Altered lignans accumulation in a somatic variant of Tempranillo with increased extractability of polyphenols during winemaking

Cover crops are increasingly considered in Mediterranean climate vineyards due to a combination of agronomic and regulatory considerations. However, the soil under the vines themselves is typically kept free of vegetation by mechanical plowing or herbicide spraying. Taking into account that these practices may convey a number of non-favourable economic and environmental implications, and the fact that drip irrigation can ease the use of cover crops under the vines, the aim of this work was to evaluate the agronomic implications and the changes in soil physical and biological properties caused by an under-vine cover crop in a Mediterranean area.

In the present work Schizosaccharomyces japonicus and Saccharomyces cerevisiae were inoculated simultaneously or in sequence in mixed fermentation trials with the aim of testing their ability to improve the overall quality of red wine

As viticulture faces challenges such as climate change or vineyard dieback, the choice of the variety and rootstock becomes more and more crucial. To study rootstock levers in the Bordeaux region, a parcel of Cabernet Sauvignon (CS) was planted with four rootstocks in 2014. Twenty repetitions of each of the following four rootstocks were set up: 101-14 MGt, Nemadex AB, 420A MGt and Gravesac. The number of bunches, yields and pruning weights of the vine shoots were measured individually on 240 vines from 2017 to 2021. Since 2020, nitrogen status assessed by assimilable nitrogen level, hydric status assessed by δ13C and berry maturity were measured on 80 samples taken from 20 repetitions of the four rootstocks. A lower yield was measured for CS grafted onto Nemadex AB due to the lower number of bunches and the lower weight of berries. The differences between the other three rootstocks are small, but CS grafted onto 420A MGt was the most productive. The CS grafted onto Nemadex AB had the lowest pruning weight while 101-14 MGt had the highest. In 2020, δ13C showed a more moderate water stress with 101-14 MGt and 420A MGt than with Nemadex AB. Surprisingly, the Gravesac was under more stress than the 101-14 MGt. The nitrogen status in the berries was better for Nemadex AB but this was perhaps due to the significantly lower weight of the berries.Rootstock 101-14 MGt attained the highest accumulation of sugars in the berries while 420A MGt allows to preserve higher acidity. The parcel is still young which may explain some of the results. These measures must therefore be continued over the next several years to fully assess the effects of these rootstocks on the development of the vines and the quality of the production under new climatic conditions.

Climate change has been influencing viticulture and changing wine profiles in the past years, and effects are expected to get worse.

This presentation aims to demonstrate that the value attributed to wine as we today know it is based on three factors: 1) sensory balance, 2) personality, and 3) bioactivity.