Water deficit responses of field-grown Pinot noir mediated by rootstock genotypes in a cool climate region

Under the global warming scenario, water scarcity is expected to intensify in most grape-growing regions. The use of drought-tolerant rootstocks considered a useful tool mitigate negative effects soil deficit on vine functioning. Differences leaf gas exchange, plant status, specific hydraulic conductivity petioles (Kpetiole), xylem vessel size and vegetative vigour field-grown Pinot noir grafted onto five (3309C, 101-14 MGt, Kober 5BB, Riparia Gloire de Montpellier, 41B MGt) were investigated during one season under Switzerland. was imposed by installing waterproof non-reflecting plastic sheets from March harvest (September) avoid rainfall infiltration. Rootstocks had stronger status than exchanges. During grape ripening stage, vines MGt characterised more severe stress as shown lowest values pre-dawn (Ψpd), stem potential (Ψstem) integral (SΨ), whereas 3309C 5BB induced milder effects. Significant differences photosynthesis (A), stomatal conductance (gs) transpiration (E) only observed between at later stages ripening. Changes shoot vigour, Kpetiole number vessels stems correlated differential responses deficit. increased associated with highest Kpetiole, good low availability. yield, probably due better showed malic acid content yeast assimilable nitrogen berries.