Use of multispectral satellite for monitoring vine water status in mediterranean areas

We analyze the effects of climate (temperature and pluviometry) on the phenologic stages of the vine (débourrement, flowering, ripening and grape harvest). We rebuilt time series starting from the beginning of the XIXth century for the Medoc and the area of Bordeaux, data very seldom mobilized by researchers.

Climate change will require the adaptation of agricultural systems and among the different means of adaptation, changing plant material is a promising strategy. In viticulture, different levels of diversity are currently exploited: clonal and varietal diversity for rootstocks and scions. A huge quantity of research aims to evaluate different genotypes in different environmental conditions to identify which ones are the best adapted and the most tolerant to future environmental conditions.

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. 

Global warming is responsible for a lack of organic acid in grape berries, leading to wines with higher pH and lower titrable acidity. The chemical, microbiological and organoleptic equilibriums are impacted by this change of organic acid concentration. It is common practice to acidify the wine in order to prevent these imbalances that can lead to wine defects and early spoilage. Tartaric acid (TA) is most commonly used by winemaker for wine acidification purposes. Fumaric acid (FA), which is authorized by the OIV in its member states for the inhibition of malolactic fermentation, could also be used as a potential acidification candidate since it has a better acidifying power than tartaric acid.

The two most deadly viruses infecting and threatening the productivity of grapevines worldwide are leafroll and red blotch viruses. There is no cure for viral diseases other than roguing the symptomatic vines and replacing them with certified vines derived from clean, virus-tested stocks.
Given that phloem plays a central role in virus infection, this study aimed to purge the virus by girdling the phloem of leafroll-infected vines at different phenological stages of infected grapevines. Phloem-girdling was performed on canes at veraison to varying regions between the proximal and distal clusters.