Diversity of leaf functioning under water deficit in a large grapevine panel: high throughput phenotyping and genetic analyses

Stomatal traits determine grapevine water use, carbon supply, and water stress, which directly impact yield and berry chemistry. Breeding for stomatal traits has the strong potential to improve grapevine performance under future, drier conditions, but the trait values that breeders should target are unknown. We used a functional-structural plant model developed for grapevine (HydroShoot) to determine how stomatal traits impact canopy gas exchange, water potential, and temperature under historical and future conditions in high-quality and hot-climate California wine regions (Napa and the Central Valley). Historical climate (1990-2010) was collected from weather stations and future climate (2079-99) was projected from 4 representative climate models for California, assuming medium- and high-emissions (RCP 4.5 and 8.5). Five trait parameterizations, representing mean and extreme values for the maximum stomatal conductance (gmax) and leaf water potential threshold for stomatal closure (Ψsc), were defined from meta-analyses. Compared to mean trait values, the water-spending extremes (highest gmax or most negative Ysc) had negligible benefits for carbon gain and canopy cooling, but exacerbated vine water use and stress, for both sites and climate scenarios. These traits increased cumulative transpiration by 8 – 17%, changed cumulative carbon gain by -4 – 3%, and reduced minimum water potentials by 10 – 18%. Conversely, the water-saving extremes (lowest gmax or least negative Ψsc) strongly reduced water use and stress, but potentially compromised the carbon supply for ripening. Under RCP 8.5 conditions, these traits reduced transpiration by 22 – 35% and carbon gain by 9 – 16% and increased minimum water potentials by 20 – 28%, compared to mean values. Overall, selecting for more water-saving stomatal traits could improve water-use efficiency and avoid the detrimental effects of highly negative canopy water potentials on yield and quality, but more work is needed to evaluate whether these benefits outweigh the consequences of minor declines in carbon gain for fruit production.

The composition and structure of vineyard landscapes significantly affect bird communities and the ecosystem services they provide in agriculture.

New Zealand viticulture has long been characterised by sustainable grape growing practices as promoted by Sustainable Winegrowing New Zealand (SWNZ) as well as by Organic Viticulture.

Clay-based ceramic vessels (jars, pyhtoi, etc.) for wine fermentation and aging processes have been used in several cultures for millennia. This know-how still in practice in several countries of the Armenian highland is gaining worldwide in curiosity, popularity, and interest. Ceramic pots are famous among traditional winemakers for their benefits such as temperature regulation, natural cooling system, favorable oxygen exchange, and impact on pH, which are different from those of stainless steel, wood barrels, or concrete.

The use of varieties tolerant to diseases is a long-term but promising option to reduce chemical input in viticulture. Several important breeding programs in Europe and abroad are starting to release a range of new hybrids performing well regarding fungi susceptibility and wine quality.