Winter physiology in a warmer world: Cold hardiness and deacclimation sensitivity drive variation in spring phenology

Free amino acid concentrations in must of 7 Vitis vinifera cultivars (Cabernet Franc, Syrah, Merlot, Montepulciano, Sangiovese, Cesanese d’Affile, Carmenere) grown in the Latium region (Italy) were monitored from 2003 to 2005. The cultivars were located in a homogeneous soil and climatic zone and with the same training system (Cordon Spur).

During Champagne or sparkling wine tasting, gas-phase CO2 and volatile organic compounds invade the headspace above glasses [1], thus progressively modifying the chemical space perceived by the consumer. Gas-phase CO2 in excess can even cause a very unpleasant tingling sensation perturbing both ortho- and retronasal olfactory perception [2]. Monitoring as accurately as possible the level of gas-phase CO2 above glasses is therefore a challenge of importance aimed at better understanding the close relationship between the release of CO2 and a collection of various tasting parameters.

Grapevine rootstocks have traditionally been chosen in order to manage scion vigour, soil pests and soil conditions. Riparia Gloire de Montpellier (RGM) has been in use since the turn of the 19th century, over 100 years and still a remarkably stable source of phylloxera (Daktulosphaeria vitifoliae Fitch) resistance. The original source material was probably collected near the Missouri/Mississippi river confluence, a mid-continental but more southerly location in the United States. It has been hypothesized that more northerly selections of V. riparia Michx might improve both fall acclimation rate and depth of the scion, thus mitigating late fall frost and midwinter freeze damage.

Commercial grape production relies on training grapevine cultivars onto a variety of trellis systems. Training allows for well-lit leaves and clusters, maximizing fruit quality in addition to facilitating cultivation, harvesting, and diseases control. Although grapevines can be trained onto an infinite variety of trellis systems, most red and white cultivars are trained to the standard VSP (Vertical Shoot Positioning) system. However, red and white cultivars respond differently to VSP in fruit composition and growth characteristics, which are yet to be fully understood. Therefore, the objective of this study was to examine the influence of the VSP trellis system on fruit composition of three red, Cabernet Sauvignon, Merlot and Syrah, and three white, Chardonnay, Riesling, and Gewurztraminer cultivars grown under uniform growing conditions in the same vineyard. All cultivars were monitored for maturity and harvested at their physiologically maximum possible sugar concentration to compare various fruit quality attributes such as Brix, pH, TA, malic and tartaric acids, glucose and fructose, potassium, YAN, and phenolic compounds including total anthocyanins, anthocyanin profile, and tannins. A distinct pattern in fruit composition was observed in each cultivar. In regards to growth characteristics, Syrah grew vigorously with the highest cluster weight. Although all cultivars developed pyriform seeds, the seed size and weight varied among all cultivars. Also varied were mesocarp cell viability, brush morphology, and cane structure. This knowledge of the canopy architectural characteristics assessed by the widely employed fruit compositional attributes and growth characteristics will aid the growers in better management of the vines in varied situations.

Increasing concentrations of greenhouse gases (GHGs) in the atmosphere due to human activities are leading to a rise in the average temperature of the atmosphere. among the scenarios established by the un’s intergovernmental panel on climate change (IPCC), only two enable us to achieve the minimum objective of the paris agreements signed at cop 21 in 2015: staying below +2°c after 2050. both scenarios forecast a rapid reduction in GHG emissions as early as 2025, thanks to strong international cooperation, the priority given to sustainable development and responsible consumer choices.