Grape development revisited through the single-berry metabolomic clock paradigm

Dans le cadre d’une recherche sur les terroirs viticoles du canton de Vaud – Suisse, un modèle du microclimat intégrant température, relief, éclairement et pluviométrie a été conçu.

Chile, junto con Australia, EE.UU., Sudáfrica, Argentina y Nueva Zelanda constituye el grupo de países del nuevo mundo vitivinícola. Todos ellos en conjunto han experimentado en la última década

Le Dipartimento di Progettazione dell ‘Architettura del Politecnico di Milano et l’Istituto di Viticoltura della Facoltà d’Agraria di Piacenza dell’Università Cattolica del Sacra Cuore, ont elaboré une proposition pour réaliser, dans l’aire de colline de la province de Piacenza, un Parco Produttivo Agrovitivinicolo.

In the last decades, climate change required already adaptation of vineyard management. Increase in temperature and unexpected weather events cause changes in all phenological stages requiring new management tools. For example, defoliation can be a useful tool to reduce the sugar content in the berries creating differences in the wine profiles. In a ten-year field experiment using Riesling (Vitis vinifera L, planted 1986, Geisenheim, Germany), various mechanical defoliation strategies and different intensities were trialed until 2016 before the vineyard was uprooted. Wood was sampled from the plant compartments root, trunk, cordon and shoot for analyses of physicochemical properties (e.g. lignin and element content, pH, diameter), nonstructural carbohydrates and the microbial communities. The aim of the study was to investigate the influence of reduced canopy leaf area on the sink-source allocation into different compartments and potential changes of the fungal and prokaryotic wood-inhabiting community using a metabarcoding approach. Severe summer pruning (SSP) of the canopy and mechanical defoliation (MDC) above the bunch zone decreased the leaf area by 50% compared to control (C). SSP reduced the photosynthetic capacity, which resulted in an altered source-sink allocation and carbohydrate storage. With lower leaf area, less carbohydrates are allocated. This for example resulted in a decreased trunk diameter. Further, it affected the composition of the grapevine wood microbiota. SSP and MDC management changed significantly the prokaryotic community composition in wood of the root samples, but had no effect in other compartments. In general, this study found strong compartment and less management effects of the microbial community composition and associated physicochemical properties. The highest microbial diversities were identified in the wood of the trunk, and several species were recorded the first time in grapevine.

The last step in winemaking is packaging the wines for market placement, while preserving the quality attained during vinification. Since the 1980s, 2,4,6-trichloroanisole (TCA) has been recognised as an incidental and random contaminant of cork, with its migration into wine thought to contribute to ‘cork taint’. This molecule is not a cork component and little is known about how it is formed on trees. Its formation from the chlorine used to wash the cork stoppers, long suspected, has been excluded by the abandonment of chlorine washing.