Impact of malolactic fermentation on volatile composition and sensory properties of white and rosé wine from the greek variety moschofilero

Nitrogen (N2) is critical in grape berries, especially in organic wine making. After intake, N2 follows various metabolic and allocation routes and, from veraison, partly reallocates into berries. Water deficit affects the N2 nutrition due to a poor diffusion in soil solution and vascular mobilisation. Also, affects photosynthesis and the energy needed for metabolism, whose extent would depend on the stomatal sensitivity of the plant. We have assessed the effect of a moderate water deficit from pea size, in 3 years old field grown potted plants of Chardonnay (CH) and Cabernet Sauvignon (CS), differing in stomatal sensitivity, on the N2 status of plant parts. Water deficit reduced photosynthesis, leaf area and fresh and dry plant mass along the season, but up to a higher extent in CS.

Esca is a grapevine vascular disease with detrimental consequences on vineyard yield and longevity. Recently, esca leaf symptom development has been shown to result in the occlusion of xylem vessels by tyloses in leaves and stems, leading to hydraulic failure. However, little is known regarding the response of xylem anatomy and stem growth to esca in different varieties . Here we studied the impact of esca leaf symptom development on grapevine physiology, stem growth, and xylem anatomy in two widespread cultivars, Cabernet sauvignon and Sauvignon blanc.

Germicidal ultraviolet-C (UV-C) light has shown promising results for suppression of several plant-pathogenic microorganims, including Erysiphe necator, which attacks grapevine. In Washington State the majority of winegrape production is in a semi-arid steppe environment, with historically low powdery mildew disease pressure, making it a promising area to deploy UV-C as a disease management tool. Trials focusing on UVC application timing and frequency will assist in developing regionally-appropriate application recommendations for eastern Washington State.

Riesling represents the most widely cultivated grape variety in Germany and is therefore of particular economic interest. During recent years an increase in the petrol-note as well as in undesirable bitter and adstringent notes has been reported. These changes are most likely linked to increasing temperature and sunlight exposure of grapes due to climate changes.
The “petrol note” is caused by the formation of the C13-norisoprenoid 1,1,6-trimethyl-1,2-dihydronaphthalin (TDN), which originates from acid-labile precursors formed by the carotenoid degradation in the grape.

A 3-year zoning study promoted by the Cooperative Winery Valpolicella (Negrar, Verona, Italy) was carried out on a wine territory of about 500 ha.