Terroir 2012 banner
IVES 9 IVES Conference Series 9 International Terroir Conferences 9 Terroir 2012 9 Grapegrowing climates 9 Impact of microclimate on berry quality parameters of white Riesling (Vitis vinifera L.)

Impact of microclimate on berry quality parameters of white Riesling (Vitis vinifera L.)

Abstract

Knowledge has been accumulated on the impact of microclimate, in particular berry temperature and irradiation, for a wide range of red varieties. However, little research has been dedicated on the effects of the same factors on the quality of white grape varieties.

In this study we present results of the effects of microclimate on the composition of white Riesling (Vitis vinifera L.) under different row orientations. The microclimatic parameters monitored in this study were canopy humidity and temperature, berry surface temperature using infrared thermography, ambient humidity, temperature, wind speed and irradiation parameters. Bunches of different exposure within the canopy of three different row orientations (North to South; East to West; South-West to North-East) were monitored. In addition to the natural environment, some bunches were sheltered in boxes to exclude any impact of light. Further, a defoliation treatment was established to provide maximum light interception.

Results of the study showed that bunches under higher radiation interception, had a faster malic acid degradation and berries were accumulating more flavonols, while the differences in sugar accumulation seemed to depend on leaf peak temperatures rather than on the exposure of the berries.

DOI:

Publication date: August 28, 2020

Issue: Terroir 2012

Type: Article

Authors

Matthias FRIEDEL (1), Michael WEBER (1), Jeanette ZACHARIAS (2), Claus-Dieter PATZ (2), Manfred STOLL (1)

(1) Geisenheim Research Center, Department of Viticulture, Von-Lade-Str. 1, 65366 Geisenheim, Germany
(2) Geisenheim Research Center, Department of Wine Chemistry and Beverage Technology Von-Lade-Str. 1, 65366 Geisenheim, Germany

Contact the author

Keywords

Row Orientation, Riesling, Microclimate, Berry Temperature, Flavonoids

Tags

IVES Conference Series | Terroir 2012

Citation

Related articles…

Zoning like base instrument for the agronomist’s work in vineyard

Ad una prima analisi l’interesse dimostrato dal settore produttivo nei confronti della zonazione vitivinicola è da ricondursi al fatto che dopo i primi approcci puramente accademici

Assessing the relationship between cordon strangulation, dieback, and fungal trunk disease symptom expression

Grapevine trunk diseases including Eutypa dieback are a major factor in the decline of vineyards and may lead to loss of productivity, reduced income, and premature reworking or replanting. Several studies have yielded results indicating that vines may be more likely to express symptoms of vascular disease if their health is already compromised by stress. In Australia and many other wine-growing regions it is a common practice for canes to be wrapped tightly around the cordon wire during the establishment of permanent cordon arms. It is likely that this practice may have a negative effect on health and longevity, as older cordons that have been trained in this manner often display signs of decay and dieback, with the wire often visibly embedded within the wood of the cordon. It is possible that adopting a training method which avoids constriction of the vasculature of the cordon may help to limit the onset of vascular disease symptom expression. A survey was conducted during the spring of two consecutive growing seasons on vineyards in South Australia displaying symptoms of Eutypa lata infection when symptomless shoots were 50–100 cm long. Vines were assessed as follows: (i) the proportion of cordon exhibiting dieback was rated using a 0–100% scale; (ii) the proportion of canopy exhibiting foliar symptoms of Eutypa dieback was rated using a 0–100% scale; (iii) the severity of strangulation was rated using a 0–4 point scale. Images were also taken of each vine for the purpose of measuring plant area index (PAI) using the VitiCanopy App. The goal of the survey was to determine if and to what extent any correlation exists between severity of strangulation and cordon dieback, in addition to Eutypa dieback foliar symptom expression.

Foliar application of urea improved the nitrogen composition of Chenin grapes

The nitrogen composition of the grapes directly affects the developments of alcoholic fermentation and influences the final aromatic composition of the wines. The aim of this study was to determine the effect and efficiency of foliar applications of urea on the nitrogen composition of grapes. This study was carried out during 2023 vintage and in the Chenin vineyard located in Estacion Experimental Mendoza (Argentina). Three urea concentrations 3, 6 and 9 Kg N/ha (C1, C2, and C3, respectively) and control (T) were applied in this vineyard at veraison. In all solutions were added 1ml/l of Tween 80 ® surfactant.

Do natural wines differ from conventionally-produced wines?

In recent years, consumer awareness for consuming healthy and environmental sustainability products has considerably increased [1]. In an ever-changing and highly competitive environment such as the wine sector, production of wines without sulfites, or biodynamic, organic or vegan wines, has experienced an important increase to meet the new needs of consumers [2,3]. Beyond these categories of regulated products, a new concept has emerged: natural wines (NW), for which there is not an established definition or legal regulation. Rather, producers have a personal idea of naturalness under the premise of applying minimal intervention from grape to wine production [4]. In this context, it is hypothesized that self-defined natural wines are different from conventional wines (CW) in their sensory and chemical profile. The predicament of natural wine is based on anecdotic declarations and assumes that minimal intervention guarantees the production of wines with organoleptic properties able to express the “terroir” and thus promote wine diversity, plurality and sensory typicity against the risk of standardization of CW.

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.