A contentious and complicated issue. It would be good if we could get rid of the blind dogma, emotion and throw more light on the subject. Last year, I had a brief exchange with Stephen Skelton MW, a leading expert in the field. I reproduce below (with his permission) the original, and unedited, letter he sent to Decanter Magazine in 2013.
More recently, I was very pleased to read an article that talks a lot of sense from a leading group of wine journalists Les 5 du Vin: Le “bio” lave-t-il vraiment plus blanc que blanc ?
PESTICIDE USE (Letter to Decanter Magazine)
“Your article headed “Pesticides found in 90% of French wines tested” was both sensational for the sake of it and inaccurate. It could just as well have been headed: “Known killer drug found in 99% of all wines” and then continued: “Alcohol, a highly addictive drug known to be responsible for early deaths plus problems such as crime, driving accidents, violence and marital break-up, has been found in all wines, sometimes accounting for as much as 16% of the total. What is more, producers, far from lowering alcohol levels in their wines, have seemingly been raising them in the last few decades.”
The truth is that the appearance of pesticide residues in wine has more to do with better testing techniques than it has to do with the amount of chemicals which producers spray on their vines. Not only are vines naturally healthier than ever, producers have better monitoring and prediction methods and better sprayers, all of which mean that the amount of chemicals used is less today than it was 20 years ago. In addition, there are today regulations covering almost every aspect of pesticide use including buffer zones, longer harvest intervals, re-entry periods, making their use safer for the public the environment and the operator.
As for organic and biodynamic growers, it is interesting to note that residues were found in their wines too, probably not because of contamination by their neighbours as was suggested, but probably due to the copper they spray on their vines in lieu of modern synthetic anti-mildew chemicals which break down in both the plant and the soil – something copper does not.
As for cutting the use of pesticides, this is a very difficult thing to measure. If you phase out a pesticide that has an application rate of 6 kg/ha for one that has a rate of 1 kg/ha this might look like a reduction, but the product with the lower rate might be far more powerful than the one with the higher rate. If you decide to use more natural products and less synthetic ones, on the face of it a ‘good’ thing, your use rates will rise hugely as these are required in much higher quantities to be effective.
All responsible growers do their best to minimise their use of chemicals in vineyards as it is both in their interest to save money and in the interest of the public and the environment. Maybe one day there will be GM vines which have been produced to be naturally resistant to mildews, botrytis and other ailments, but until then, in most situations, vines will need some form of chemical intervention to keep them and their grapes healthy.
Stephen Skelton MW”