Obtaining new varieties derived from Monastrell for the preparation of low alcoholic wines

In April 2024, the French official catalog includes 449 grape varieties and rootstocks. In 10 years it has been enriched with 70 varieties. It is an indisputable marker of the interest of professionals in genetic resources of all origins and the expectations they have to prepare the viticulture of the future. The scientific community has now put all irons in the fire and is not neglecting any avenue of adaptation. The regular decline in the use of phytosanitary products and the already marked effects of climate change are the targets of varietal improvement.

The development of interspecific hybrid varieties (ihvs) resistant to diseases such as powdery mildew and downy mildew allows for a decrease in the use of inputs in vineyards. In this pers-pective, ihvs represent a response to societal demand for reducing environmental impact and are increasingly used in viticulture. At the same time, wines resulting from so-called sponta-neous fermentations, based on indigenous flora, have recently gained popularity.

3-Isobutyl-2-methoxypyrazine (IBMP) is one of the key molecules in wine aroma with a bell pepper aroma and a very low threshold in wine, 1-6 ng/L for white wine and 10-16 ng/L in red wine1. The differences in these thresholds are likely due to IBMP-non volatile matrix interactions. It has indeed been shown that polyphenols may influence the volatility of flavor compounds2. In the present study, we focus on IBMP-polyphenols interactions in relation to volatility and sensory perception in model wine solution. Methods: 1. GC-MS Static Headspace Analysis: Samples were analyzed by Static headspace analysis with an Agilent 7890A gas chromatograph coupled to HP 5975C mass spectrometry detector (Agilent Technologies, Santa Clara, CA, USA).

Pomace and grape stems are the main solid organic waste from winery industries, resulting from the pressing and/or fermentation processes it is generated in large amounts in many parts of the world

Optimizing the use of water and improving irrigation strategies has become increasingly important in most winegrowing countries due to the consequences of climate change, which are leading to more frequent droughts, heat waves, or alteration of precipitation patterns. Optimized irrigation scheduling can only be based on a reliable knowledge of the vineyard water status.

In this context, this work aims at the development of a novel methodology, using a contactless, miniaturized, low-cost NIR spectral tool to monitor (on-the-go) the vineyard water status variability. On-the-go spectral measurements were acquired in the vineyard using a NIR micro spectrometer, operating in the 900–1900 nm spectral range, from a ground vehicle moving at 3 km/h. Spectral measurements were collected on the northeast side of the canopy across four different dates (July 8th, 14th, 21st and August 12th) during 2021 season in a commercial vineyard (3 ha). Grapevines of Vitis vinifera L. Graciano planted on a VSP trellis were monitored at solar noon using stem water potential (Ψs) as reference indicators of plant water status. In total, 108 measurements of Ψs were taken (27 vines per date).

Calibration and prediction models were performed using Partial Least Squares (PLS) regression. The best prediction models for grapevine water status yielded a determination coefficient of cross-validation (r2cv) of 0.67 and a root mean square error of cross-validation (RMSEcv) of 0.131 MPa. This predictive model was employed to map the spatial variability of the vineyard water status and provided useful, practical information towards the implementation of appropriate irrigation strategies. The outcomes presented in this work show the great potential of this low-cost methodology to assess the vineyard stem water potential and its spatial variability in a commercial vineyard.