Heat requirements for grapevine varieties is essential information to adapt plant material in a changing climate

Aim: Pinot Blanc is the third most planted white wine grape in northern Italy’s region of South Tyrol, where small-scale viticultural production permits the examination of the wine’s diverse expressive potential in a small area across a wide range of climatic variables. This study aimed to explore the qualitative potential of Pinot Blanc across a range of climatic variation leading to site-specific terroir expression in a cool climate region.

AIM: Grape flavanols are involved in wine quality markers such as in-mouth sensations and colour stability.

The pinking is a phenomenon that can occur in white wine produced with white grape causing the color change from yellow to red-salmon hue. Even if its appearance is highly variable and dependent to the vintage, the wines from certain grape varieties, such as Sauvignon blanc, Chardonnay, Riesling and Trebbiano di Lugana, have been identified to be more susceptible to the pinking.

Late spring frost is a major challenge for various winegrowing regions across the world, its occurrence often leading to important yield losses and/or plant failure. Despite a significant increase in minimum temperatures worldwide, the spatial and temporal evolution of spring frost risk under a warmer climate remains largely uncertain. Recent projections of spring frost risk for viticulture in Europe throughout the 21st century show that its evolution strongly depends on the model approach used to simulate budburst. Furthermore, the frost damage modelling methods used in these projections are usually not assessed through comparison to field observations and/or frost damage reports.
The present study aims at comparing frost risk projections simulated using six spring frost models based on two approaches: a) models considering a fixed damage threshold after the predicted budburst date (e.g BRIN, Smoothed-Utah, Growing Degree Days, Fenovitis) and b) models considering a dynamic frost sensitivity threshold based on the predicted grapevine winter/spring dehardening process (e.g. Ferguson model). The capability of each model to simulate an actual frost event for the Vitis vinifera cv. Chadonnay B was previously assessed by comparing simulated cold thermal stress to reports of events with frost damage in Chablis, the northernmost winegrowing region of Burgundy. Models exhibited scores of κ > 0.65 when reproducing the frost/non-frost damage years and an accuracy ranging from 0.82 to 0.90.
Spring frost risk projections throughout the 21st century were performed for all winegrowing subregions of Bourgogne-Franche-Comté under two CMIP5 concentration pathways (4.5 and 8.5) using statistically downscaled 8×8 km daily air temperature and humidity of 13 climate models. Contrasting results with region-specific spring frost risk trends were observed. Three out of five models show a decrease in the frequency of frost years across the whole study area while the other two show an increase that is more or less pronounced depending on winegrowing subregion. Our findings indicate that the lack of accuracy in grapevine budburst and dehardening models makes climate projections of spring frost risk highly uncertain for grapevine cultivation regions.

The regulation of weeds, particularly in the under-vine area of grapevines, is essential for the maintenance of grape yield and quality.