The devastating arrival of downy and powdery mildew in the vineyards

The 19th century marked an unprecedented upheaval for European viticulture. Following powdery mildew in 1851, downy mildew arrived in 1878, followed by black rot in 1886. These fungal diseases, originating from America, had devastating consequences on vineyards, profoundly altering local varietal mixes and forcing winegrowers to find solutions to protect their harvests. Phylloxera, which arrived earlier in 1863, had an even greater impact, leading to the massive use of rootstocks derived from American Vitis species.

Variable tolerance within Vitis vinifera and the emergence of resistant grape varieties

Faced with these scourges, Vitis vinifera, the species from which the classic grape varieties originate, lacks complete natural resistance to downy and powdery mildew. However, certain varieties display a greater or lesser tolerance to these diseases. This observation paved the way for the search for new varieties. Beyond intrinsic tolerances, breeding resistant varieties has become a necessity, significantly reducing the use of plant protection products. These varietal innovations are crucial for the future of viticulture in the face of environmental and economic challenges. To learn more about these efforts, discover resistant grape varieties in Bordeaux.

How are disease-resistant varieties developed?

Breeding vine varieties resistant to diseases such as downy and powdery mildew is the result of intensive selection and hybridisation programmes. This work, initiated in the 19th century, involves crossing Vitis vinifera with wild American or Asian Vitis species that are naturally resistant to pathogens. These successive crosses allow resistance genes to be transferred while retaining the oenological qualities of cultivated varieties. This long and meticulous process is essential for developing sustainable solutions for winegrowers. To understand the different terms, see our glossary of resistant, tolerant, hybrid and PIWI grape varieties. The journey of a new variety towards inclusion in the official catalogue is complex, as explained in our article on the classification of varieties in the official catalogue.

Advancements in resistant grape varieties and their agronomic implications

Recent progress in breeding resistant grape varieties has been remarkable. These new varieties make it possible to significantly reduce the number of required fungicide sprayings, directly influencing the estate's Treatment Frequency Index (TFI). In viticulture, this index varies widely across regions and accounts for up to 30% of fungicides used in France. Fewer treatments mean better vineyard labour management, reduced costs and a lower environmental impact. However, managing the risk of pathogens overcoming these resistances remains a challenge. Grape varieties such as Arinarnoa or Marselan are examples of new varieties authorised for adapting to climate change and reducing inputs. Discover also the latest developments regarding Bouquet 3159-2-12 B (Chasan offspring), as well as the promising Bouquet 3179-90-7 N (Grenache offspring), another innovation. To learn more about the testing frameworks that validated these innovations, discover Oscar Oc: the framework that validated Bouquet varieties.

Château Cazebonne is committed to preserving biodiversity and reintroducing forgotten grape varieties, thereby contributing to the future of the Bordeaux vineyards. This work is made possible through the support of wine enthusiasts who embrace our wines. To learn more about our approach and the history of the vineyards, you can download our book "Bordeaux, une histoire de cépages". Test your knowledge and explore the world of wine with our wine quizzes, or browse our wines online directly and support our commitment.