French winemakers grapple with 'incurable' grape disease

French winemakers have demanded emergency funding to deal with an "incurable" grape disease that they fear could become as devastating as a 19th century plague that almost destroyed the nation's vineyards.

The fungal disease esca has infected 13 per cent of France's vines this year, costing the industry more than €1 billion ($AUD1.4 biillion). It is transmitted by airborne fungi and the only known treatment, sodium arsenite, is banned because it is carcinogenic. Once the disease is detected, vines have to be ripped up and burnt. It stunts their growth and can cause them to wither and die rapidly.

Vineyard owners, many of whom were already struggling to make ends meet, are facing catastrophic extra costs because their yields have fallen drastically and they have been forced to plant new vines.

The resurgence of the disease, which dates from Roman times, was detected in mid-August on sauvignon vines in the Loire Valley. It has now spread elsewhere in France and has been found in other European winemaking countries and California.

French wine industry leaders are urging the European Union and national governments to declare the fight against esca an international emergency and provide funding to step up research to find a cure or a preventive treatment.

"We're worried that it could spread like wildfire," said Guy Vasseur, the head of the Permanent Assembly of France's Chambers of Agriculture.

Mr Vasseur called for action before the fungus "becomes like phylloxera" - a tiny pest that ravaged vineyards across Europe and all but wiped out the French wine industry in what was known as the Great Wine Blight in the late 19th century.

"We've tried a lot of things but nothing has worked so far," he said. "We haven't got a solution and all we can do is remove vines and plant new ones."

Some winemakers are so desperate that they have started playing music to their vines in the hope that it will make them resistant to the fungi that spread esca. Scientists have suggested that "protein melodies", or "proteodies", may encourage growth and inhibit fungi. The idea is that as protein molecules form, they create a sound, and if that sound is replicated, plants will respond.

However, the practice has drawn comparisons with the folk remedies tried against phylloxera without success. After pesticides and chemicals proved ineffective, growers resorted to burying toads under their vines to draw out the "poison". Some let their poultry roam free in the hope that they would eat the insects.

The epidemic was only curbed by grafting on aphid-resistant American vines in a process known as "reconstitution" that had to be painstakingly applied to the majority of France's vineyards.

Mr Vasseur acknowledged that the EU was already funding some research and local authorities in France had been helping winegrowers finance replanting, but he said more needed to be done.

The French wine and spirits industry is worth more than €13 billion a year.

Lifting the ban on sodium arsenite has been ruled out on health grounds.

The Telegraph, London