terclim by ICS banner
IVES 9 IVES Conference Series 9 GiESCO 9 Precipitation variability in a temperate coastal region and how it affects Tannat and Albariño cultivars 

Precipitation variability in a temperate coastal region and how it affects Tannat and Albariño cultivars 

Abstract

Context and purpose of the study – Climate is one of the main components that defines the development and behavior of the plant, conditioning the health status and the final quality of the grapes. In temperate coastal climates such as in Uruguay (latitude 35° S, longitude 55° O), precipitations during the growing season present high interannual variability, with a average of 100 mm per month. This variability means that plants must adapt to conditions from one year to the next. The objective of this work was to evaluate the performance of two cultivars; Tannat, adapted cultivar of Uruguay and Albariño, a cultivar recently introduced in the country, in relation with precipitations during three growing seasons. 

Material and methods – We analyzed precipitation data from two agro-meteorological stations in southern Uruguay over 31 year (1992-2022). We calcuted descriptive indexes of precipitation (PP) during the growing season (September to march) and dry periods (moving average of 15 days with PP less than 6 mm).  We established  trends of precipitations using means of first-order linear regressions. We measured water potential at different phenological stages (25, 33, 34 and 37 of Eichhorn-Lorenz scale) of Tannat and Albariño, over three contrasting growing seasons in terms of precipitation (2019: preveraison precipitation; 2020: dry and 2021: postveraison precipitation) in order to asses plant water status, as well as plant physiological parameters (leaf area, yield, cluster weight, pruning weight, ravaz index and leaf/yield balance index), grapes final composition and  health status at harvest.

Results – In the last 31 yeear, precipitations during the growing season ranged from 405 to 1154 mm and 64 to 599 mm during the grape ripening period. In 197 days of the growing cycle in Uruguay (1 Sep – 15 Mar), an average of 66 days had precipitation, which means one event every three days. However, when analyzing the dry periods, an average of 18 events per growing season were recorded with a variability from 0 to 50 periods, which shows the alternation between excess and deficit of water in the terroir. The 31-year trend showed an increase in these dry events (r2 0.32; p-value = 0.07) and a decrease in days with precipitation (r2 = -0.31, p-value = 0.07). When anayzing the cutlivar response to the 2019, 2020 and 2021 cycles, both cultivars showed significant differences in soluble solids, pH and berry weight. Albariño showed differences in bunch weight, while Tannat showed differences in total acidity, anthocyanins, leaf area, yield with incidence of Botrytis cinerea sp., pruning weight and bunch index. Therefore, the high inter-annualvariability had an impact on Tannat performance. Still, Albariño was more stable between rainy and dry years, an interesting option for winegrowers searching for durable and sustainable products.

DOI:

Publication date: July 7, 2023

Issue: GiESCO 2023

Type: Poster

Authors

Ramiro TACHINI1, Mercedes FOURMENT1, Milka FERER1

1Faculty of Agronomy, Universidad de la República Oriental del Uruguay. Av. Garzón 780, CP 12900 Montevideo, Uruguay

Contact the author*

Keywords

Albariño, Tannat, climate variability, precipitation, Uruguay

Tags

GiESCO | GIESCO 2023 | IVES Conference Series

Citation

Related articles…

An excessive leaf-fruit ratio reduces the yeast assimilable nitrogen in the must

Yeast assimilable nitrogen (YAN) in the grape must is a key variable for wine quality as a source of aroma precursors. In a situation of YAN deficiency, a foliar urea application upon the vine at veraison enhances YAN concentration and facilitates must fermentation. In 2013, Agroscope investigated the impact of leaf-fruit ratio on the nitrogen (N) assimilation and partitioning in grapevine Vitis vinifera cv. Chasselas following foliar-urea application with the aim of improving its efficiency on the YAN concentration.

Extraction of polyphenols from grape marc by supercritical fluid extraction (SFE) and evaluation of their ‘bioavailability’ as dietary supplements

In the winemaking process, several compounds that remain in the grape skins and seeds after the fermentation stage are bioactive-compounds (substances with potential beneficial effects on health) that can be extracted in order to recovery valuable substances with a high commercial value for the cosmetic, food (nutraceuticals) and pharmaceutical industries. The skins contain significant amounts of bioactive substances such as tannins (16-27%) and other polyphenolic compounds (2-6.5%) in particular, catechins, anthocyanins, proanthocyanins, quercetin , ellagic acid and resveratrol.

The impacts of frozen material-other-than-grapes (MOG) on aroma compounds of red wine varieties

An undesirable note called “floral taint” has been observed in red wines by winemakers in the Niagara region caused by large volumes of frozen leaves and petioles [materials-other-than-grapes (MOG)] introduced during mechanical harvest and subsequent winemaking late in the season. The volatiles, which we hypothesized are responsible, are primarily terpenes, norisoprenoids, and specific esters in frozen leaves and petioles. The purpose of this study was to investigate the volatile compounds which may cause the floral taint problem and explore how much of them (thresholds) may lead to the problem. Also, the glycosidic precursors of some of these compounds were analyzed to see the changes happening during frost events.

Aromatic profile of six different clones of Chardonnay grape berries in Minas Gerais (Brazil)

Aromas are one of the key points in food analysis since they are related to character, quality and consequently consumer acceptance. It is not different in the winery industry, where the aromatic profile is a combination of viticultural and oenological practices. Based on the development of more aromatic clones and on the potential to produce sparkling wines at Caldas, in the southern region of Minas Gerais (Brazil) (21°55´S and 46°23´W, altitude 1,100m), the aim of this work was the determination of volatile compounds in six different clones of Chardonnay grape berries to better understand which compounds add bouquet to the wine, and additionally comprehend the impacts of the edaphoclimatic and annual conditions on the improvement of grape-growing and winemaking practices.

Improving stilbenes in vitis Labrusca L. Grapes through methyl jasmonate applications

Grapes (Vitis sp.) are considered a major source of phenolic compounds such as flavonols, anthocyanins and stilbenes. Studies related to the beneficial effects of these compounds on health have encouraged research aimed at increasing their concentration in fruits. On this behalf, several plant growth regulators such as jasmonic acid and its volatile ester, methyl-jasmonate (MeJa), have demonstrated promising results in many fruits. However, Brazilian subtropical climate might interfere on treatment response. The present study aims to evaluate the application of MeJa in the pre-harvest period in Concord and Isabel Precoce grapes (Vitis labrusca L.).