Towards adaption to free air carbon dioxide enrichment (FACE): preliminary results on physiology of Vitis vinifera L. cv Riesling

Abstract

As the concentration of atmospheric carbon dioxide (CO₂) is steadily increasing this will have considerably effects on agricultural crops including viticulture. To examine plant responses at future CO₂ concentrations under field conditions an open “Free Air Carbon dioxide Enrichment” (FACE) facility for special crops (viticulture and vegetables) was setup in 2012. The corresponding grapevine FACE site is located at Geisenheim (50°N, 8°E, Germany) and was planted as a vineyard ring design including two Vitis vinifera L. cultivars (Riesling and Cabernet Sauvignon). Carbon dioxide concentrations predicted for 2050 (according to the IPCC 2013) were assessed and compared to present atmospheric CO₂-conditions.

For this study field experiments were conducted on Vitis vinifera L. cv. Riesling (clone 198-30 Gm) grafted on rootstock SO4 (clone 47 Gm) to investigate effects of elevated CO₂ concentrations on grapevine physiology.

First results showed higher net assimilation and transpiration rates during vegetation period in 2014 for CO₂ enhanced Riesling grapevines. Differences between treatments due to water use efficiency (WUE), calculated on net assimilation rate in relation to stomatal conductance were determined for several stages over the growing season. Observed results of changes in the adaptation of the source/sink ratio under an increased CO₂ level supplied first steps towards an understanding of impacts on growth parameters.