Postharvest ozone treatment in grapevine white cultivars: Effects on grape volatile composition

AIM: The refractive index is a basic optical property of materials and a key tool for the determination of major components in musts, such as sugars

One of the main consequences of global warming is the rise of the mean temperature. Thus, the heat summation by the plants begins sooner in the early spring, and by cumulating growing degree-days, phenological development tends to happen earlier. However, spring frost is still a recurrent phenomenon causing serious damages to buds and therefore, threatening the harvests of the winegrowers. The wind machine is a solution to protect fruit crops against spring frost that is increasingly used. It is composed of a 10-m mast with a blowing fan at its peak. By tapping into the strength of the nocturnal thermal inversion, it sweeps the crop by propelling warm air above to the ground. Thus, stratification is momentarily suppressed. Furthermore, the continuous action of the machine, alone or in synergy, or the addition of a heater allow the bud to be bathed in a warmer environment. Also, the punctual action of the tower’s warm gust reaches the bud directly at each rotation period. All these actions allow the bud to continuously warm up, but with different intensities and over a different period. Although there is evidence of the effectiveness of the wind machines, the thermal transfers involved in those mechanisms raise questions about their true nature. Field measurements based on ultrasonic anemometers and fast responding thermocouples complemented by laboratory measurements on a reduced scale model allow to characterize both the airflow produced by the wind machine and the local temperature in its vicinity. Those experiments were realized in the vineyard of Quincy, in the framework of the SICTAG project. In the future paper, we will detail the aeraulic characterization of the wind machine and the thermal effects resulting from it and we will focus on how the wind machine warms up the local atmosphere and enables to reduce the freezing risk.

The climate change is afecting particulary to the South of Spain, with high temperatures. It is important to develop new strategies in order to mantain the quality of wines

Xinomavro is the most important indigenous red wine variety grown in Northern Greece. It participates in the production of several PGI wines in Macedonia while from 100% Xinomavro the PDO “Amyndeon” and “Naoussa” are produced. The viticultural area of Amyndeon lies in a plateau of 550 ‐700 m of altitude, in a semi‐continental climate with mostly deep sandy loamy soils derived from limestone and marl bedrocks while in Naoussa, Xinomavro is grown in a Mediterranean climate on more heavy textured soils, sandy clay loam to clay, derived from ophiolithic, limestone and marl bedrocks, in an altitude which varies from 150 to 400 m. Different soil, climate and viticultural technique interactions, result in great variability with respect to morphological, ampelographical and physiological characters of Xinomavro as well as in the characteristics of the wines produced. 

Foliar application of urea has proven to be an effective method for increasing the amino acid content in grapes, especially when the vineyard has additional nitrogen needs. These treatments can prevent problems of stucking fermentation during winemaking.