Effets des pratiques agro-viticoles sur l’activité biologique et la matière organique des sols : exemples en Champagne et en Bourgogne

San Joaquin Valley accounts for 40% of wine grape acreage and produces 70% of wine grape in California. Fruit quality is one of most important factors which impact the economical sustainability of farming wine grapes in this region. Due to the recent drought and expected labor cost increase, the wine industry is thrilled to understand how to improve fruit quality while maintaining the yield with less water and labor input. The present study aims to study the interactive effects of mechanical leafing and deficit irrigation on yield and berry compositions of Cabernet Sauvignon grown in warm climate of California.

The species and origin used for red wine oak aging determines the physiological composition of the wood and thus the finished wines. In America, oak is grown primarily in the states of Virginia, Missouri, Kentucky, Oregon, Ohio, Minnesota, Wisconsin and California. The aim of this study was to analyze how the choice of barrels made with Quercus Alba oak from different geographic areas of the United States (Missouri, Kentucky, Ohio and Pennsylvania) influences the polyphenolic composition of Tempranillo red wines.

This study evaluates the effect of microwave treatment in grape maceration on the content of free and glycosidically bound varietal compounds) of must and wine and on the overall aroma of wines produced in the presence and absence of SO2.

Grapevine breeding is part of the research program of Agroscope in Switzerland since 1965. From 1965 to 1995, the aim of the Vitis vinifera crosses was to obtain a high resistance to grey rot (Botrytis cinerea), one of the most virulent fungal pathogens in the Swiss vineyard. In 2021, the grape varieties released from this first breeding program covered 936 ha of the 15’000 ha of the Swiss vineyard.
In 1996, a second breeding program aimed at obtaining, by classical interspecific hybridization, grape varieties resistant to downy mildew (Plasmopara viticola) and powdery mildew (Erisyphe necator) and less sensitive to grey rot (Botrytis cinerea). In order to accelerate and make the selection process more reliable, an early biochemical test was developed based on the natural defense mechanisms of the vine against downy mildew (stilbene phytoalexins). The synthesis of stilbenes (i.e., resveratrol and its oxidized dimers - and -viniférine) and pterostilbenes (methylated derivative) is among the most efficient induced defense mechanisms of grapevine against fungal pathogens on both the leaves and the clusters.

Context and purpose of the study – Viticulture faces significant challenges due to climate change, with increased frequency of extreme weather events impacting grapevine growth, grape quality, and wine production.