Response of Chardonnay B. grapevines to weak to moderate water deficit: vine growth and must composition

Abstract

Vine water status is a key factor in terroir which plays major role in the culture and the economy of Burgundy. To gain further insight of the relationships between water status, vine growth and enological potentialities of Vitis vinifera cv Chardonnay B, an irrigation survey has been led on a plot of an experimental vineyard in Burgundy during three vintages (2011, 2013 and 2014). Three types of water deficit treatments DRY, MOD and WET were applied to the vines, thanks to water-proof plastic placed on the ground and a drip irrigation device.

Grapevine water status was simulated by means of the grapevine water balance model of Lebon et al. (2003), which was used to control the irrigation treatments. Vine water status was monitored by surveying leaf stem and predawn water potentials, and δ¹³C analysis of grape juice at harvest. Soil volumetric humidity was recorded by means of both TDR probes and electrical resistivity tomography (ERT).

During the three years of monitoring, grapevines experienced low to moderate water deficit, according to the vintage and the irrigation treatment. Severe water deficit was never reached, probably because of both insufficient evaporative demand and presence of in-depth water. Vine growth was not significantly affected for the water deficit reached, neither were grape sugar content and acidity.  Glycoconjugate  aroma  precursors  must  content  showed  no  clear  differences  between  the  treatments. This study suggest that low to moderate water deficit, as commonly experienced in Burgundy vintages/terroirs, seem to have minor effect on grape oenological potentialities.