terclim by ICS banner
IVES 9 IVES Conference Series 9 Optimizing disease management in the Rioja wine region: a study on Erisiphe necator and the Gubler-Thomas model

Optimizing disease management in the Rioja wine region: a study on Erisiphe necator and the Gubler-Thomas model

Abstract

Erisiphe necator is endemic in the Rioja Appellation of Origin. Vine growers exert significant effort to protect their crops, given the economic losses this disease causes. Different studies have shown that using Gubler-Thomas Model (GTM) can reduce treatments by up to 20% compared to a full-time protection strategy. This reduction is achieved by optimizing applications based on temperature variations in late spring and summer when the disease’s conidial stage is active. Additionally, since GTM is quite conservative further reductions in sprayings seem feasible.
To evaluate GTM and disease severity, 11 experimental plots with three treatments: a) Unsprayed Control (UC), b) Fully Protected crop – periodic sprayings according to product prescriptions (FP), and c) sprayings following Gubler-Thomas (GT) were established in different areas of La Rioja wine region from 2018 to 2023. Results revealed significant variability in disease severity, with some years experiencing minimal damage in bunches across all treatments, including UC. GTM did not detect these variations in disease severity, indicating a similar risk level between years. Despite this, following GTM advice instead of FP practice lead to a 20% reduction in treatments, with no effect on disease symptoms on the bunches.
This raises questions about the seasonal variation. Are spring conditions causing higher severity during the conidial stage? Is there a specific climatic parameter or measurement distinguishing a severe season from a mild one? Factors like radiation, precipitation, or extreme temperatures in different months might contribute to this variability.

DOI:

Publication date: June 13, 2024

Issue: Open GPB 2024

Type: Poster

Authors

Joaquín Huete1*, Vanessa Tobar1, Beatriz López2, Alicia Pou3

1 Servicio de Producción Agraria. DG. Agricultura y Ganadería. Gobierno de La Rioja
2 Consejería. Educación, Cultura y Turismo. Gobierno de La Rioja
3 Instituto de Ciencias de la Vid y el Vino (ICVV). CSIC

Contact the author*

Keywords

powdery mildew, bioclimatic models, Gubler-Thomas

Tags

IVES Conference Series | Open GPB | Open GPB 2024

Citation

Related articles…

Politics meets terroir. The story of Prosecco – Are GI’s just a protectionist racket?

The recent Free Trade Agreement negotiations between Australia and the European Union have again put the issue of Geographical Indications (GIs) in the spotlight. Australia has long demonstrated its understanding of GIs and maintains a clear and rigorous GI protection system for wine. For many years, Australia’s wine sector was a strong advocate for GIs and a strong system to protect the

VOLTAMETRIC PROFILING OF RED WINE COMPOSITION DURING MACERATION: A STUDY ON FOUR GRAPE VARIETIES

During red wine vinification, maceration allows the must, and consequently the wine, to be enriched with several compounds that contribute to the creation of the typical organoleptic characteristics of red wines. Among these, extraction of polyphenols (PPs) during maceration is a major process of enological interest.
The purpose of this study was the evaluate the suitability of a rapid analytical approach based in linear sweep voltammetry to monitor PPs extraction during vinification.

Study of the aromatic oxidation markers of Tempranillo long aged wines

The aromatic quality of wines after a long aging period in bottle is one of key points for oenologists. The objective of this work is to determine the main representative aromatic compounds found in long aged wines from D.O.Ca. Rioja. This study was made by 32 wines from 1971 to 2010 vintages. Sotolon, acetaldehyde, phenylacetaldehyde, 1,1,6-trimethyl-1,2-dihydronaptalene (TDN), β-damascenone, Y-decalactone and Y-dodecalactone were determined as the most important oxidation markers by GC-MS analysis. Moreover, sensory analysis using triangular tests were performed from wines with and without the addition of the mentioned compounds. Four different concentrations of each odorant were added, as individual compounds and as mixtures. The additions were ranged from values close to the reference odour thresholds up to high level concentrations. The most identified aroma was sotolon, which is commonly associated to curry and coffee liqueur aromatic notes. Other oxidative compounds were easily detected by panellists, such as Y-decalactone (peach compote), Y-dodecalactone (ripe fruit). The mixtures of the odorants were most easily detected than the individual compounds. It should be noted that acetaldehyde and phenylacetaldehyde were rarely perceived and distinguished.

What is the best time to harvest grapes destined for withering? Ripeness and dehydration length affect phenolic composition of Nebbiolo grapes

Sfursat di Valtellina is a DOCG reinforced wine produced in Valtellina from partially withered red grapes of Vitis vinifera L. cv. Nebbiolo. The grape ripeness degree and the dehydration process strongly influence the physicochemical characteristics of grapes [1, 2, 3]. In particular, grape skin and seeds contain several classes of phenolic compounds strictly associated with red wine quality, which are significantly affected by these factors [4]. The aim of this research is to assess the combined influence of different ripeness levels and withering rates on the standard chemical composition and phenolic profile of winegrape in order to provide new insights and approaches to the management of withering, searching for the valorization of grape potentialities.

Understanding the impact of climate change on anthocyanin concentrations in Napa Valley Cabernet Sauvignon

Climate change is having a significant impact on the wine industry through more regular drought conditions, fires, and heat events, leading to crop loss. Furthermore, these events can reduce overall quality of the fruit, even when crop yields are not impacted. Anthocyanins are considered one of the most important classes of compounds for red wine production and are known to be sensitive to vine water status and heat events.