Charentes Winegrowers Face Rising Mildew Risk

French winegrowers in the Charentes region are being warned to watch closely for the first signs of downy mildew after the latest plant health bulletin reported early spots in vineyards and a high to very high risk of black rot, at a stage when Ugni Blanc vines are still at clustered flower buds.

The bulletin, issued May 5 by the regional viticulture network, said the average growth stage for Ugni Blanc is 15, with flower buds still tightly grouped. That timing matters because it shapes how growers decide whether and when to treat vines. The report said downy mildew has now appeared in the vineyard, but infections remain limited and localized. Even so, the bulletin urged vigilance because weather conditions and vine development can quickly change the situation.

Black rot is the main concern in this issue. The bulletin rated the risk of contamination as high to very high, a level that can push growers to act early to protect young tissue before disease spreads. Oidium, or powdery mildew, was assessed differently: most Ugni Blanc vines in the area have not yet reached the stage of sensitivity, and the risk of contamination was described as low for now.

The bulletin also noted continued flight activity from Eudémis, a grapevine moth that can damage clusters later in the season. Monitoring that pest remains part of the broader effort to manage vineyard health across Charentes, where growers rely on regular field observations to guide treatment decisions and limit unnecessary spraying.

The regional bulletin is part of France’s plant health monitoring system, known as BSV, which provides near real-time information on crop conditions and regulatory guidance. It is designed to help winegrowers adjust their phytosanitary strategy based on observed disease pressure rather than calendar dates alone. Officials said the quality of the data depends heavily on the size and reliability of the observation network in the Charentes vineyards, and they encouraged growers to keep reporting disease outbreaks, pests and weather events through Alerte Vigne throughout the season.

For producers in a region where vine health can affect both yields and costs early in the campaign, the latest report signals a critical period of close surveillance as spring advances and disease pressure begins to build.