Bordeaux vintners face off against mildew and excoriose

In the heart of Bordeaux, a renowned wine region that captivates connoisseurs and casual drinkers alike with its deep ruby reds and crisp, complex whites, the 2024 vintage faces a formidable challenge. The vines, with their lush leaves unfurling in the spring air, are under the microscopic siege of mildew spores and the threat of excoriose, painting a tense scene in this storied landscape.

The drama began to unfold last week when only the mildew eggs, meticulously buried in the soil at Villenave-d'Ornon and incubated by the Regional Federation for the Fight and Defense Against Harmful Organisms (Fredon), showed signs of germination within 24 hours. Their counterparts in Pompignac, Montagne, and Parempuyre, however, remained dormant. Encouraged by these findings and predictive models from the French Vine and Wine Institute (IFV), the Bulletin de Santé du Végétal (BSV) confidently assessed the mildew risk as "none," except for those vineyards ahead of their growth schedule and only if substantial rain fell by week's end.

Tristan des Ordons, of the agricultural consulting firm Phloème, criticizes this assessment as overly optimistic. He points out that many plots in Médoc and Entre-deux-Mers received such heavy rainfall in March that they are still damp or even inaccessible, challenging the notion of a nonexistent risk. According to des Ordons, the combination of warm soils and vines already displaying 2-3 leaves significantly elevates the risk of mildew, especially after primary contaminations were observed in puddles.

Moreover, the scant rainfall from Sunday night into Monday likely propelled the spores onto the vine leaves, creating ideal conditions for mildew's proliferation. Des Ordons emphasizes the missed opportunity for organic vineyards to apply their first treatment before this rainfall, a critical step in preemptive disease management.

The wisdom of staying ahead of the weather, as echoed by David Pernet, another viticulture expert, underscores the importance of proactive treatments. The early bud break this year, accompanied by the premature maturity of mildew spores, follows a predictable yet challenging pattern for vineyard managers. Pernet also highlights the conducive climate for the development of excoriose, a fungal disease that left unchecked, can ravage grapevines. He notes that some growers have already taken preventative measures to shield their vines, particularly those in parcels previously afflicted by excoriose.

This year's climatic conditions in Bordeaux have thus set the stage for a meticulous battle between vintners and vine diseases. The stakes are high, as the outcome will undoubtedly influence the quality and quantity of the 2024 vintage. Growers must navigate the delicate balance between traditional wisdom and innovative agricultural practices, all while the unpredictable whims of nature loom large. As they tend to their vines with a mix of anxiety and hope, the broader wine community watches on, eager to see whether the 2024 vintage will emerge triumphantly or bear the scars of this early challenge.