Vineyard design and plant material choices effect on grapevine yield: analysis of a big dataset in the south of France

International audience

anglais. Strategic design decisions regarding wine label, plant material, vine age renewal, and planting choices are crucial for winegrowers when planning their future vineyards that will influence grapevine yield in the long term. However, the repercussions of these choices have mostly been studied in experimental vineyards and small datasets. Therefore, we are missing a comprehensive analysis of a large diversity of vineyard situations that can robustly provide avenues for improving vineyard design and ensure sustainable wine production. To fill this research gap, we analyzed a big sample of vineyards using random plot data (n = 3507) from surveys conducted among winegrowers of the Languedoc-Roussillon viticultural region. We carried out a data analysis that focused on examining the relationship between grapevine yield and (i) diverse vineyard management frameworks (wine label, organic management, irrigation), (ii) plant material (varieties, rootstocks), and (iii) planting choices (planting density, vine age as a proxy for vine lifespan and renewal). Our findings indicate that wine label greatly affected yield; in conjunction with vine age, they explained up to 40% of the total yield variance. Most cultivated varieties exhibited similar yield levels for the same type of wine label. Notably, SO4 rootstock displayed the best yield performance across multiple cultivated varieties. We observed an adverse effect of vine aging on grapevine yield, particularly in highly productive vineyards. In contrast, the impact of vine age on the yield of low-yield plots was almost negligible. Plots under organic farming presented lower yields, although they were scarce in the sample. Unexpectedly, planting density did not significantly affect yield. Overall, these results underscore the significance of conducting big data analysis from winegrowers at a regional level, when it comes to assessing the influence of vineyard design and plant material on yield.