Biotic interactions: case of grapevine cultivars – the fungal pathogen Neofusicoccum parvum – biocontrol agents 

Vitamins are major compounds, involved in several prime yeast metabolic pathways. Yet, their significance in oenology has remained mostly unexplored for several decades and our current knowledge on the matter still remaining obscure to this day. While the vitaminic contents of grape musts have been approached in these ancient investigation

Viticulture is facing two major changes – climate change and agroecological transition. In both cases, soil quality is seen as a lever to move towards a more sustainable viticulture. However, soil biological quality is little considered in the implementation of viticultural practices. Gascogn’Innov (2017-2022) is an Operational Group funded by the European Innovation Partnership for Agriculture. As such, it brings together winegrowers from the south-west of France, scientists, advisors and technicians, around a project focused on viticultural soil biological functioning and the design of technical routes more respectful toward soil heritage. To achieve this, the project aims to acquire references on the impact of viticultural practices on soil biology from a dynamic way, and to test a methodology to integrate information provided by the soil bioindicators to manage farming systems. A set of indicators of soil biological quality are evaluated in the project: microorganisms (bacteria and fungi abundance and diversity), fauna (abundance and diversity of nematodes and earthworms), physico-chemical characteristics, soil structure assessment and degradation rate of organic matter. Based on a network of 13 plots that have been subject to an initial diagnosis in 2017, several agronomical practices to restore soil fertility are experimented to redesign the cropping system (for instance plant cover, organic matter inputs, reduction of herbicides, mineral fertilizers). System redesign was made in collaboration by winegrowers and an interdisciplinary group of experts (agronomists, biologists). Several indicators are measured on vine and soil at each vintage to assess vine health and productivity. At the end of the project (2021), a final diagnosis was carried out. Gascogn’Innov allowed to create a regional database on the quality of wine-growing soils, which permitted to evaluate the effect of practices according to soil types. Especially, decreasing the intensity of tillage and increasing the duration and diversity of grass coverage tends to increase the abundance of all the organisms studied. This project confirmed the value of soil biological quality indicators to drive the sustainability of practices, but also highlighted the key-role of expertise, in both agronomy and soil biology, to help winegrowers understand and appropriate their soil quality diagnoses.

Berry maturation in warm areas takes place very early, when temperatures are still high and favorable for carbohydrate synthesis and accumulation in the berries, but not as favorable for maintaining high titratable acidity or low pH, or for increasing berry polyphenol content. Different canopy management techniques have been proven to delay berry maturation at the expense of yield (severe canopy trimming, late spring pruning to induce sprouting of dormant buds, etc.). Minimal pruning delays berry ripening by highly increasing yield and by reducing the leaf area to fruit ratio.

Aims: The aims of the present study were to (1) evaluate the water dynamics of Touriga-Nacional grapevines trained to spur pruned cordon and Guyot systems and (2) assess the effect of variable water availability in a commercial vineyard located in the Demarcated Douro Region (DDR), Portugal.

The concept of Appellation d’Origine Contrôlée (AOC) is based on the existence of a link between the characteristics of the terroir and the quality and typicality of the production (DELAS, 2000). If for a long time, this link only appeared as the fruit of empiricism, the research undertaken recently has made it possible to scientifically establish the complex relationships between the functioning of natural environments and the ability to produce quality.