pharmaceutical crops questioned the report's credibility because it was funded by the Union of Concerned Scientists, a group that opposes biopharming.

"As far as their contention that this will not produce revenue for farmers, I don't know what they are talking about," said Dean Hubbard, president of Northwest Missouri State University.

Hubbard is trying to bring Ventria Bioscience, a California-based company specializing in plant-made pharmaceuticals, to anchor a new biologics center on campus, where genetically modified rice and other products would be processed.

"Our agreement with Ventria commits them to paying farmers substantially more, up to double what they are making per acre, for growing these crops," Hubbard said.

Ventria wants approval to grow rice in Missouri that has been genetically engineered to produce proteins found in human milk, saliva and tears. The proteins would be used in medicines to fight dehydration and other illnesses.

Ventria is already growing the rice in North Carolina, and other states have shown interest in reaping the financial rewards that could come from the emerging technology.

Wisner's report said the potential benefits to consumers and farmers don't address risks to the food supply. The costs of containing pharma crops to protect consumer crops may be high enough to outweigh potential savings in drug production, the report said.

Growers also could be at risk because they may lose domestic and foreign markets out of fears the rice is contaminated with drugs, the report said.

"Proponents of pharmaceutical crops have inflated the rewards and downplayed the risks," said Jane Rissler, a senior scientist with the Union of Concerned Scientists.

The report concedes that rural communities would benefit only if a drug processing company locates nearby.

That is just what Hubbard hopes will happen near his Maryville, Mo., campus. He said the university wants to help the biopharming industry develop in a way that is responsible and careful.

"Of course there are risks," Hubbard said. "There are also risks involved with doing nothing. But the potential benefits for human health to my mind are mind boggling."

Scott Deeter, Ventria's president, said the report ignores the potential benefits in advancing medicine.

"The benefits of plant-made pharmaceuticals are widespread, not just for farmers but for patients and the health care system in terms of affordable medicine," Deeter said.