Hawai'i won't ban genetically altered coffee, a decision that worries growers of the prized Kona coffee brand who want to keep it pure.

State lawmakers killed a bill yesterday that would have prohibited growing genetically modified coffee in Hawai'i until 2012. Instead, they want to order a study into the science, benefits and dangers of genetically enhanced crops.

Coffee farmers worried that genetically modified coffee could contaminate Kona blends, which are only grown on the Big Island and exported worldwide.

"The fact that you're creating a 'frankenfood' is very scary. What will it do to my morning cup of coffee?" asked John Langenstein, sales manager for Koa Coffee Plantation.

Coffee drinkers in Japan and parts of Europe wouldn't buy Kona coffee if it becomes mixed up with genetically changed coffee, causing it to lose its value and uniqueness, Langenstein said.

Others argue that genetically modified coffee poses little danger to Kona coffee because it would be grown on a different island, and it could benefit the economy.

One company plans to begin planting a special kind of modified coffee on O'ahu, likely early next year, that grows decaffeinated naturally.

"Our field trials would have absolutely no effect on Kona coffee, so it doesn't really make sense to ban field trials of transgenic coffee across the whole state," said John Stiles, chief executive officer for Integrated Coffee Technologies Inc.

Hawai'i lawmakers plan to form a task force to consider the merits of genetically modified coffee, labeling effectiveness and consumer education.

Lisa Gibson, president of the Hawaii Science and Technology Council, said legislators should avoid passing laws limiting scientific study.

"It's a very slippery slope to begin legislating research," Gibson said. "If we're going to diversify our state, it needs to be based on knowledge."