HILO >> A second Hawaii county has approved a bill addressing genetically modified crops.

The Hawaii County Council voted 6-3 on Tuesday to approve a bill restricting the planting of genetically modified crops to enclosed structures like greenhouses, the Hawaii Tribune-Herald reported.

Mayor Billy Kenoi must choose whether to sign the legislation, veto it or let it take effect without his signature.

Farmers who already grow genetically modified crops would be exempted from the new ban. That includes papaya growers, who largely rely on transgenic varieties that are resistant to the ringspot virus, and the Big Island Dairy.

Previously, the county adopted a more limited genetically modified organism bill that banned transgenic coffee and taro. That was passed in 2008.

The new bill curbs the further adoption of GMO crops. It also likely would restrict research of new modified varieties since open-air testing will be banned, University of Hawaii scientists have said.

Kohala Councilwoman Margaret Wille, who introduced the measure, said she is trying to be protective of the environment and non-GMO farmers.

“I think it’s a very important step, a very modest bill,” she said.

A dozen Big Island agriculture organizations opposed the measure, said Lorie Farrell of Hawaii Farmers and Ranchers United.

Opponents said it will give growers elsewhere a competitive advantage. They also say discussion among council members was not significant before the meeting.

Two other farming groups — Hawaii Farmers Union United, whose focus is on family farms, and the Kona Coffee Farmers Association — supported it.

Farmers supporting the legislation expressed concern about cross-pollination between modified and non-modified crops, which they say can hurt or even close their markets.

Voting no were Hilo Councilman Dennis Onishi, Council Chair J Yoshimoto and Puna Councilman Greggor Ilagan. Puna Councilman Zendo Kern voted yes with reservations.

The Kauai County Council voted Saturday to override a veto of a bill requiring large farms to disclose use of genetically modified crops.