Term for the period during the growth cycle in which there is no or very little rainfall (Rain) there. For the assessment of the negative impact on viticulture are the complex relationships of soil water supply, air temperature and humidity significant. This also depends on the area and the prevailing there climate from. In normally cool and humid winegrowing areas, drought or dryness can be especially harmful in the production of red wine also be advantageous if resulting from the resulting lower growth, so to speak a natural, quality-enhancing yield restriction results.
In extreme cases, however, this leads to Rebstock to the water stress (Drought stress), which is especially true at the time of maturation (Maturity) disadvantageous earnings and quality of the wine (in Europe these are normally the months of August to September). In conjunction with high daytime temperatures above 40 ° C, it also happens heat stress, In hot and dry regions with too little precipitation, an artificial one is used irrigation, This is common in southern countries or overseas such as Australia or South America. Within the EU, such measures are usually the exception or subject to authorization.
In the course of their development, certain plants have adapted to the environment and developed various defense mechanisms against drought and dryness (see below) xerophilous ). Some grape varieties have a pronounced resistance against drought and get along with relatively little water. That's among other things Airén (Spain), Argaman (Israel), Arinto (Portugal), Bobal. Cayetana Blanca (Spain), Garnacha Tinta Grenache Noir (Spain, South of France), Lairén (Spain), Viura or Macabeo or (Spain, France), Savatiano (Greece), Touriga Franca. Touriga Nacional and Trincadeira Preta (Portugal). In the new breed Of grape varieties, dry resistance plays an important role, which is also achieved by "hardening". By the climate Change Such properties are becoming increasingly important. See also below climate and Weather,