Efectos combinados de la clorosis férrica y el estado hídrico del viñedo en la calidad de la uva y el vino cv. Tempranillo
Water deficit and iron nutritional deficiency (iron chlorosis) are environmental stress factors that frequently affect grapevine cultivation in the Mediterranean area. Studies on the impact of both factors, when acting simultaneously, are scarce. In this Thesis, the combined effects of the incidence...
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| Formato: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2021 |
| País: | España |
| Recursos: | Universidad de Valladolid |
| Repositorio: | UVaDOC. Repositorio Documental de la Universidad de Valladolid |
| OAI Identifier: | oai:uvadoc.uva.es:10324/60389 |
| Acesso em linha: | https://doi.org/10.35376/10324/60389 https://uvadoc.uva.es/handle/10324/60389 |
| Access Level: | acceso abierto |
| Palavra-chave: | Vinos y vinificación Viticultura Wine Vino Iron chlorosis Clorosis férrica Vineyard Viñedo 3309.29 Vino |
| Resumo: | Water deficit and iron nutritional deficiency (iron chlorosis) are environmental stress factors that frequently affect grapevine cultivation in the Mediterranean area. Studies on the impact of both factors, when acting simultaneously, are scarce. In this Thesis, the combined effects of the incidence of iron chlorosis and the water status of the vine on the quality and aromatic profile of the Tempranillo grape and wine have been evaluated, and the feasibility of measuring the foliar chlorophyll content in veraison (Chl) has been studied as an early indicator of the quality potential of the grapes under these conditions. In addition, this Thesis has investigated, for the first time, how moderate levels of iron deficiency in grapevines can affect the presence of volatile organic compounds in wines. During several campaigns a group of 20 subareas of non-irrigated vineyards (10 m × 10 m each), from not affected to moderately affected by iron chlorosis, was monitored in the Ribera del Duero Designation of Origin. The water status and nutritional stress levels of the vineyard, estimated from the leaf water potential before sunrise and the foliar chlorophyll content measured at veraison, were related to the values of vigor, yield and grape composition parameters, as well as with the chemical and organoleptic characteristics of the wine. Mild to moderate incidence of iron chlorosis had no significant effects on vine vigor, yield, or berry size, but increased concentrations of some specific terpenes, C13 norisoprenoids, volatile acids, and phenols in grapes. On the other hand, the water deficit tended to increase the color intensity and the extractable anthocyanin content of the grapes. It has been observed that iron deficiency stress lowers the pH of the wine and contributes to the improvement of sensory attributes as tonality, layer intensity, flavour intensity and persistence in the mouth. Increases in red color, astringency and wine persistence associated with the incidence of iron chlorosis were observed, although restricted in conditions of high water deficit. The results show that moderate stress due to iron deficiency increased the concentrations of volatile compounds associated with floral notes, such as 2-phenylacetaldehyde, 2-phenylethanol and 2-phenylethyl acetate, in wines, while reducing the presence of C6 alcohols, responsible for the herbaceous aroma. The highest total content of phenolic compounds was observed in the vineyard subzones with the best water status. In the most stressed subzones, both due to water deficit and iron deficiency, lower contents of C6 alcohols are observed than in the less stressed subzones. The results indicate that mild to moderate iron deficiency stress can have positive effects on chemical composition and sensory attributes of Tempranillo wine. Measurements of leaf chlorophyll content at veraison could be very useful to map quality potential in rainfed vineyards affected by iron deficiency. |
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