terclim by ICS banner
IVES 9 IVES Conference Series 9 Grapevine sugar concentration model in the Douro Superior, Portugal

Grapevine sugar concentration model in the Douro Superior, Portugal

Abstract

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<EFF<0.92, with an error of 2.90<RMSE< 5.87. Overall, the behaviour of the two cultivars was similar, whereas the atmospheric variables provided suitable modelling of technological maturity. The models provided herein may help growers to better define and plan their annual activities, thus being a key decision support tool in viticulture. 

DOI:

Publication date: May 31, 2022

Issue: Terclim 2022

Type: Poster

Authors

Nicolò Clemente1, João A. Santos1, Natacha Fontes2, António Graça2, Igor Gonçalves3 and Helder Fraga1

1Centre for the Research and Technology of Agro-Environmental and Biological Sciences, CITAB, Universidade de Trás-os-Montes e Alto Douro, UTAD, Vila Real, Portugal 
2Sogrape Vinhos S.A., Avintes, Portugal 
3Associação para o Desenvolvimento da Viticultura Duriense, Edifício Centro de Excelência da Vinha e do Vinho Parque de Ciência e Tecnologia de Vila Real, Régia Douro Park, Portugal 

Contact the author

Keywords

viticulture, yield, Douro, Portugal, climate change

Tags

IVES Conference Series | Terclim 2022

Citation

Related articles…

Phenolic composition and physicochemical analysis of wines made with the syrah grape under double pruning in the Brazilian high-altitude cerrado

Wine growing has proven to be a development opportunity for agribusiness in several new regions of brazil, including the federal district. There are more than ten existing wineries, established in the last five years. Through the double pruning system, which consists of trimming the growing shoots in the summer and positioning the ripening of the fruits in a cooler period of the season, the grapes are sought to ripen more completely. The syrah variety has shown excellent adaptation to this cycle management model.

Fast, and full microbiological wine analysis using triple cellular staining.

We propose here a brand new large routine microbiological analysis method intended for oenology, in flow cytometry, using high performance equipment and triple selective cell staining, activated by fluorescence. The results and practical applications of the method are presented: Brettanomyces (Dekkera) Monitoring, fermentations monitoring, bottling and enological practices monitoring.The method allow a complete new microbiological tool for wine industry.The method has been accredited ISO 17025 in our laboratories.

Aromatic profile of chardonnay – clone 809: from berry to sparkling wine in an altitude vineyard

ine consumption is linked to the aromatic profile, consumer acceptance, and reflects the viticultural and oenological practices applied, together with the study related to clones is a way to evaluate the adaptation

Monitoring of microbial biomass to characterise vineyard soils

Le sol est un facteur important permettant la croissance de la vigne. Les propriétés physiques et chimiques, mais aussi microbiologiques ont une influence sur beaucoup des fonctions du sol comme la structure, le drainage, la fertilité, déterminant la vigueur des plantes et le potentiel œnologique des raisins.

Grape berry size is a key factor in determining New Zealand Pinot noir wine composition

Making high quality but affordable Pinot noir (PN) wine is challenging in most terroirs and New Zealand’s (NZ) situation is no exception. To increase the probability of making highly typical PN wines producers choose to grow grapes in cool climates on lower fertility soils while adopting labour intensive practices. Stringent yield targets and higher input costs necessarily mean that PN wine cost is high, and profitability lower, in line-priced varietal wine ranges. To understand the reasons why higher yielding vines are perceived to produce wines of lower quality we have undertaken an extensive study of PN in NZ. Since 2018, we established a network of twelve trial sites in three NZ regions to find individual vines that produced acceptable commercial yields (above 2.5kg per vine) and wines of composition comparable to “Icon” labels. Approximately 20% of 660 grape lots (N = 135) were selected from within a narrow juice Total Soluble Solids (TSS) range and made into single vine wines under controlled conditions. Principal Component Analysis of the vine, berry, juice and wine parameters from three vintages found grape berry mass to be most effective clustering variable. As berry mass category decreased there was a systematic increase in the probability of higher berry red colour and total phenolics with a parallel increase in wine phenolics, changed aroma fraction and decreased juice amino acids. The influence of berry size on wine composition would appear stronger than the individual effects of vintage, region, vineyard or vine yield. Our observations support the hypothesis that it is possible to produce PN wines that fall within an “Icon” benchmark composition range at yields above 2.5kg per vine provided that the Leaf Area:Fruit Weight ratio is above 12cm2 per g, mean berry mass is below 1.2g and juice TSS is above 22°Brix.