27 Sep Understanding the Vineyard
One of the fascinating things about wine is the people it attracts and the range of emotions it engenders.
For some people, it has to be organic, or even biodynamic, and we can understand where they’re coming from. Wine can be a beautiful product of the land, a sensuous experience that connects us to a time and place where the sun shone, the vines pushed their roots amongst ancient rocks and soil, and expressed it as a glowing liquid, aromatic, delicious and affecting. Naturally we want to know that this arises from care for the land and care for our health, and what could be simpler than to insist that it should be done without man-made chemicals?
The only hitch is that sometimes reality gets in the way. While all good viticulturists use a range of management techniques to reduce the threat of pest and disease, spraying is one of the tools that needs to be used. Organic growers still spray their vines, because after all, a vineyard is a thundering great food resource for something like the powdery mildew fungus. But instead of spraying a man-made chemical to control powdery mildew, they spray a ‘natural’ chemical, elemental sulphur. It’s this distinction between synthetic chemicals and ‘natural’ chemicals that’s the problem. After all, uranium, mercury and lead are all natural elements, but you wouldn’t want to use them where you grow food.
Elemental sulphur is a very good fungicide, with a complex mode of action against powdery mildew, making it hard for the fungus to develop resistance. Unfortunately it’s also a miticide, killing not only harmful mites in the vineyard such as rust mite and bud mite, but also the beneficial mites that normally control the harmful mites. Over a number of seasons at Mount Majura Vineyard, we observed damage to the vine leaves after hot weather, typical of sunburn caused by earlier damage to the leaf surface by rust mites feeding. Last year for the first time, we completely eliminated sulphur from our spray program, replacing it with synthetics that are designed to target just the powdery mildew fungus and tested for minimal activity against beneficials. The result was very encouraging: no rust mite damage, despite very hot summer weather that would usually trigger it.
So we’ll continue using whatever techniques we evaluate to be the most safe and harmless to our vineyard environment, regardless of ideology and simplistic rules. We’re here to nurture the land, and through that make those wines that express its beauty. What works well for one vineyard may be different to what suits another, so remember that the next time someone insists that wine should be organically grown, it might not be that simple, and it’s worth knowing more about who made it and how.