Étude intégrée et allégée des terroirs viticoles en Anjou: caractérisation et zonage de l’unité terroir de base, en relation avec une enquête parcellaire

Context and Purpose of the Study. The use of herbicides and mechanical soil tillage, particularly on steep slopes, poses significant ecological challenges, including soil compaction and erosion.

A large varietal collection including over 1700 varieties was maintained in Conegliano, ITA, since the 1950s. Phenological data on a subset of 400 grape varieties including wine grapes, table grapes, and raisins were acquired at bud break, flowering, veraison, and ripening since 1964. Despite the efforts in maintaining and acquiring data over such an extensive collection, the data set has varying degrees of missing cases depending on the variety and the year. This is ubiquitous in phenology datasets with significant size and length. In this work, we evaluated four state-of-the-art methods to estimate missing values in this phenological series: k-Nearest Neighbour (kNN), Multivariate Imputation by Chained Equations (mice), MissForest, and Bidirectional Recurrent Imputation for Time Series (BRITS). For each phenological stage, we evaluated the performance of the methods in two ways. 1) On the full dataset, we randomly hold-out 10% of the true values for use as a test set and repeated the process 1000 times (Monte Carlo cross-validation). 2) On a reduced and almost complete subset of varieties, we varied the percentage of missing values from 10% to 70% by random deletion. In all cases, we evaluated the performance on the original values using normalized root mean squared error. For the full dataset we also obtained performance statistics by variety and by year. MissForest provided average errors of 17% (3 days) at budbreak, 14% (4 days) at flowering, 14.5% (7 days) at veraison, and 17% (3 days) at maturity. We completed the imputations of the Conegliano dataset, one of the world’s most extensive and varied phenological time series and a steppingstone for future climate change studies in grapes. The dataset is now ready for further analysis, and a rigorous evaluation of imputation errors is included.

If one considers as “physical or sensory attributes” of a wine its concentrations of alcohol and of other substances, it can be stated that another class of attributes exists

In vitro culture makes it possible to carry out specific studies that would not be possible with whole plants grown in the field or in a greenhouse. Cryopreservation allows long-term preservation without metabolic changes in the plant material and cryotherapy can be efficient in virus elimination, which is a major scientific challenge.
The preculture media of cryopreservation protocols were evaluated on three Croatian grape varieties with different antioxidants (salicylic acid, ascorbic acid and glutathione). The highest growth in vitro was achieved on the medium with the addition of glutathione and the lowest with the addition of salicylic acid.

Kombucha is a non-alcoholic beverage made of sugared tea that is transformed by a symbiotic consortium of yeasts and bacteria. This beverage is increasingly produced at industrial scale, but its quality standards remain to be defined. Metabolomics analysis was carried out using FT-ICR-MS to understand the chemical transformations induced by the production phases and the type of tea on