Few people are aware that the origins, or at any rate the roots, of the French wine industry came from the United States towards the end of the nineteenth century. French vineyards had been almost destroyed by a sap-sucking insect, the grape phylloxera, which was carried accidentally by ship from North America and spread remorselessly. As soon as it became apparent that only the embryonic American vines were resistant to the voracious insect, French vineyards were given a dramatic and secret makeover. American plants had European grapevines grafted on them, and the same US strain has been used surreptitiously ever since.

The same kind of drastic measure, but one based on genetic modification not the import of foreign plants, is now advocated to beat the latest pest. Almost one third of French vineyards are infected by the fan-leaf virus, which turns leaves yellow and kills the flowers before they can form fruit. This reduces both the volume and the quality of the annual wine harvest.

Scientists have created a genetically modified rootstock which they believe will send a virus-killing RNA, the nucleic acid present in all cells into the grapevine, making the entire plant immune.

However, it will be two years before the results of this controversial experiment, protected by high barbed-wire fences and watchtowers with searchlights, are known and resistance to the concept of genetically modified plants is growing. Moët et Chandon, perhaps the most famous of the champagne producers, tried a similar experiment of their own in the early 1990s, only to abandon it hastily in 1996 when the story broke in the French press.

Olivier Lemaire, leading scientist on the project