Water Stress Impacts on Grapevines (Vitis vinifera L.) in Hot Environments: Physiological and Spectral Responses

The projected increase in temperature and water scarcity represents a challenge for winegrowers due to changing climatic conditions. Although heat drought often occur concurrently nature, there is still little known about the effects of stress (WS) on grapevines hot environments. This study aimed assess whether grapevine’s physiological spectral responses WS environments differ from those expected under lower temperatures. Therefore, we propose an integrated approach physiological, thermal, response two grapevine varieties (Vitis vinifera L.), Grenache Shiraz, environment. In controlled environment room (CER), imposed high-temperature conditions (TMIN 30 °C–TMAX 40 °C) compared performance well-watered (WW) WS-ed potted own-rooted Shiraz (SH_WW, SH_WS, GR_WW, GR_WS, respectively). We monitored vines’ spectral, thermal trends imposition recovery after re-watering. Then, performed correlation analysis between parameters vegetation indices (VIs). Finally, looked best-fitting models predict based VIs. results showed that GR_WS was more negatively impacted than SH_WS terms net photosynthesis (Pn, GR-WS = 1.14 ?mol·CO2 m?2·s?1; SH-WS 3.64 m?2·s?1), leaf transpiration rate (E, 1.02 mmol·H2O 1.75 stomatal conductance (gs, 0.04 mol·H2O 0.11 m?2·s?1). intrinsic water-use efficiency (WUEi Pn/gs) (26.04 mol?1 H2O) (34.23 comparable SH_WW (26.31 H2O). not unaffected by except E. After stress, Pn, gs, E did recover, as they were significantly other treatments. anthocyanin Gitelson (AntGitelson) green normalised difference index (GNDVI) had significant negative correlations with stem potential (?stem), positive WUEi. contrast, photochemical reflectance (PRI), (WI), infrared (NDII) opposite trend. crop (CWSI) ?stem both varieties. Our findings help unravel behaviour vines suggest instrumental approaches managing abiotic stress.