Rootstock-scion contributions to seasonal water and light use diversity under field conditions

Magnesium (Mg) deficiency poses a significant challenge to viticulture, particularly affecting Welschriesling (WR), a key grape variety in Austrian and Central European vineyards.

Soils in vineyards are recognized as complex agrosystems whose characteristics reflect complex interactions between natural factors (lithology, climate, slope, biodiversity) and human activities. To date, most of the unknown lies in an incomplete understanding of soil ecosystems, and specifically in the microbial biodiversity even though soil microbiota is involved in many key functions, such as nutrient cycling and carbon sequestration. Soil biological properties are indicative of soil quality. Therefore, understanding how soil communities are related to soil ecosystem functioning is becoming an essential issue for soil strategy conservation. Here, we propose to assess the importance of land-cover history on the present-day microbiological and physico-chemical properties. The studied area was selected in the Burgundian vineyards (Pernand-Vergelesses, Burgundy, France) where land occupation has been reconstructed over the last 40 years. Soil samples were collected in five areas reflecting various land cover history (forest, vineyards, shifting from forest to vineyards). For each area, physico-chemical parameters (pH, C, N, P, grain size) were measured and DNA was extracted to characterize the abundance and diversity of microbial communities. The obtained results show significant differences in the five areas suggesting that present-day microbial molecular biomass and bacterial taxonomic is partly inherited from past land occupation. Over longer period of time, such study of land-uses legacies may help to better assess ecosystem recovery and the impact of management practices for a better soil quality and vineyards sustainability.

By using HPLC-ESI-MS, 1H, 13C and 2D NMR, new addition products between catechin, epicatechin, caftaric acid and 3SH were characterized. Caftaric acid formed more rapidly adducts with 3SH than catechin and epicatechin in the absence of other nucleophiles.

The chemical composition and the sensory characteristics of wine result from dynamic interactions between several factors including grape variety, soil, viticultural techniques, climate conditions, yeasts metabolism, oenological approaches. Recently, Grigg et al.

Dans les terroirs du Val de Loire, la précocité du cycle de la vigne et son alimentation en eau sont des variables de fonctionnement qui influent de manière importante sur la composition des baies à maturité.