Vine Disease on the Increase in Southwest France
A fatal fungal disease known as Esca is ravaging vineyards from Cognac to Bordeaux, with no cure in sight
Diana Macle
Posted: September 18, 2008
On Sept. 11, close to 500 disgruntled winegrowers took to the streets in Auch, France, one of the main towns in Gascony, to draw attention to a fungal disease. Esca, a vine disease that has long been a concern in France and elsewhere, is on the rise. The problem has grown since 2001, when sodium arsenite, the only product that keeps the sickness in check, was banned as a carcinogen. With no alternative treatment, the disease is on the increase, notably throughout southwest France, particularly Cognac and Armagnac, but also in Bordeaux.
Last year's official estimates indicated that up to 5 percent of the vineyard surface area in France was affected by Esca. This year the figure is expected to increase. "The disease has spread a great deal over the past 12 months, with up to 40 percent of some vineyards in Gascony completely destroyed," said Alain Lalanne, a winegrower actively involved in the demonstration. "We've asked for the right to temporarily use sodium arsenite, especially as the health risks are only a concern for those who apply the product to the vineyard."
Esca is especially prolific in southwest France because it thrives on the area's chief grape varieties—Cabernet Sauvignon, Sauvignon Blanc and Ugni Blanc. For unknown reasons, Merlot is much more resistant to the disease.
Alexandre Davy, a vine-growing research scientist in Bordeaux, explained that Esca destroys the woody parts of the vine plant, either over a number of years or in less than 12 months. "The slow form of Esca can be recognized by yellowish leaves and slow maturing grapes," he said. "The following year the vine may bounce back and appear perfectly normal, but the disease appears again, sooner or later, with fatal results."
The second form is much more brutal. "The vine doesn't produce any grapes at all and usually dies the same year," he said. The cause of the disease is not understood, though it may be triggered by one or multiple fungi attacking the vines.
According to the French government's plant protection agency, the mild and wet springtime weather conditions in southwest France during the past two vintages have favored the disease's development. In addition, the growers in this area are making the most noise as Cognac and Armagnac wines require high yielding vines. "Until a new remedy is found, growers should remove all infected vines, arms and cordons as soon as they are identified to stop the disease from spreading," said Jacques Grosman, a spokesman for the agency. "Another source of concern are nurseries, as they need to be able to guarantee that they aren't supplying infected planting material."
Dr. Philippe Larignon, who has been researching Esca for the past 25 years, said that a replacement for sodium arsenite will be found, but not in the immediate future. "Laboratories worldwide are looking for a solution, but only since 2001," he said. "It's true that sodium arsenite is a miracle product, but as it's much too toxic, there's no way that growers are going to be authorized to use it again."
