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…

Influence of a spontaneous cover crop on the vineyard and soil erosion under Mediterranean climate

Sixty five % of the agricultural area of the Basque Country located in the DO Ca Rioja corresponds to vineyards. More than 40% of it has an average slope greater than 10%, which makes it sensitive to erosive processes. Furthermore, it is foreseeable that extreme weather events (storms, hail, extreme heat and cold, etc.) will be favored due to climate change. Cover cropping can mitigate this risk, and therefore the objective of this work is to evaluate the impact that a vegetable cover has on the agronomic behavior of the vineyard, the quality of the grape and soil erosion. For this, a trial has been carried out with a Graciano variety vineyard with a slope between 10% -20% during the years 2020 and 2021. Conventional tillage management in the area has been compared (4-6 passes per year of tillage machinery) versus spontaneous vegetation cover management in the vineyard. This implies not tilling and allowing the grass of the land to colonize the range between the lines of vines, controlling their height through 1-3 mowing passes per year, always trying to affect the surface of the land as little as possible. The vegetative growth, yield and quality of the grape and wine was measured. Furthermore, erosion has been measured using Gerlasch boxes. The yield was lower in the second year of the trial in the cover crop treatment, but erosion was significantly reduced.

Impact of climate variability and change on grape yield in Italy

Viticulture is entangled with weather and climate. Therefore, areas currently suitable for grape production can be challenged by climate change. Winegrowers in Italy already experiences the effect of climate change, especially in the form of warmer growing season, more frequent drought periods, and increased frequency of weather extremes.
The aim of this study is to investigate the impact of climate variability and change on grape yield in Italy to provide winegrowers the information needed to make their business more sustainable and resilient to climate change. We computed a specific range of bioclimatic indices, selected by the International Organisation of Vine and Wine (OIV), and correlated them to grape yield data. We have worked in collaboration with some wine consortiums in northern and central Italy, which provided grape yield data for our analysis.
Using climate variables from the E-OBS dataset we investigate how the bioclimatic indices changed in the past, and the impact of this change on grape productivity in the study areas. The climate impact on productivity is also investigated by using high-resolution convection-permitting models (CPMs – 2.2 horizontal resolution), with the purpose of estimating productivity in future emission scenarios. The CPMs are likely the best available option for this kind of impact studies since they allow a better representation of small-scale processes and features, explicitly resolve deep convection, and show an improved representation of extremes. In our study, we also compare CPMs with regional climate models (RCMs – 12 km horizontal resolution) to assess the added value of high-resolution models for impact studies. Further development of our study will lead to assessing the future suitability for vine cultivation and could lead to the construction of a statistical model for future projection of grape yield.

Biodiversity in the vineyard agroecosystem: exploring systemic approaches

Biodiversity conservation and restoration are essential for guarantee the provision of ecosystem services associated to vineyard agroecosystem such as climate regulation trough carbon sequestration and control of pests and diseases. Most of published research dealing with the complexity of the vineyard agroecosystems emphasizes the necessity of innovative approaches, including the integration of information at different temporal and spatial scales and development of systemic analysis based on modelling. A biodiversity survey was conducted in the Franciacorta wine-growing area (Lombardy, Italy), one of the most important Italian wine-growing regions for sparkling wine production, considering a portion of the territory of 112 ha. The area was divided into several Environmental Units (EUs), defined as a whole vineyard or portion of vineyard homogenous in terms of four agronomic characteristics: planting year, planting density, cultivar, and training system. In each EU a set of compartments was identified and characterised by specific variables. The compartments are meteorology, morphology (altitude, slope, aspect, row orientation, and solar irradiance), ecological infrastructures and management. The landscape surrounding EU was also characterised in terms of land-use in a buffer zone of 500 m. For each component a specific methodology was identified and applied. Different statistical approaches were used to evaluate the method to integrate the information related to different compartments within the EU and related to the buffer zone. These approaches were also preliminarily evaluated for their ability to describe the contribution of biodiversity and landscape components to ecosystem services. This methodological exploration provides useful indication for the development of a fully systemic approach to structural and functional biodiversity in vineyard agroecosystems, contributing to promote a multifunctional perspective for the all wine-growing sector.

Variety and climatic effects on quality scores in the Western US winegrowing regions

Wine quality is strongly linked to climate. Quality scores are often driven by climate variation across different winegrowing regions and years, but also influenced by other aspects of terroir, including variety. While recent work has looked at the relationship between quality scores and climate across many European regions, less work has examined New World winegrowing regions. Here we used scores from three major rating systems (Wine Advocate, Wine Enthusiast and Wine Spectator) combined with daily climate and phenology data to understand what drives variation across wine quality scores in major regions of the Western US, including regions in California, Oregon and Washington. We examined effects of variety, region, and in what phenological period climate was most predictive of quality. As in other studies, we found climate, based mainly on growing degree day (GDD) models, was generally associated with quality—with higher GDD associated with higher scores—but variety and region also had strong effects. Effects of region were generally stronger than variety. Certain varieties received the highest scores in only some areas, while other varieties (e.g., Merlot) generally scored lower across regions. Across phenological stages, GDD during budbreak was often most strongly associated with quality. Our results support other studies that warmer periods generally drive high quality wines, but highlight how much region and variety drive variation in scores outside of climate.

Grapevine sugar concentration model in the Douro Superior, Portugal

Increasingly warm and dry climate conditions are challenging the viticulture and winemaking sector. Digital technologies and crop modelling bear the promise to provide practical answers to those challenges. As viticultural activities strongly depend on harvest date, its early prediction is particularly important, since the success of winemaking practices largely depends upon this key event, which should be based on an accurate and advanced plan of the annual cycle. Herein, we demonstrate the creation of modelling tools to assess grape ripeness, through sugar concentration monitoring. The study area, the Portuguese Côa valley wine region, represents an important terroir in the “Douro Superior” subregion. Two varieties (cv. Touriga Nacional and Touriga Franca) grown in five locations across the Côa Region were considered. Sugar accumulation in grapes, with concentrations between 170 and 230 g l-1, was used from 2014 to 2020 as an indicator of technological maturity conditioned by meteorological factors. The climatic time series were retrieved from the EU Copernicus Service, while sugar data were collected by a non-profit organization, ADVID, and by Sogrape, a leading wine company. The software for calibrating and validating this model framework was the Phenology Modeling Platform (PMP), version 5.5, using Sigmoid and growing degree-day (GDD) models for predictions. The performance was assessed through two metrics: Roots Mean Square Error (RMSE) and efficiency coefficient (EFF), while validation was undertaken using leave-one-out cross-validation. Our findings demonstrate that sugar content is mainly dependent on temperature and air humidity. The models achieved a performance of 0.65