Giesco
PHYSIOLOGICAL AND YIELD PERFORMANCE OF VITIS VINIFERA L. CVS. (RIESLING AND CABERNET SAUVIGNON) UNDER FREE AIR CARBON DIOXIDE ENRICHMENT (FACE) RENDIMIENTO FISIOLÓGICO Y PRODUCTIVO DE VITIS VINIFERA L. CVS. (RIESLING Y CABERNET SAUVIGNON) BAJO ENRIQUECIMIENTO CON DIOXIDO DE CARBONO LIBRE DE AIRE (FACE)
WOHLFAHRT, Yvette*; TITTMANN, Susanne; STOLL, Manfred Hochschule Geisenheim University, Department of General and Organic Viticulture, Von-Lade-Str. 1, 65366 Geisenheim, Germany *Corresponding author: Tel.: +49 6722 502-144, yvette.wohlfahrt@hs-gm.de
Abstract: Two main challenges of a changing climate are the increase in atmospheric carbon dioxide (CO2) and temperature in relation to physiological responses and yield performance of plants. To investigate responses of field grown grapevines under elevated CO2 (+20 %) conditions a FACE (Free Air Carbon dioxide Enrichment) facility for Vitis vinifera cvs. Riesling and Cabernet Sauvignon was established at Geisenheim (50°N, 8°E, Germany) in 2012. Since 2014 vines have been exposed for three consecutive years to either ambient (aCO2 at 400 ppm) or elevated (eCO2 at 480 to 500 ppm) CO2 conditions from sunrise to sunset. Physiological measurements were mainly based on leaf gas exchange measurements during the vegetation periods, whereas grapevine yield parameters were examined during berry development and harvest stage. Results showed higher net assimilation rates and alterations in transpiration and stomatal conductance during the three vegetation periods for eCO2 grapevines and both cultivars. Differences between treatments due to intrinsic water use efficiency (WUEi) and pre-dawn leaf water potential (Øpd) showed improved efficiency for eCO2 plants. Independent of variety eCO2 grapevines showed higher single grapevine yield overall three vintages but no differences in number of bunches per vine. Assessment of grape bunches indicated higher single berry weight and modification in bunch architecture of both cultivars under eCO2. The observed multi-seasonal effects of eCO2 on grapevines regarding physiology and yield performance confirm the sensibility of perennial plants to a changing climate and could lead to changes in grape and wine composition.
Keywords: Carbon Dioxide (CO2), FACE, Vitis vinifera, physiology, yield, Riesling, Cabernet Sauvignon
Abstract: Two main challenges of a changing climate are the increase in atmospheric carbon dioxide (CO2) and temperature in relation to physiological responses and yield performance of plants. To investigate responses of field grown grapevines under elevated CO2 (+20 %) conditions a FACE (Free Air Carbon dioxide Enrichment) facility for Vitis vinifera cvs. Riesling and Cabernet Sauvignon was established at Geisenheim (50°N, 8°E, Germany) in 2012. Since 2014 vines have been exposed for three consecutive years to either ambient (aCO2 at 400 ppm) or elevated (eCO2 at 480 to 500 ppm) CO2 conditions from sunrise to sunset. Physiological measurements were mainly based on leaf gas exchange measurements during the vegetation periods, whereas grapevine yield parameters were examined during berry development and harvest stage. Results showed higher net assimilation rates and alterations in transpiration and stomatal conductance during the three vegetation periods for eCO2 grapevines and both cultivars. Differences between treatments due to intrinsic water use efficiency (WUEi) and pre-dawn leaf water potential (Øpd) showed improved efficiency for eCO2 plants. Independent of variety eCO2 grapevines showed higher single grapevine yield overall three vintages but no differences in number of bunches per vine. Assessment of grape bunches indicated higher single berry weight and modification in bunch architecture of both cultivars under eCO2. The observed multi-seasonal effects of eCO2 on grapevines regarding physiology and yield performance confirm the sensibility of perennial plants to a changing climate and could lead to changes in grape and wine composition.
Keywords: Carbon Dioxide (CO2), FACE, Vitis vinifera, physiology, yield, Riesling, Cabernet Sauvignon