GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 GiESCO 2019 9 Climate change 9 Harvest dates – temperature relationships and thermal requirements of winegrape varieties in Greece: observed and future climate responses

Harvest dates – temperature relationships and thermal requirements of winegrape varieties in Greece: observed and future climate responses

Abstract

Context and purpose of the study Air temperature is arguably one of the most decisive factors for winegrape varieties developmental cycle, ripening potential and yield. Taking into account that predicted future warmer conditions will possibly impose challenges in global viticulture, it is of outmost importance to understand the adaptive capacity of each variety in the current and future climate conditions. Thus, the objective of this study was twofold: (a)to investigate the relationships between air temperature during the ripening period and harvest dates for eight principally cultivated indigenous winegrape varieties (one for each winegrape region of Greece) and (b) to assess varieties’ thermal demands (four varieties) using the standard growing degree day (GDD) formula and project harvest date in two future windows using a multi-Regional Climate Model ensemble dataset.

Material and methods Harvest dates were assembled from four white [cvs. Muscat of Alexandria (Limnos), Assyrtiko (Santorini), Muscat blanc (Samos) and Athiri (Rodos)] and four red [cvs. Moschofilero (Tripoli), Mavrodaphni (Pyrgos), Mandilaria (Crete) and Xinomavro (Naoussa)] varieties, covering a period from 11 to 44 years. Daily observations of maximum (TX) and minimum (TN) air temperature were obtained from the Hellenic National Meteorological Service (HNMS) in order: (a) to investigate the relationships between harvest dates and temperature conditions during the ripening period and (b) to o calculate growing degree days (GDD, C units) for each variety. In addition, high resolution ensemble datasets (derived from 5 model experiments) with the two representative concentration pathways 4.5 (RCP4.5) and 8.5 (RCP8.5) were employed to project harvest dates for two future time windows [future projection 1 (FP1): 2041-2065 and future projection 2 (FP2): 2071-2095]. Pearson’s correlation coefficient was used to investigate relationships between air temperature and harvest date. Statistical significance was set at p< 0.05.

Results Harvest dates showed negative trends in six out of eight cases (four cases statistically significant) while in two areas (Crete and Pyrgos) harvest occurs later. In addition, harvest date – temperature analysis showed significant negative relations in seven out of eight cases. Rodos (cv. Athiri) was the only case with a significant positive relationship. Heat requirement analysis revealed that two varieties (cvs. Muscat of Alexandria and Moschofilero) needed almost 1700 GDD to achieve full maturity while the other two varieties (cvc. Mavrodaphni and Xinomavro) exceeded 2000 GDD units (2021 and 2049, respectively). Future projection analysis showed that harvest will shift earlier for all varieties (ranging approximately from one to two months) and this shift in both time windows will depend on the variety and the selected emission scenario. 

DOI:

Publication date: June 19, 2020

Issue: GiESCO 2019

Type: Article

Authors

Georgios C.KOUFOS (1), Theodoros MAVROMMATIS (1), Stefanos KOUNDOURAS (2), Gregory V. JONES (3)

(1) Department of Meteorology and Climatology, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
(2) Laboratory of Viticulture, School of Agriculture, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
(3) Center for Wine Education, Linfield College, McMinnville, Oregon, USA.

Contact the author

Keywords

 Grape variety, Heat requirements, Climate change, Regional climate models

Tags

GiESCO 2019 | IVES Conference Series

Citation

Related articles…

Relationship between soil and grapevine variety in the wineyard of Jura: example for the “Trousseau” variety from the “Terroir” of Montigny-Lès-Arsures (France)

Seven plots located in the commune of Montigny-lès-Arsures (Jura, 39), planted with grapevine varieties Trousseau and Savagnin, were chosen for a study of soil pits and a distribution of major and trace chemical elements in soils and wines. It was shown that the mineral matrix of the soil reflects the geological substratum and the sub-surface alteration process, while the organic soil matrix depends on agro-viticultural practices.

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.

High-resolution aerial thermography for water stress estimation in grapevines

Aerial thermography has emerged as a promising tool for water stress detection in grapevines, but there are still challenges associated with this technology, particularly concerning the methodology employed to extract reliable canopy temperature values. This consideration is relevant especially in vertically trained vineyards, due to the presence of multiple surfaces which are captured by drone thermal cameras with high-resolution. To test the technology and the data analysis required, a field study was conducted during the 2022-2023 season in a model vineyard with multiple scions-rootstock combinations trained on a vertical shoot-positioning (VSP) system. Additionally, three irrigation regimes were implemented to introduce variability in water stress levels.

The influence of soil management practices on functional traits and biodiversity of weed communities in Swiss vineyards

Green cover in vine rows provides many ecological services, but can also negatively impact the crop, depending on the weed species. The composition of a vineyard weed community is influenced by many parameters. Ensuring an evolution of the vine row flora into a desired direction is therefore very complex. A key step towards this goal is to know which factors influence the establishment of the weed community and which types of communities are best suited for vineyards. In this study, we analysed the weed communities of several vineyards in the Lake Geneva region (379 botanical surveys on 117 plots), with the aim to highlight the links between soil management practices (chemical and mechanical weeding, mowing, mulching roll) and phytosociological profiles, biodiversity and selected functional traits (growth forms, life strategies, root depth). T

Viticultural zoning in the province of San Juan, Argentina. Preliminary results, year 2000

La région viticole de San Juan (Argentine) est marquée par des températures très élevées et des variations diurnes faibles. La valorisation de la connaissance de cet environnement et de ses interactions avec le fonctionnement de la vigne et le lien au vin passent par l’étude de ses terroirs et de leur caractérisation. Le point de départ de ce travail est l’étude des zones mésoclimatiques aptes à la culture de la vigne de la Province de San Juan et à la caractérisation des sols de cette même région. L’objectif est de définir le potentiel vitivinicole des zones considérées.