GiESCO 2017 – Session 4: Vine physiology

Global warming is representing a major challenge for Mediterranean agriculture. Improving irrigation and identifying or obtaining varieties tolerant to water scarcity are being constantly pursued. In this research we contrasted 5 varieties commonly cultivated in many wine-growing areas (Merlot, Garnacha, Shyraz, Malvasia and Muscat of Alexandria) with other five varieties mainly cultivated in Andalusia, Spain (Palomino fino, Rome, Doradilla, Tinto Velasco and Pedro Ximénez).

Green pruning provides better conditions to the vegetative canopy of the vine, favoring aeration and insolation in the region of the bunches, providing better conditions for its maturation. The use of plant regulators, such as abscisic acid (ABA), has also been studied to increase the concentrations of phenolic compounds in the berry peel of the treated grapes, improving their coloration.

Grapevines are useful model plants for research on the physiology of water stress responses. Variable responses at the stomatal level have been described in different varieties with implications on the hydraulic conductance of the plant and eventually impacts on the tension imposed to the xylem architecture, depending on xylem properties. In order to assess possible associations between stomatal responses (gs) to evaporative demand (VPD), water potentials at the root to leaf gradient, plant hydraulics and xylem morphoanatomical traits, a two-season research study has been conducted in Cabernet Sauvignon (CS), Carmenere (C) and Syrah (S) in the field, under mild water stress (MWS) and well watered (WW) conditions.

The environmental sustainability of viticulture can be enhanced with the application of proper management practices (e.g. grassed inter-row), which can lead to an increase of soil carbon sequestration.

Grape acreage has been expanding rapidly in the cold regions of the U.S. However, the economic sustainability of the grape industry is hampered by freezing damage. It has long been established that sugars play a role in mediating freezing tolerance (FT) in grapes.

Climate change is affecting viticulture particularly because in wine production most of the value is provided by the desired tipicity. High air temperatures decouple grape sugars and anthocyanins accumulation impacting negatively wine composition. In this trial, carried out under the temperature-warm and semi-arid conditions of eastern Spain, we assessed two field strategies in cv. Bobal and Tempranillo aiming to delay ripening to cooler periods; 1) late leaf removal (LLR) and 2) late pruning (LP).

We wanted to quantify the importance of post-harvest carbohydrate assimilation to replenish vine reserves, additional to maintaining optimal growth, productivity and fruit quality of high yielding vigorous Sauvignon blanc grapevines.

Water limitation is one of the major threats affecting grapevine production. At the same time, grapevines are highly subjected to different viruses from which Grapevine leafroll associated virus-3 (GLRaV-3) is one of the most widespread ones.

Grapevine is a species that get along with water deficit. Yet, it cannot always stand thirst when accompanied by high temperatures, reducing noticeably its gas-exchange rates. Elucidating the origins of this reduction is a challenge, regarded the complex hydraulic, biochemical and energy processes lying behind gas-exchanges.