Metabolomics of Vitis davidii Foëx. grapes from southern China: Flavonoids and volatiles reveal the flavor profiles of five spine grape varieties

Pinking describes the appearance of a salmon-red blush in white bottled wines produced exclusively from white grape varieties. It is understood as an undesirable chromatic phenomenon by both wine consumers and the industry. Nowadays, there are no treatments to fully reverse pinking once it occurs. Partial reversion has been shown after exposure of pinked wine to ultraviolet (UV) light.

Climate change impacts water availability for agriculture, notably in semi-arid regions like South Africa, necessitating research on cultivar and rootstock adaptability to water constraints. To evaluate the performance (vegetative and reproductive) of different Chenin Blanc-rootstock combinations to the two water regimes, a field experiment was established in a model vineyard at Stellenbosch University, South Africa. Chenin Blanc vines grafted onto four different rootstocks (110Richter, 99Richter, 1103Paulsen and US 8-7) were planted in 2020. The vines are managed under two contrasting water conditions – dryland and irrigated (industry norm).

There is an urgent need in viticulture to adopt alternative herbicide-free soil management strategies to mitigate climate change, increase biodiversity, reduce plant protection products and improve soil quality while minimizing detrimental effects on grapevine’s stress tolerance and fruit quality. To propose sustainable solutions, adapted to different pedoclimatic conditions in Switzerland, we developed a multidisciplinary 4-year project, started in 2020. Objectives of the project are to a) evaluate the impact of green covers (spontaneous flora, winter cover crop and permanent ground cover) on environmental and agronomic parameters and b) develop subsequently innovative strategies for different viticultural contexts of Switzerland. The project is divided into 3 phases: 1) diagnosis, 2) on-farm and 3) on-station experiments. Phase 1) consisted in an assessment of 30 commercial vineyards all over Switzerland, where growers already use different herbicide-free soil management strategies. The most promising practices identified in this exploratory phase will be replicated in commercial vineyards across Switzerland (“on-farm”) as well as in a classical randomized block design in an experimental plot (“on-station”). For phase 1), measurements consisted in evaluation of soil status (compaction, structure, roots development), soil microbial diversity (metagenomics), plant diversity and biomass, vine physiology (water stress, vigor, leaf nitrogen) and berry quality (acidity, sugar, available nitrogen). Interestingly, the permanent ground cover resulted in a higher Shannon index thus a higher biodiversity as compared to the other itineraries. The winter cover crop increased vine nitrogen and vigor while deteriorating soil quality, leaving the soil more exposed and compacted likely due to more frequent tillage. The spontaneous flora led to higher berry sugar accumulation, less nitrogen and higher malic acid concentration putatively due to a higher water retention of the flora in a particularly wet vintage. Phases 2) and 3) are required to confirm those tendencies, over the 3 next vintages and different climatic conditions.

Two transmittance-based chlorophyll meters (SPAD-502 and CCM-200) were evaluated in estimating chlorophyll (Chl) and nitrogen (N) levels in grapevine leaves.

The Columbia Gorge Wine Region (CGWR) extends for about 100km along the Columbia River and includes the Columbia Gorge American Viticultural Area (AVA) and the southwest portion of the Columbia Valley AVA.