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. 

Download the PDF

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…

Nematode vectors, grape fanleaf virus (GFLV) incidence and free virus vine plants obtaining in “Condado de Huelva” vineyards zone

The « Condado de Huelva » Registered Appellation Origin Mark (RAOM) is located in the Province of Huelva, in the southwest of Andalucía (Spain), being limited by the Atlantic Ocean and the Province of Sevilla. « Zalema », a white high productive grapevine plant is its major cultivar. The predominant rootstocks used are « Rupestris du Lot », « Castel 196-17 », « Couderc 161-49 », Couderc 33-09 », « Richter 110 » and « Millardet 41-B ». Traditionally, « Zalema » cv. has been dedicated to the elaboration of amber, bouquet-flavoured wines and in the last years mainly to young, fruit-flavoured white table wines.

Read More

Impact of seaweeds extracts applied to grapevine cv Tempranillo

Grapevine is one of the most-frequently phytosanitary treated crop systems. Consequently, restrictions have been applied by the European Commission on the number of pesticide treatments and the maximum quantity of copper fungicides allowed per year. Moreover, there is a need and an increasing demand for more ecological-sustainable agricultural products.
Seaweeds are currently used as fertilizers in viticulture, as they have been proven to be beneficial in several ways related to growth and nutrition.

Read More

The impact of ethyl esters, monoterpenes and volatile thiols to the perception of tropical fruit aromas in white wines

Many varietal white wines have aroma qualities that incorporate various tropical fruit aromas. These tropical fruit aromas are found to be considered positive qualities of the wines with consumers having positive emotional responses [1].

Read More

Evaluation of two transmittance meters in estimating chlorophyll and nitrogen concentrations in grapevine cultivars

Two transmittance-based chlorophyll meters (SPAD-502 and CCM-200) were evaluated in estimating chlorophyll (Chl) and nitrogen (N) levels in grapevine leaves.

Read More

INFLUENCE OF CHITOSAN, ABSCISIC ACID AND BENZOTHIADIAZOLE TREATMENTS ON SAVVATIANO (VITIS VINIFERA L.) WINES VOLATILE COMPOSITION PROFILE

In the last decades the use of bioestimulants in viticulture have been promoted as alternative to conven- tional pesticides. Moreover, as bioestimulants promote the biosynthesis of secondary metabolites in grape berries, several studies had investigated their influence on the accumulation of phenolic com- pounds (Monteiro et al., 2022). However, few studies, so far, are focused on the accumulation of the vo- latile compounds and their impact on the produced wines (Giménez-Bañón et al., 2022; Gomez- Plaza et al., 2012; Ruiz Garcia et al., 2014).
This study was conducted in a single vineyard of white autochthonous grapevine variety Savvatia- no (Vitis vinifera L.) in Muses Valley (Askri, Viotia, Greece). Chitosan (CHT), Abscisic Acid (ABA) and Benzothiadiazole (BTH) were applied.

Read More