Influenza dell’esposizione del vigneto sulla maturazione dell’uva

Abstract

[English version below]

Lo studio è stato condotto in vigneti commerciali di Vitis vinifera cv Nebbiolo localizzati in Piemonte, Italia del Nord-Ovest, intorno alla sommità di una collina. L’obiettivo dello studio è stato di determinare come l’esposizione del vigneto possa influenzare il comportamento vegetativo della vite, il manifestarsi delle fasi fenologiche, e la cinetica di maturazione dell’uva con particolare riguardo all’accumulo di antociani e flavonoli. Le esposizioni più meridionali hanno indotto precocità di germogliamento e fioritura ma diminuzione della fertilità per gemma e, di conseguenza, della resa per pianta influenzando anche il peso dei grappoli, degli acini e delle bucce; hanno promosso una maggiore concentrazione dei solidi solubili nelle ultime fasi di maturazione ma la sintesi degli antociani e dei flavonoli ha subito un rallentamento durante le fasi tardive di maturazione. L’esposizione occidentale ha favorito il ritardo delle fasi fenologiche e un aumento della fertilità per gemma, del peso del grappolo e della resa produttiva, determinando un minore accumulo di solidi solubili nel mosto ma una maggiore sintesi di antociani. Si è evidenziata, in oltre, una probabile influenza della temperatura non solo sulla sintesi degli antociani ma anche dei flavonoli delle bucce.

The study was conducted in Sinio (Piedmont, Northwest Italy) in commercial vineyards of Vitis vinifera cv. Nebbiolo, situated on the top of a 30 % slope hillside, thus they were differently exposed: two of these (A) was exposed to South, another (B) to East-South-East, the fourth (C) to West-North-West. The clone CVT 141 grafted onto 420 A, was cultivated in every vineyard. Vines were VSP trained and pruned to the Guyot system (10 bud cane plus 2 bud spur). Vine theoretical density was 5200 vine/ha. The aim of this study was to determine how the vineyard exposition influences vine vegetative behaviour, phenological phase timing, grape ripening kinetic and grape properties including colour and flavonols. The results were used to characterize the vineyards in a sort of farm zoning, helping to choose the best technical management.
The 2009 vintage was characterized by a very rainy winter and spring, and a very hot summer (from mid July until the beginning of September the maximum temperature, as average, exceeded 32 °C). Bud burst and flowering resulted delayed in C, respect to A and B vineyards, whereas bud fertility was higher in C. That fact induced a higher bunch weight (313 g) in vineyard facing West (C), respect to those Southward (A and D) where bunch weight was similar (224 g) also thanks to a higher berry mass (1.87 g in A and D, 2.09 g in B, and 2.07 g in C). Furthermore, vineyard exposition influenced the vine vigour and yield that in C and D were twice that in A and B vineyards. Soluble solid content at harvest appeared higher in A, B and D (24.3 Brix as average) than in C vineyard (23.7 Brix). Southern expositions (A and D) delayed the beginning of veraison and reduced the anthocyanin concentration at harvest (600 mg/kg) respect to B (670 mg/kg) and C (770 mg/k); further differences among vineyards were observed both in the pattern of flavonol accumulation and in their concentration at harvest. In synthesis the Southern expositions advanced the phenological phases and decreased bud fertility, yield per vine and weight of bunches, berries and berry skins. In addition, it promoted a high concentration of soluble solids at harvest but not of anthocyanins whose concentration slowed down during the late phases of ripening. Western exposition (C) promoted a delay of phenological phases, and an increase of bud fertility, bunch weight and yield per vine; it induced a medium accumulation of soluble solids but the highest synthesis of anthocyanins. Due to the global warming we can expect a high variability between vintages from a weather point of view. We think that a sort of farm zoning matched with data obtained from observations executed in successive vintages could be a useful help to choose the best technical management for a specific year and to foresee in advance the vintage results.

DOI:

Publication date: December 3, 2021

Issue: Terroir 2010

Type: Article

Authors

Guidoni S., Gangemi L., Ferrandino A.

Dipartimento di Colture Arboree, Università di Torino, Via L. Da Vinci, 44. 10095 Grugliasco (TO), Italy

Contact the author

Keywords

Nebbiolo, fasi fenologiche, produttività, antociani, flavonoli
Nebbiolo, phenological phases, yield, anthocyanins, flavonols

Tags

IVES Conference Series | Terroir 2010

Citation

Related articles…

Bioclimatic shifts and land use options for Viticulture in Portugal

Land use, plays a relevant role in the climatic system. It endows means for agriculture practices thus contributing to the food supply. Since climate and land are closely intertwined through multiple interface processes, climate change may lead to significant impacts in land use. In this study, 1-km observational gridded datasets are used to assess changes in the Köppen–Geiger and Worldwide Bioclimatic (WBCS)

Climate, Viticulture, and Wine … my how things have changed!

The planet is warmer than at any time in our recorded past and increasing greenhouse emissions and persistence in the climate system means that continued warming is highly likely. Climate change has already altered the basic framework of growing grapes for wine production worldwide and will likely continue to do so for years to come. The wine sector can continue to play an important role in leading the agricultural sector in addressing climate change. From developing on…

Spatial determination of areas in the Western Balkans region favorable for organic production

In problematic conditions for production of grapes and wine caused by the COVID-19 pandemic and the resulting occurrence of wine surpluses, producers are increasingly turning to the innovative viticulture and winemaking of products that are more appealing to the market and the consumers. On the other hand, consumption of the food safety or organic products, and therefore of organic grapes and wine, is increasingly common in the world, in particular in Europe. The Regional Rural Development Standing Working Group (SWG RRD), as a regional intergovernmental organization gathers actors in the viticulture and winemaking sector from states and territories of the Western Balkans (South-East Europe) in the Expert Working Group for Wine, with the aim of improving viticulture and winemaking in this region through joint activities. In accordance with the aforementioned, the SWG RRD is working on advancing organic production of grapes and wine, and on recognition of specificities of the terroir of wine-growing areas in Western Balkans. In addition, as part of the project “Facilitation of Exchange and Advice on Wine Regulations in Western Balkan Countries” helmed by the German Federal Ministry of Food and Agriculture, in addition to harmonization of relevant legislation with EU regulations, efforts are being invested towards recognition of organic wines. Within activities and project implemented by this organization, expert analyses and scientific research of the terroir of Western Balkans were carried out, and some of the results are presented in this paper.

An analytical framework to site-specifically study climate influence on grapevine involving the functional and Bayesian exploration of farm data time series synchronized using an eGDD thermal index

Climate influence on grapevine physiology is prevalent and this influence is only expected to increase with climate change. Although governed by a general determinism, climate influence on grapevine physiology may present variations according to the terroir. In addition, these site-specific differences are likely to be enhanced when climate influence is studied using farm data. Indeed, farm data integrate additional sources of variation such as a varying representativity of the conditions actually experienced in the field. Nevertheless, there is a real challenge in valuing farm data to enable grape growers to understand their own terroir and consequently adapt their practices to the local conditions. In such a context, this article proposes a framework to site-specifically study climate influence on grapevine physiology using farm data. It focuses on improving the analysis of time series of weather data. The analytical framework includes the synchronization of time series using site-specific thermal indices computed with an original method called Extended Growing Degree Days (eGDD). Synchronized time series are then analyzed using a Bayesian functional Linear regression with Sparse Steps functions (BLiSS) in order to detect site-specific periods of strong climate influence on yield development. The article focuses on temperature and rain influence on grape yield development as a case study. It uses data from three commercial vineyards respectively situated in the Bordeaux region (France), California (USA) and Israel. For all vineyards, common periods of climate influence on yield development were found. They corresponded to already known periods, for example around veraison of the year before harvest. However, the periods differed in their precise timing (e.g. before, around or after veraison), duration and correlation direction with yield. Other periods were found for only one or two vineyards and/or were not referred to in literature, for example during the winter before harvest.

Using δ13C and hydroscapes as a tool for discriminating cultivar specific drought response

Measurement of carbon isotope discrimination in berry juice sugars at maturity (δ13C) provides an integrated assessment of water use efficiency (WUE) during the period of berry ripening, and when collected over multiple seasons can be used as an indication of drought stress response. Berry juice δ13C measurements were carried out on 48 different varieties planted in a common garden experiment in Bordeaux, France from 2014 through 2021 and were paired with midday and predawn leaf water potential measurements on the same vines in a subset of six varieties. The aim was to discriminate a large panel of varieties based on their stomatal behaviour and potentially identify hydraulic traits characterizing drought tolerance by comparing δ13C and hydroscapes (the visualisation of plant stomatal behaviour as a response to predawn water potential). Cluster analysis found that δ13C values are likely affected by the differing phenology of each variety, resulting in berry ripening of different varieties taking place under different stress conditions within the same year. We accounted for these phenological differences and found that cluster analysis based on specific δ13C metrics created a classification of varieties that corresponds well to our current empirical understanding of their relative drought tolerances. In addition, we analysed the water potential regulation of the subset of six varieties (using the hydroscape approach) and found that it was well correlated with some δ13C metrics. Surprisingly, a variety’s water potential regulation (specifically its minimum critical leaf water potential under water deficit) was strongly correlated to δ13C values under well-watered conditions, suggesting that base WUE may have a stronger impact on drought tolerance than WUE under water deficit. These results give strong insights on the innate WUE of a very large panel of varieties and suggest that studies of drought tolerance should include traits expressed under non-limiting conditions.