1- Where do Grapes grow ?: Temperature, Lighting and precipitation.
Vine vines have very specific climatic requirements in terms of temperature, lighting and rainfall.
It is true that many varieties are resistant to drought, others to winter frosts and others require few hours of light for their correct maturation.
2- Thermal needs of the Vineyard
Obviously the temperature depends, among other factors, on the continentality or proximity to the sea, on the altitude and on the altimetry.
At the world level, the vine , except for specific varieties and peculiar areas, can be cultivated between the parallels 50ºN and 40ºS .
We will remember that approximately from these latitudes each degree that this latitude increases the temperature drops approximately 0.6ºC.
The same happens with altimetry and that from a certain elevation the increase of 100 meters supposes a decrease of approximately 0.5ºC.
The effects of latitude and altitude are modified by the regulatory role exercised by the proximity of large bodies of water , as occurs in the proximity of the sea and in that of the great lakes, both in Europe and America, but also, the own River beds act as a regulating effect on temperature , which allows the presence of great and wonderful vineyards in the surroundings of these bodies of water.
In Spain, two examples are, the two banks of the Great Duero rivers and the Ebro, where two of the best national wine-growing areas are found, the Rioja and the Ribera del Duero.
3- Limits for the cultivation of the vine.
The technically reasonable limits for the cultivation of the vine range from sea level to about 780 m of altitude, although there are higher vineyards even reaching 1,200m.
As a plant, the vine has an optimal term between 9 and 18ºC , although these limits depend on varieties, patterns and specific conditions of the environment that can modify the limits tolerated by the strains.
The thermal limit that allows the proper ripening of the grape is not easy to determine, but temperatures must exceed at least 18ºC from the time it is aged.
Average heat requirements for viticultural varieties are around 2,900 to 3,100ºC (Sum of average monthly temperatures for one year).
The limits that produce frosts in the vines are not easily determined since the effects of cold on the inflorescences are evident from -0.3ºC, while the vineyard vegetation can endure without obvious symptoms up to -2.5ºC without suffering strong frosts.
There are varieties that are very sensitive in sprouting and the effects of cold manifest them at 0.2ºC and frost at -0.1ºC.
In any case, the sensitivity to winter frosts has clearer effects, since the damage to buds begins at -12ºC while the wood supports well up to -16ºC / -18ºC.
The sudden temperature changes are more harmful than downs progressive and excess production plants and agostamiento problems are much more sensitive to the excesses of the winter cold.
Remember that there are specific varieties that can withstand even lower temperatures.
4- Lighting. Lighting needs of the vineyard.
The light needs of the vine are very high, being a long-day plant whose basic requirements range between 1,200 to 1,800 hours.
The effects of the slope and the color of the soil greatly influence the lighting of the bunches and the hours of heat they receive.
The slopes facing south and east have better illumination as it happens if the slopes are greater.
5- Rainfall. Minimum necessary for the cultivation of the vine.
Although the vine is a plant that supports drought very well , especially if it is progressive, it needs between 500 and 600 mm of water per year to cover its needs .
This rainfall is difficult to achieve in many vine growing areas in the eastern and southern peninsula, where the vines produce thanks to soil management techniques even with less than 330 mm per year.
The distribution of rainfall in the vegetative cycle is as important or more important than the total rainfall in the area.
High rainfall and more or less permanent humidity or flooding in the seedlings “trigger” attacks by fungi such as mildew and botrytis, constituting important problems in the cultivation of the vineyard.
The adaptability of the vines to unfavorable weather conditions is very high and today the vine has a wide worldwide distribution from tropical and subtropical areas, through semi-desert areas or even in danger of desertification and reaching cold areas.
The thermal changes day / night are very important to a good evolution of the wine cycle and the production of aromatic wines, fruity and fine.
There are varieties well adapted to local conditions that can seem extreme for cultivation, such as Monastrell in certain very dry soils and very harsh climates.
It is necessary to know the demands of the vine, in terms of climatic conditions, but by managing these environmental conditions, maximizing lighting and adapting water availability and thermal values, the quality of the harvest can be greatly improved and excellent wines can even be obtained outside. of the conditions considered “a priori” as suitable for cultivation and
You can expand and deepen information in any of these viticulture articles published in this blog: