Abstract
Grapevine flowers development and fruit set are both influenced by cold nights in the vineyard. In this study, impact of chilling temperatures (0°C overnight) on carbon metabolism was investigated in the inflorescences of two cultivars, Pinot noir (PN) and Gewurztraminer (GW), selected according to their distinct sensitivity to the “coulure” process, GW being the most sensitive.

The goal of our study was to improve Tannat grapes and wine composition, by achieving vine balance. We propose a change in the current Uruguayan grape-growing paradigm that accepts unpredictable periods of water deficit or excess in non-irrigated vineyards applying herbicides to eliminate weeds competition. We used an under-trellis cover crop (UTCC) to limit vine water availability, reduce vine growth rate and final canopy size.

In vascular plants, water is transported in a metastable form below its vapor pressure in xylem tissue. Under high tensions (negative pressures), the stability of the water column can be broken by the irruption of air bubbles in the xylem, a phenomenon called cavitation.

Recent studies have shown that models, which can partition solar radiation between grapevines and soil are valuable tools to correspondingly separate potential evapotranspiration and to derive an expression for the potential transpiration of grapevines.

It has long been believed that ripening grape berries become dependent upon phloem water supply because xylem flow into the berries ceases at veraison due to rupture of vessels during rapid berry expansion. We provide evidence that this hydraulic isolation dogma should be replaced by a new model.

In Australia, Thompson Seedless is a popular table grape variety for domestic and export markets. However, incidences of berry collapse in 3 seasons resulted in significant financial losses to fresh grape producers (e.g. $Aus100 million in 2008). Berry collapse symptoms become visually obvious around véraison with development of striated necrotic (dead) tissue in the berry skin, berry discolouration and collapse, predominantly at the distal end of the berry, with an apparent loss of moisture.

Environmental benefits of permanent cover crop in vineyard are well known. Nevertheless, permanent cover cropping is quite rare in French Mediterranean vineyards, because there is a risk of severe drought during summer, and consequently yield losses. Over the past few years, irrigation has developed in this area, offering new possibilities for better control of grapevine water status in cover cropped vineyards.

The aim of this paper is to present preliminary results (two seasons 2013-2014) forming part of a long term investigation on the effects of using treated wastewater for irrigation of grapevines Vitis vinifera cv. Viognier B and Carignan N. The experimental plots are established on limestone and sandy loam soils and grown under Mediterranean conditions of southern France.

By monitoring plant water use continuously, new irrigation techniques can be implemented to promote more efficient vineyard water use. In order to demonstrate the impact of a new plant-based irrigation method in terms of water savings and vineyard performances, we designed an experiment across multiple vineyards in contrasted climatic condition during a very dry season.

Water availability is considered a determinant factor for grape-growing sustainability since vineyard water relations critically impacts on vine performance and grape and wine composition. Improving water use efficiency (WUE) is therefore of crucial importance for a sustainable viticulture in Mediterranean and semi-arid regions.

Grapevine yield sustainability under global warming is a major issue. A hypothesis is that long-term elevated temperatures may cause the failure of key phases of reproductive development, through their negative impact on carbon balance. However, testing the specific role of plant carbon status on yield elaboration under elevated temperatures is difficult on perennial crops, such as grapevine, and when environment fluctuates.

Radiation is one of the main environmental variables that determine leaf microclimate within the vine, and consequently its photosynthesis and carbohydrate metabolism. The objective of this study was to comprehend the relationships among photosynthetic performance, carbohydrate metabolism, and related gene expression of grapevine leaves grown under different radiation regimes.