Assessing the economic impacts of Flavescence Dorée management scenarios through a bioeconomic modelling approach

Flavescence dorée (FD) is one of the most damaging phytoplasma diseases affecting viticulture in Europe, caused by Candidatus Phytoplasma vitis and transmitted by the leafhopper Scaphoideus titanus. In the Veneto region, after a period of successful containment in the 1990s, the disease has undergone a significant recrudescence since 2019, prompting the regional administration to commission a feasibility study for a mutual fund dedicated to FD phytosanitary risk management. This thesis contributes to that framework through two complementary analyses. First, field monitoring data collected across 2.915 vineyard parcels over three consecutive years (2023–2025) were used to characterize the spatial and temporal distribution of FD damage frequency, damage entity, and composite risk across 172 municipalities and four major production areas of the Veneto region. Second, a bioeconomic modelling approach based on Partial Budget Analysis (PBA) was applied to quantify the economic impact of three alternative management scenarios: insecticide treatment with uprooting (MS1), insecticide treatment with uprooting and replanting (MS2), and unmanaged scenario (UNS); relative to a disease-free Baseline Scenario (BS), across four representative case studies: Prosecco DOC, C.V. Prosecco DOCG, Pinot Nero IGT and Merlot IGT. Monitoring results show an overall reduction in both damage frequency and entity between 2023 and 2025, suggesting that mandatory control measures are producing tangible effects at the aggregate level. However, the number of municipalities recording active FD infection increased from 114 to 156 over the study period, indicating a geographical redistribution of disease pressure rather than uniform regression, particularly concerning trends observed in the province of Venezia and the Prosecco DOC production area. The PBA results reveal a consistent economic hierarchy across all case studies: MS2 always produces the least negative cumulative NCI over the 20-year vineyard lifespan, followed by MS1, with UNS invariably generating the worst outcome. Cumulative losses under MS1 range from −€13,065 for Merlot IGT to −€184.946 for Prosecco DOC, while MS2 losses range from −€10,812 for Merlot IGT to −€137.654 for Prosecco DOC and UNS losses range from −€86,242 for Merlot IGT to −€277.524 for Prosecco DOC. A notable exception is observed in the Conegliano Valdobbiadene Prosecco DOCG case, where high per-plant management costs in hillside vineyards partially compress the economic distance between managed and unmanaged scenarios. These findings provide a quantitative basis for the design of a risk-differentiated contribution structure within the proposed mutual fund and offer strong economic justification for the mandatory phytosanitary management measures currently enforced in the Veneto region.