Heat berry: the influence of abiotic factors on the composition of berries, must and wine in Vitis vinifera L. CV Riesling

Air temperature is the key driver of grapevine phenology and a significant environmental factor impacting yield and quality for a winegrape growing region. In this study the optimal downscaled CMIP5 ensemble for computing thegrowing season average temperature (GST) viticulture climate classification index was determined to spatially compute on a decadal basis predictions of the GST climate index and the grapevine sugar ripeness (GSR) model for Pinot Noir throughout the Willamette Valley (WV) American Viticultural Area (AVA). Forecasts for average temperature and a 220 g/L target sugar concentration level were computed using daily Localized Constructed Analogs (LOCA) downscaled CMIP5 historic and Representative Concentration Pathways (RCP) future climate projections of minimum and maximum daily temperature. We explore spatiotemporal trends of the GST climate classification index and Pinot Noir specific applications of the GSR phenology model for the WV AVA. Spatiotemporal computations of the GST climate index and Pinot Noir specific applications of the GSR model enable the opportunity to explore relationships between their computed values with one intent being to provide updated GST ranges that better align with current temperature-based modeling understanding of Pinot Noir grapevine phenology and the viticultural application of LOCA CMIP5 climate projections for the WV AVA. The Pinot Noir specific applications of the GSR model or the GST index with updated bounds indicate that the percent of the WV AVA area suitable for Pinot Noir production is currently at or near its peak value in the upper 80s to lower 90s of this century.

Foliar application of urea may be an efficient way to alter grape and wine composition without increasing vine vigor. However, we know little about the impact of this practice on phenolic compounds and yeast assimilable nitrogen (YAN). Adequate YAN is required for an efficient and complete fermentation, while phenolics are particularly important for the sensory profile of red wines. The goal of this study is to test the impact of foliar urea application at veraison, compared to the traditional soil-applied nitrogen fertilization early in the season, on Syrah berry and wine composition in field conditions.

Nitrogen (N) is quite important nutrient in grapevine development and must quality, but under Mediterranean climatic conditions, available soil water (ASW) during grapevine development can also influence vigour and must quality. The aim was to determine the influence of soil nitrate (NO3-) availability on N foliar, yield, and must quality in vineyards with similar available water holding capacity (AWC). For this purpose, four cv. Tempranillo (Vitis vinifera L.) vineyards were selected. All of them are placed in Uruñuela municipality (La Rioja, Spain), separated less than 2.5 km and in a slope <1 %, in soils with similar soil chemistry properties and with similar rooting depth (ranging between 105 cm and 110 cm).

Nowadays, many policies are being adopted for direct agriculture towards more sustainable approaches. To continue to maintain a high production using fewer fertilizers, pesticides and water resources, agronomic techniques must be combined with biotechnological approaches. In grapevine, the breeding programs are restricted by the fact that it has a highly heterozygous genome, therefore, if on the one hand, we try to improve the characteristics, on the other hand it is necessary to preserve the original genome of the varieties. CRISPR-cas9 system is one of the smartest tools to carry out highly precise genetic modifications leaving the genetic background unchanged.

Le régime thermique en période de maturation du raisin est l’une des variables déterminantes de la coloration du raisin et de la richesse en arômes, anthocyanes et polyphénols des vins.