Towards grapevine root architectural models to adapt viticulture to drought

Abstract

To sustainably adapt viticultural production to drought, the planting of rootstock genotypes adapted to a changing climate is a promising means. Rootstocks contribute to the regulation of scion vigor and water consumption, modulate scion phenological development and determine resource availability by root system architecture development. There is, however, a lack of knowledge on spatio-temporal root system development of rootstock genotypes and its interactions with environment and management that prevents efficient knowledge transfer into practice. Hence, winegrowers take only limited advantage of the large variability of existing rootstock genotypes. Models of vineyard water balance combined with root architectural models, using both static and dynamic representations of the root system, seem promising tools to match rootstock genotypes to frequently occurring future drought stress scenarios and address scientific knowledge gaps. In this perspective, we discuss how current developments in vineyard water balance modeling may provide the background for a better understanding of the interplay of rootstock genotypes, environment and management. We argue that root architecture traits are key drivers of this interplay, but our knowledge on rootstock architectures in the field remains limited both qualitatively and quantitatively. We propose phenotyping methods to help close current knowledge gaps and discuss approaches to integrate phenotyping data into different models to advance our understanding of rootstock x environment x management interactions and predict rootstock genotype performance in a changing climate. This could also provide a valuable basis for optimizing breeding efforts to develop new grapevine rootstock cultivars with optimal trait configurations for future growing conditions.

Keywords: plant architecture; root phenotypes; stress; sustainability; vineyard; water.

Figure 1

Example simulation of grapevine transpiration, evapotranspiration of cover cropped soil and evaporation of bare soil for three vineyards in the Rheingau region in 2022 (A–C). (A) Ehrenfels vineyard, row spacing 2.50 m, 85 mm available water capacity (AWC), fully cover cropped with exception of the undervine area (width 0.4 m). (B) Burgweg vineyard, row spacing 1.60 m, 115 mm AWC, every other row cover cropped. (C) Wilgert vineyard, row spacing 1.60 m, 320 mm AWC, fully cover cropped with exception of the undervine area. Development of cover crops is divided into several growth stages.