Macrowine 2021
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

Related articles…

Spatial determination of areas in the Western Balkans region favorable for organic production

In problematic conditions for production of grapes and wine caused by the COVID-19 pandemic and the resulting occurrence of wine surpluses, producers are increasingly turning to the innovative viticulture and winemaking of products that are more appealing to the market and the consumers. On the other hand, consumption of the food safety or organic products, and therefore of organic grapes and wine, is increasingly common in the world, in particular in Europe. The Regional Rural Development Standing Working Group (SWG RRD), as a regional intergovernmental organization gathers actors in the viticulture and winemaking sector from states and territories of the Western Balkans (South-East Europe) in the Expert Working Group for Wine, with the aim of improving viticulture and winemaking in this region through joint activities. In accordance with the aforementioned, the SWG RRD is working on advancing organic production of grapes and wine, and on recognition of specificities of the terroir of wine-growing areas in Western Balkans. In addition, as part of the project “Facilitation of Exchange and Advice on Wine Regulations in Western Balkan Countries” helmed by the German Federal Ministry of Food and Agriculture, in addition to harmonization of relevant legislation with EU regulations, efforts are being invested towards recognition of organic wines. Within activities and project implemented by this organization, expert analyses and scientific research of the terroir of Western Balkans were carried out, and some of the results are presented in this paper.

Effects of graft quality on growth and grapevine-water relations

Climate change is challenging viticulture worldwide compromising its sustainability due to warmer temperatures and the increased frequency of extreme events. Grafting Vitis vinifera L.

Combining effect of leaf removal and natural shading on grape ripening under two irrigation strategies in Manto negro (Vitis vinifera L.)

The increasingly frequent heat waves during grape ripening pose challenges for high quality wine grape production. Defoliation is a common practice that can improve the control of diseases in bunches, but also it increases the exposure to sunlight. Grapes exposed to solar radiation reach temperatures over the optimum for berry development and maturation. This makes the development of irrigation and canopy management techniques of great importance to maximize yield and grape quality. A field experiment was carried out during 2021 using Manto negro wine grapes to study the effect of applied irrigation and different light exposure levels on grape quality. Two irrigation treatments were imposed based on the frequency and amount of water doses in a four-block experimental vineyard at Bodega Ribas (Mallorca). Three light exposure treatments were randomly applied in each irrigation plot. The light treatments included exposed clusters from pea size, non-exposed clusters, and shaded clusters after softening. Leaf area index and canopy porosity was estimated every 2 weeks. Midday leaf water potential was measured weekly. Additionally, apparent electrical conductivity was measured between rows to estimate the soil water content variability. Light and temperature sensors were installed at the bunch level to quantify the differences in bunch temperature and light intensity among treatments. The effect of irrigation and cluster light exposure on berry weight, TSS, TA, malic acid, tartaric acid, K+, and pH were analysed at 5 moments along grape ripening. During different heat waves, the natural shading technique decreased the maximum bunch temperature around 10 °C respect to the exposed bunches in both irrigation strategies. The combination of defoliation and shading techniques after softening decreased TSS at harvest and affected most of the quality parameters during the last stages of ripening, showing an interesting technique to delay ripening in warm viticulture areas.

Influence of weather and climatic conditions on the viticultural production in Croatia

The research includes an analysis of the impact of weather conditions on phenological development of the vine and grape quality, through monitoring of four experimental cultivars (Chardonnay, Graševina, Merlot and Plavac mali) over two production years. In each experimental vineyard, which were evenly distributed throughout the regions of Slavonia and The Croatian Danube, Croatian Uplands,

Towards adaptation to climate change in Rioja: Quality evaluation of wines obtained from Grenache x Tempranillo selections

The wine sector is of great relevance and tradition in Mediterranean countries, however, it may be most susceptible to climate change. In recent years, wine production is facing changes worldwide, both at environmental as well as commercial levels, due to global warming and the shift in consumers’ preferences. Wine growers and wine makers are in search of solutions that allow to face these new challenges. One of the most promising initiatives in the long term is the introduction of new plant materials, specifically intraspecific hybridizations between premium varieties that may improve traditional germplasm in its adaptation to climate change. These inter-varietal crosses have the potential to generate quality wines, whilst maintaining the regional typicity, and constitute an attractive alternative for the consumer due to their sensory attributes. In this study, we have evaluated wines from 29 intraspecific Garnacha x Tempranillo hybrids in two different locations, with the aim to assess their oenological potential and sensory attributes. Thirteen of the selections were white and 16 were red. Microvinifications were conducted with two or three replications depending on grape availability. Conventional oenological parameters were determined for all wines. The sensory evaluation and hedonic scores were given by five experts. Red selections obtained higher quality scores than white ones. Among the white selections with higher quality scores, GT-41 Varea and GT-159 Varea outstand, due to their high total acidity and high malic acid content. Regarding red selections, GT-57 Varea and GT-57 UR were perceived as higher in quality, highlighted for their moderate alcoholic and high anthocyanin content. Our results indicate that intraspecific hybridization may be a powerful tool for adapting traditional cultivars to climate change in Rioja.