{"id":"acta_495","title":"Effects of high spring rainfall on downy mildew and grapevine yield in France","year":2025,"publisher":"ACTA","excerpt":"Precipitation in spring is a critical driver of both grapevine development and fungal disease dynamics. This study quantifies the impact of high spring precipitation on downy mildew (Plasmopara viticola) and grapevine yield. Using French data from 2002 to 2023, we apply a causal inference framework …","url":"https://rd-agri.fr/detail/DOCUMENT/acta_495","links":{"self":"/rd-agri/documents/acta_495"},"description":"Precipitation in spring is a critical driver of both grapevine development and fungal disease dynamics. This study quantifies the impact of high spring precipitation on downy mildew (Plasmopara viticola) and grapevine yield. Using French data from 2002 to 2023, we apply a causal inference framework to disentangle the relationship between spring precipitation, disease, and yield loss. Using a double robust statistical method, we estimate that high precipitation in May (above the 80th percentile) reduces yield on average by –8.69% [–11.51%, –5.49%] and increases both foliar downy mildew incidence and severity by 5.07% [2.42%, 8.39%] and 2.75% [0.66%, 4.75%], respectively. Estimated values were similar whether derived from linear models or from a more flexible gradient boosting machine learning algorithm, indicating a high degree of robustness of the results to model specification. We found significant negative effects of disease incidence and severity on yields, but these effects became non-significant when precipitation was taken into account, suggesting that the effects of high disease incidence and high precipitation are partly intertwined. These findings confirm that spring precipitation can reduce grapevine yield and that this negative effect is at least partly due to an increased downy mildew development in grapevine leaves.","language":"eng","keywords":[],"project":{"code":"25PIT201","name":"Programme transversal 2025 « Mobilisation du levier du numérique pour soutenir la conception, le pilotage, le déploiement et la valorisation de systèmes de production agricole innovants et performants »"},"notice-url":"https://papers.ssrn.com/sol3/papers.cfm?abstract_id=5429516","document-url":"https://papers.ssrn.com/sol3/papers.cfm?abstract_id=5429516","productions":[],"taxa":[],"production-systems":[],"areas":[],"pests":[]}