Estudio de la adaptación y del comportamiento productivo y enológico de variedades blancas foráneas en la zona vitícola del Penedés

Climate change impacts water availability for agriculture, notably in semi-arid regions like South Africa, necessitating research on cultivar and rootstock adaptability to water constraints. To evaluate the performance (vegetative and reproductive) of different Chenin Blanc-rootstock combinations to the two water regimes, a field experiment was established in a model vineyard at Stellenbosch University, South Africa. Chenin Blanc vines grafted onto four different rootstocks (110Richter, 99Richter, 1103Paulsen and US 8-7) were planted in 2020. The vines are managed under two contrasting water conditions – dryland and irrigated (industry norm).

The well-known antifungal and antibiotic molecule, eugenol, is widely spread in various plants including clove, basil and bay. It is also abundant in the hybrid grapevine cultivar (cv) Baco blanc (Vitis vi-nifera x Vitis riparia x Vitis labrusca), created by François Baco (19th century) in the Armagnac region. This study confirmed this cv as highly resistant to Botrytis cinerea by comparing fruit rot incidence and severity with two Vitis vinifera cultivars: Folle Blanche and Ugni Blanc. We have demonstrated the efficiency of eugenol in vitro, by further investigating the effect of small concentrations of eugenol, 3 to 4 ppm (corresponding to IC10), on B. cinerea. By comparing the two major modes of action (direct or volatile antibiosis), the vapour inhibiting effect of eugenol was more powerful. In the skin of Baco blanc berry, the total eugenol concentration reached a maximum at veraison, i.e. 1118 to 1478 μg/kg.

Modern agriculture employs large amounts of plastics, such as mulching and greenhouse films, thermal covers, plant protection tubes and tying tape. The latter two types are very common in viticulture. Guard tubes are employed to protect young vines from mechanic and atmospheric damage, whilst polymeric tying tape has replaced natural-origin materials to hold the canopy of vines. Both materials are made on synthetic polymers, which include a range of additives to improve their environmental stability remaining in the environment of vineyards for years. During this time, they are exposed to the range of pesticides (fungicides, insecticides and in a lesser extend herbicides) applied to vines.

Fungicide spraying is a common viticultural practice that occurs throughout the growth season that protects developing vines and bunches against diseases caused by fungi or oomycetes.

Vitis vinifera L. ‘Gewürztraminer’ is a historical grape variety of Alto Adige (Südtirol), Italy, which is widely grown in the area of Tramin an der Weinstraße, but is also grown globally. It produces highly aromatic wines that are strongly influenced by the terroir of the vineyard sites where they are grown. This study looked at musts and young wines from ‘Gewürztraminer’ grapes harvested in seven distinct vineyards near Tramin and then processed at Cantina di Termeno, minimizing winemaking protocol variability. Samples were profiled using bidimensional gas chromatography–time-of-flight mass spectrometry, liquid chromatography coupled to electrochemical detection, and near-IR spectrometry. The data were subjected to Principle Component Analysis and Hierarchical Clustering Analysis. Sensory discriminant testing was undertaken using the sorting method with a semi-trained panel, and the data were processed using Multidimensional Scaling. Seven must/wine pairs could be distinguished based on their untargeted volatilome profiles and on sensory evaluation. As expected, there were greater differences in the volatile compounds between the wines than between the musts. The wines from vineyards 4 and 5 were nonetheless quite homogenous in terms of chemical and sensory analyses, as were the wines from vineyards 1 and 3. For the phenolic profile, differences were noted between the musts and wines of vineyards 2, 3, and 4, but the musts from vineyards 5 and 7 were similar. Sensory analysis showed the wines from vineyards 6 and 7 to be distinct from the rest. These results reinforce that the composition of ‘Gewürztraminer’ musts and wines is strongly determined by vineyard site, even in a small geographic area with high variability of the terroir (soil and microclimate), and that these differences are apparent in the flavours and aromas of the finished wines. Further confirmation would require a larger sample of wines, preferably from several vintages.