Assessing the Impact of Water Stress on Neofusicoccum parvum in Table Grapes Using Proximal Sensing Technologies

Water availability represents a major limiting factor for crop production, particularly in Mediterranean agroecosystems. In parallel, water-stressed plants are often more susceptible to diseases, including Grapevine Trunk Diseases (GTDs), such as Botryosphaeria Dieback caused by Botryosphaeriaceae species. In Italy, the increasing prevalence of GTDs in young table grape plants and nursery material highlights the need to better understand the interaction between abiotic stress and pathogen dissemination in woody tissues. This study investigated the relationship between different water regimes (WRs) and infections by Neofusicoccum parvum. Grapevine cuttings (Vitis vinifera ‘Italia’ vines grafted onto the rootstock ‘140 Ruggeri’) were subjected to three WRs (20%, 50%, and 100% of crop evapotranspiration, ETc) under controlled environmental conditions and, subsequently, inoculated with mycelial plugs of N. parvum at both the scion and rootstock levels. Plant responses were monitored non-destructively using low-cost proximal sensing tools, including leaf temperature (Tleaf) and the Normalized Difference Vegetation Index (NDVI). Disease development was assessed by measuring internal necrotic lesion extension. Reduced irrigation was associated with increased disease severity, while proximal sensing detected differences in plant physiological responses among water regimes. Overall, the results highlight the interplay between water availability, plant physiological status, and disease severity under controlled conditions.