 IVES 9 IVES Conference Series 9 Macrowine 9 Macrowine 2021 9 Grapevine diversity and viticultural practices for sustainable grape growing 9 Foliar application of specific inactivated yeast to enhance the varietal aroma precursors accumulation on cv. Traminer

Foliar application of specific inactivated yeast to enhance the varietal aroma precursors accumulation on cv. Traminer

Abstract

AIM: The production of grapes with a balanced composition is one of the main goals that agronomists and oenologists pursue to produce premium quality wines. The gap between technological (sugar/acid ratio) and aromatic maturity is expanding due to the increasing temperature and lack of rainfall during the ripening phase. In three consecutive years 2017, 2018 and 2019 we have evaluated the elicitor effect of the foliar application of a specific inactivated yeasts (LalVigne Aroma, Lallemand Inc) on the vine’s secondary metabolism with a specific effect on the aroma precursors accumulation.

METHODS: The experiment took place in Trentino Alto Adige (Italy) in a commercial vineyard of Vitis vinifera L. cv. Traminer. The application of the specific inactivated yeasts was performed according to the producers guidelines, two foliar treatments at 3 kg/ha each, the first at the beginning of veraison and the second ten days later. At harvest specific measurements were taken to assess the effect on grape quality and on organoleptic characteristic of the subsequent wines: yield, biochemical parameter, the free and glycosylated aromatic precursors in grapes with GC/MS.

RESULTS: In the three studied vintages there was not effect of the treatment on yield and biochemical parameter (sugar, pH, titratable acidity), while there was a significant impact on the aroma precursors. In both forms (free and glycosylated) the total amount of aroma precursors was higher in the treated grapes, in particular nerol, β-citronellol, geraniol, geranic acid and benzyl alcohol showed a significant increase. Thiols precursors of 3MH were significantly higher in treated plants. Organoleptic evaluation of the wines confirmed chemicals result.

CONCLUSIONS:

The results confirmed that the foliar application of the specific inactivated yeast tested in our trials positively impacted on grape and wine aroma profile without affecting the sugar accumulation and acidity degradation. This application is an efficient agronomic tool able to modify the secondary metabolism of the vines related to aroma precursors, increasing the varietal expression, without affecting sugars, acids and pH.

DOI:

Publication date: September 1, 2021

Issue: Macrowine 2021

Type: Article

Authors

Duilio Porro , San Michele , Fabrizio, BATTISTA.

Fondazione Edmund Mach Via Mach 1 38098 San Michele all’Adige (TN) – Italy, Fabrizio, BATTISTA. Lallemand Inc, Via Rossini 14/B, 37060 Castel D’Azzano (VR) Italy

Contact the author

Keywords

elicitor, inactivated yeast, thiols, traminer, aroma precursors, terpenes, climate change

Citation

Do high temperature extremes impact berry tannin composition?

Flavonoids, including flavonols, anthocyanins, and tannins, are important contributors to grape and wine quality, and their biosynthesis is strongly influenced by bunch microclimate.

Which heat test really represents the haze risk of a white Sauvignon wine ?

AIM: Different heat tests are used to predict a white wine haze risk after bottling. The most used tests are 30-60 min. at 80°C. Nevertheless, there is a lack of information about the relationship between the wine haze observed after such tests and the turbidities observed in the bottles after the storage/transport of the wines in more realistic Summer conditions (35-46°C during 3-12 days)

Zeowine: the synergy of zeolite and compost. Effects on vine physiology and grape quality

The trial aims to improve the protection and management of the soil, the well-being of the plant and the quality of production in the wine supply chain organic and biodynamic, using an innovative product “ZEOWINE” resulting from the composting of waste of the wine and zeolite supply chain.

Petiole phosphorus concentration is controlled by the rootstock genetic background in grapevine: is this a key for understanding rootstock conferred vigour?

Grapevine, Vitis vinifera, requires grafting on Phylloxera tolerant rootstocks of American origin in most viticultural areas of the world. The most commonly used species in rootstock creation are V. berlandieri, V. riparia and V. rupestris. Rootstocks not only provide tolerance to Phylloxera but assure the supply of water and mineral nutrients to the scion. The objective of this work was to determine to what extent rootstocks of different parentages alter the mineral composition of petioles of grapevine.

Updating the Winkler index: An analysis of Cabernet sauvignon in Napa Valley’s varied and changing climate

This study aims to create an updated, agile viticultural climate index (similar to the Winkler Index) by performing in-depth analyses of current and historical data from industry partners in several major winegrowing regions. The Winkler Index was developed in the early twentieth century based on analysis of various grape-growing regions in California. The index uses heat accumulation (i.e. Growing Degree Days) throughout the growing season to determine which grape varieties are best suited to each region. As viticultural regions are increasingly subject to the complexity and uncertainty of a changing climate, a more rigorous, agile model is needed to aid grape growers in determining which cultivars to plant where. For the first phase of this study, 21 industry partners throughout Napa Valley shared historical phenology, harvest, viticultural practice, and weather data related to their Cabernet sauvignon vineyard blocks. To complement this data, berry samples were collected throughout the 2021 growing season from 50 vineyard blocks located throughout 16 American Viticultural Areas that were then analyzed for basic berry chemistry and phenolics. These blocks have been mapped using a Geographic Information System (GIS), enabling analysis of altitude, vineyard row orientation, slope, and remotely sensed climate data. Sampling sites were also chosen based on their proximity to a weather station. By analyzing historical data from industry partners and data specifically collected for this study, it is possible to identify key parameters for further analysis. Initial results indicate extreme variability at a high spatial resolution not currently accounted for in modern viticultural climate indices and suggest that viticultural practices play a major role. Using the structure of data collection and analyses developed for the first phase, this project will soon be expanded to other wine regions globally, while continuing data collection in Napa Valley.