Multi-scale and multi-disciplinary approach to evaluate the mechanisms for leaf morpho-anatomical and eco-physiological acclimation of Greco grapevine under different canopy and soil management within the Italian GREASE project

In the Mediterranean region, climate models forecast an increase in temperature and irregularities in the precipitation patterns which are a challenge for viticulture. The number, type, intensity and duration of stressors induce specific morpho-physiological responses which are cultivar-specific and are reflected on grape yield and quality. A major challenge for vines in southern Mediterranean area is to invest resources to construct leaves capable of efficiently converting carbon into biomass, while controlling evapotranspiration losses, as well as maintaining a balance between vegetative growth and reproduction. Plants have to harmonize structure and function to achieve efficient physiological processes and use of resources. Although it is not clear whether plant anatomical structure is the bottleneck for efficient functioning or vice versa, it is recognized that tissue growth and photosynthesis cannot be decoupled. Therefore, the knowledge of the plasticity in the coordination between morpho-anatomical and eco-physiological traits in vines is needed to forecast how vineyards would respond to climate changes. Moreover, the impact of climate change depends on pedo-climatic spatial variability, and it can be either buffered or intensified by vineyard management.

Within this framework, the aim of this study was to evaluate the combined effect of two types of canopy management (double guyot and double guyot flipped) and three treatments of soil management (cover crops, natural coverage, and soil tillage) on the coordination of morpho-anatomical and eco-physiological traits in the grapevine cultivar 'Greco' (Vitis vinifera L. subsp. vinifera), autochthonous and widely cultivated in the Campania Region (southern Italy). The field trials were conducted at the Feudi di San Gregorio winery premises in southern Italy, within the GREASE project, funded by the Campania Region through the Rural Development Programme 2014-2020, with the general goal of improving grapevine productivity and resilience for the sustainable management of vineyards.

The status of vines was monitored over three years by applying a multidisciplinary approach allowing the analysis of vines behavior at the single plant- and whole-vineyard levels. Indeed, the growth and the eco-physiological traits of vines were monitored by measuring biometrical parameters, leaf gas-exchanges, chlorophyll a fluorescence emission, and leaf water potentials. Leaves were also sampled to quantify carbon stable isotopes as well as functional anatomical parameters (e.g. parenchyma, stomata and vein traits) linked to the efficiency of gas-exchanges and water flow. Proximal sensing techniques were applied to monitor the whole vineyard performances. The meteorological data and soil water content were collected through weather stations and time-domain reflectometry (TDR) technique.

The overall analysis of results showed that the effect of different canopy and soil management is strongly mediated by inter-and intra-annual variability of climatic factors. From a methodological point of view, the multidisciplinary approach proved to be fundamental to go in-depth in the cause-effect relations and mechanisms for vines acclimation. Only a deep understanding of such acclimation mechanisms can furnish the keys to optimize the utilization of the information collected through the novel proximal technologies, for the design of vineyard management strategies to improve yield and quality still assuring environmental sustainability.