Colmar, France: French scientist Jean Masson carefully unlocks the gate of a heavily protected open-air enclosure. Behind the fence and security cameras there are no wild animals or convicts, just 70 vines.
In the heart of the picturesque Alsace wine region, researchers have planted France's only genetically modified vines in the hope of finding a way to battle the damaging "court-noue" virus afflicting a third of the country's vines.
The modified plants will not grow grapes or yield any wine, and scientists at the state-financed National Institute for Agricultural Research (INRA), which is conducting the experiment, say it is safe.
"The environmental risk is nil," said Masson, head of INRA in the eastern town of Colmar. "We have taken all safety measures."
But many local winegrowers fear the plants will contaminate their vineyards and ruin the reputation of France's wine industry.
"It makes me angry because this is imposed on everyone without us being informed about the risk," Pierre-Paul Humbrecht, a maker of bio wines, said in his vineyard just a few kilometres away from the open-air experiment.
"If there's a problem, it concerns us all. We fear for our vines."
In France, resistance against genetically modified food is fierce.
INRA stopped its first tests on genetically modified vines in the Champagne region in 1999 following protests. After years of talks with locals and winemakers, Masson said his researchers had now set up enough safety measures to satisfy critics.
They dug a hole of the size of a basketball court, put in a cover to shield the natural ground and planted the contested vines on soil from outside
The plants are also surrounded by some 1 500 normal vines.
The prison-style fence was a request by environmentalists, who wanted to prevent animals and human intruders from carrying parts of the plants outside the enclosure, Masson said.
Masson said INRA conducted tests only in the lower part of the vine, the rootstock, which did not carry any grapes.
Almost all French winegrowers have used separate rootstocks since the phylloxera pest nearly wiped out the European wine industry in the late 1800s.
In response to the tiny louse, which attacks the root system of vines and was accidentally brought to Europe from America in 1860, European winemakers imported resistant American rootstocks and grafted their vines onto them.
INRA says no genetic information can pass from this rootstock into the plant's upper part - which grows the grapes. But to ease fears that a modified plant could one day yield wine, the researchers will strip the vine of any blossoms.
"We don't want to produce grapes. We want to answer the scientific question of whether this transgenic (genetically modified) root can lead to the plant developing durable resistance to this virus," said INRA's Olivier Lemaire, who is in charge of the project.
Winemakers agree the court-noue virus is causing havoc but they disagree over whether INRA's research is needed.
Masson said the scientists did not want to market their test results, pointing out that scientific publication would be the ultimate goal when the experiment ends in four years' time.