Oh my!!! Treating vines with sulfur or cow's milk against powdery mildew ??
Would cow's milk be an alternative to sulfur in Champagne against powdery mildew?
It's important to say that you need a certain volume of slurry made from cow's milk per hectare to effectively reveal the benefits of this beverage against powdery mildew!!!! But is it 100% revolutionary?
Long used by some BIODYNAMISTSfor a long time, cow's milk is of interest to a growing number of farmers, particularly in ORGANIC. Their aim is to limit the amount of sulfur used, or even to do without it, still in the fight against powdery mildew. This craze has been reinforced by the European authorization of this product as a base substance in July 2020. But what does science have to say?
In 2006, Australian researcher Peter Crisp published his first major study, in which he concluded that milk was potentially as effective as sulfur. This was an opportunity to highlight two proteins with antifungal action: lactoperoxidase and lactoferrin.
In France, in 2009, Nicolas Constant of the Sudvinbio association drew on this work to conduct his own trials on 2 grape varieties (Carignan and Chardonnay). His conclusions were more mixed. The " raw milk " modality showed better results than the untreated control, but still inferior to those obtained with whey or sulfur.
"At this level of effectiveness, it was impossible to recommend the use of milk to winegrowers," he recalls!
If using milk alone against powdery mildew is risky, can it at least be used as an adjuvant? This is the thesis defended by PierreHenri Dubuis, of Agroscope Changins, Switzerland. His trials, carried out in 2014 and 2015 with skimmed milk, showed that "milk makes the spray stick to the foliage, making it less susceptible to leaching.
It's this effect that's more interesting than the direct effect. As for the direct efficacy of milk, it is "small", according to this researcher, "of the order of 30 to 40% compared with a standard fungicide. So, in most cases, it's not enough to obtain a quality harvest".
In Champagne, Mr. Benoit MUNIER from Cuis (near Epernay), works his 1.6 hectares of vines in Viticulture Raisonnée. He tells us: "In 2019, the Champagne region suffered heavy attacks of powdery mildew, particularly on the Côte des Blancs. With sulfur, we had to really tighten up the cadences, the air was unbreathable, and it wasn't working. So I decided to try milk, coupled with garlic, at 8 l/ha, with 100 or 150 liters of water. You mustn't use too much to avoid developing other fungi.
Alternating with sulfur applications, this has enabled me to contain disease pressure. I'm also interested in milk, as we're increasingly confronted with scald problems linked to sulfur. Of course, there are other alternative products, but milk is a natural product."
We all drink it, it can't scare or hurt people, if it works, why not use it?
