GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 Impact of deficit irrigation strategies on terpene concentration in Gewürztraminer grapes

Impact of deficit irrigation strategies on terpene concentration in Gewürztraminer grapes

Abstract

Context and purpose of the study – Deficit irrigation is a viticultural practice often applied to improve the phenolic composition of red grapes and wines. However, the impact of this practice on grape terpenes – key aromatics for several grapes and wines – remains largely unknown. This study investigated the impact of deficit irrigation strategies on free and glycosylated terpenes in Gewürztraminer grapes.

Material and methods – In a field study conducted in Oliver, BC, in 2016, 2017, and 2018, deficit irrigation regimes were applied to Gewürztraminer vines at different developmental stages (pre-veraison = Early Deficit, ED; post-veraison = Late Deficit, LD; throughout the season = Prolonged Deficit, PD). A well-irrigated control (CN) treatment was also established. Treatments were replicated four times accordingly to a randomized block design. The impact of deficit irrigation treatments on vine physiology and berry metabolism was characterized with eco-physiological, biochemical, and molecular analyses. Starting three weeks after fruit set, midday-leaf water potential was measured every 7-14 days and leaf gas exchanges every 14-21 days. Berry samplings were conducted every 7-14 days to assess the effect of deficit irrigation treatments on berry sugar (total soluble solid, TSS), acid (titratable acidity, TA), and terpene concentration, as well as the expression of terpene genes. Free and glycosylated terpenes were identified and quantified using a SPME-GC-MS and a LI-GC-MS, respectively. Gene expression was analyzed using a quantitative RT-PCR.

Results – Midday leaf water potential, photosynthesis, and transpiration rates were reduced by deficit irrigation. ED, LD, and PD reduced vine yield when compared to CN, but LD reduction was small and not consistent among years. Sugar levels were also reduced by deficit irrigation, particularly by LD and PD. Total free terpenes were marginally affected by deficit irrigation treatments (P = 0.065); however, the concentration of specific terpenes, such as geraniol, was significantly (P< 0.05) higher in LD than in CN berries. LD did not increase the expression of terpene genes (e.g., VviDXSs, VviHDR, VviTPSs), suggesting that the observed increase in the concentration of some free terpenes was not regulated at the transcriptional level. Total glycosylated terpenes at harvest did not change among treatments.

DOI:

Publication date: March 12, 2024

Issue: GiESCO 2019

Type: Poster

Authors

Yevgen KOVALENKO1, Ricco TINDJAU1, Simone Diego CASTELLARIN1

1 Wine Research Centre, The University of British Columbia, 2205 East Mall, Vancouver, BC, V6T0C1, Canada

Contact the author

Keywords

Aroma, Grapevine, Ripening, Water Deficit, Yield

Tags

GiESCO | GiESCO 2019 | IVES Conference Series

Citation

Related articles…

Soil clay mineralogy and potassium buffer capacity as potential wine quality determining factors in Western Cape vineyards

The potassium (K) supply characteristics and clay mineralogies of a population of Western Cape soils were investigated to determine their potential effects on vine K uptake and wine quality. The total K contents of granite-, shale- and sandstone-derived soils varied, averaging 33.7, 26.1 and 4.5 cmol(+)/kg, respectively. Corresponding M NH4Cl exchangeable soil K levels were: 0.172, 0.042 and 0.035 cmol/kg.

Study of the volatile aroma profile of five Italian grape varieties submitted to controlled postharvest withering

Wines made with grapes submitted to postharvest dehydration are often referred to as “passito” or “straw wines.” This distinct style of winemaking consists of a process of water loss that allows the berries to undergo a mild water stress and senescence process [1].

USING CHECK-ALL-THAT-APPLY (CATA) TO CATEGORIZE WINES: A DECISION-MAKING TOOL FOR WINE SELECTION

Bordeaux is the largest appellation vineyard in France. This contrasting vineyard with varied terroirs offers all styles of wine, resulting from the blending of several grape varieties. If these different profiles make the renown of Bordeaux wines, it can appear as a constraint when the aim is to study Bordeaux wines in their diversity. The selection of a representative sample can be performed by a sensory analysis carried out by trained panelists or by wine professionals, which can take several forms: consensus among experts, conventional descriptive analysis, typicality or quality evaluation. However, because of time, economic, and logistical constraints, these methods have limited applications. As an alternative to classical descriptive analysis, more intuitive methods that do not require training have been proposed recently to describe wines using an expert panel such as Napping, Free Choice or Flash Profiling, CATA or RATA.

Valpolicella chemical pattern of aroma ‘terroir’ evolution during aging

Valpolicella is an Italian region famous for the production of high quality red wines. Wines produced in its different sub-regions are believed to be aromatically different, as confirmed by recent studies in our laboratory. Aging is a very common practice in Valpolicella and it is required by the appellation regulation for periods up to four years. The aim of this study was to investigate the evolution, during aging, of volatile chemical composition of Valpolicella wines obtained from grapes harvested in different sub-regions during different vintages.

Vino e paesaggio: materiali per il governo del territorio vitivinicolo. Il piano regolatore delle città del vino

S’intende per Piano Regolatore delle Città del Vino la metodologia per redigere la parte strutturale dello strumento comunale di governo del territorio. Parliamo, infatti, del principale strumento comunale di governo del territorio, così come è venuto maturando nella riflessione delle Città del Vino, strumento che si misura con la sfida di governare tutto il territorio in modo coerente e sostenibile, a partire dal riconoscimento del valore del “sistema vigneto” e della sua intrinseca fragilità.