The Organic Way of Managing Powdery Mildew

In my 17 years in Umbria, our wettest months have been November, and then March, April and May, in that order. If the wet weather spills into June, then disease management in the Vineyards of Chiesa del Carmine becomes more difficult. Vine disease doesn’t care if you treat your vineyard in an organic, conventional or integrated way. The only certainty is that it will be present, regardless of circumstances. Conventional growers use systemic fungicides to combat vineyard disease while organic producers have to search for more environmentally friendly solutions.

Powdery mildew is probably one of the most serious grapevine fungal disease worldwide. This disease appears as a whitish-grey powdery coating on the leaves or fruit or on the freen surface of the plant. Berry infection may lead to further infection that reduces the quality of wine, even if the powdery mildew infection is mild because the skin is compromised. It is present in almost every vineyard and represents the biggest challenge for organic wine producers to fight with.

Here is what we do to successfully manage this problem. The environment is the first aspect to take into consideration. A wet June, as Umbria has experienced this year, with 150mls to date in our valley, means we need to be on the top of our game. We have worked hard to make green management in time, strict shoot selection and mostly a good work on the bunch zone, removing lateral shoots and leaves as much as needed. This also improves spray application efficiency and distribution throughout the canopy.

When first infections come, we check if flag shoots or primary infections on the young leaves are present. Then we implement a strict spray program using different kinds of Sulphur: a good application is the key to succeed. Late this week we will make our fourth treatment of 2020.

Fighting Powdery mildew in an organic way is not easy. We constantly watch the weather and check on the vineyard but we feel the results and the quality of our wines, validate the effort and we know that if the season is favourable, we will have done everything in our power produce great fruit which is the only way to produce great wines. We will also have done the right thing by the environment.