Mildew, a necrophilic parasite, is a fungus that develops in humid conditions. Once it appears, treatment does not comply with rules for organic agriculture. The only option consists in regular preventive spraying with copper sulfate, in the limit of 6 kg per year per hecture, over a period of 5 years. This method is thus delicate because it necessitates very painstaking surveillance of the whole vineyard.

« What saved us, said Philippe Cluzel, from the Domaine de la Tour in Languedoc (South of France) was following to the letter the recommendations of the Agricultural Chamber, that advised early treatment, each week, at very low levels , 300 to 400 g of pure copper per hectare. I did this every two weeks, but mildew quickly appeared anyway. So I had to maintain the schedule of spraying once a week until the summer.” For all concerned winegrowers, all around France, the only really effective treatment was warm and dry weather conditions.

Once the vineyard is affected, the only available treatments are the conventional ones. Organic winegrowers are thus confronted with a painful alternative: either surrender all or part of their crop or give up their organic status. If they use a conventional curative solution, they have to surrender their organically-grown status and start the conversion to organic agriculture from scratch, a three year process.

This is the most accepted version but it is sometimes contested by some growers, like Louis Delhon, from Domaine de Bassac in Languedoc. “It is unfair and dishonest to condemn organic viticulture when 2007 has been exceptional regarding mildew attacks, a threat against which there is no effective treatment, even within conventional phytosanitary solutions. My non-organic neighbors are suffering the same losses as I am. I am lucky that my vineyard is dispersed over a wide area, allowing me to compensate here what I lost there. For a plot where I lost 70 % of the crop, I found myself with a total grape deficit of 20 %, that’s not too bad. But it could have been worse if I had a vineyard with smaller surface, more compact, in a more exposed zone. The fact that I grow organic has nothing to do with these facts.”

Same remark with Pierre Guibal, of Domaine de Bannières, in Castries, near Montpellier, Languedoc.. « Once the mildew is there, what can we do? The damage is done. We are sticking with organic and we will draw conclusions for our own sake. In my case, I will make sure all areas of my vineyard are accessable, whatever the rain level or the quality of the soil may be, so I can apply all needed preventive treatments, when they are required.

The fact is that the Ecocert Certification Bureau, that delivers each year more that 8000 organic labels in France, with 80% being winegrowers, indicates that winegrowers surrendering their organic status were few, despite the exceptional virulence of the mildew this year. However, they will increase their vigilence against possible undeclared chemical treatments by 40%.