Effects of grapevine variety, leaf position and vigour on stomatal conductance. A seasonal assessment of water stress tolerance under climate change

This thesis aims to comprehensively explain the physiological growth cycle of Chardonnay grapevine as well as three other reference varieties such as Semillon, Merlot and Tinto Cao. Using weekly stomatal conductance measurements of leaf physiology from berry set to senescence with the help of the LI-600 porometer and fluorometer. The study was carried out on the grapevines of the 52 varieties included in the VitAdapt plot; an experimental vineyard that was set up in Bordeaux in 2009 in order to study the response of a wide range of grape varieties to climate change. Throughout the study, detailed phenological monitoring and weekly analysis of grape composition was conducted, the key elements to be studied on these grapevines will be stomatal conductance, transpiration rates and photosynthesis efficiency as well as enable us to understand the timeline of decrease of stomatal conductance in relation to leaf color change and leaf fall. This research will enable us to better understand the dynamic changes that occur throughout the grapevine cycle. By studying these physiological processes, we were able to understand and uncover how grapevines react to micro-climate, soil, water stress and environmental changes such as climate change and see how these affect their growth, development and overall productivity in the winemaking as well as compare them to each other. As a result…