The Growing Environment Flashcards
What does a vine need in regards to temperatures ?
If the temperature drops below 10 degrees it is too cold for the vines cells to function, This is why vines are dormant in winter. Excess temperatures of 22 degrees, above this the vines cells start to consume more sugar than photosynthesis can produce, activity will slow and stop.
In order to ripen grapes succesfully what does the average temperature need to be ?
between about 16 degrees and 21 degrees
Temperature has an impact on each stage of the vines growth cycle. What happens in cooler regions ?
In cooler regions, budburst occurs later, this shortened growing season could mean the grapes fail to ripen fully.
Temperature has an impact on each stage of the vines growth cycle. What happens in warmer regions ?
Warmer conditions lead to earlier budburst, a potentially longer growing season, accelerated ripening, accelerated loss of acidity, ripening of tannins and development of flavours.
Factors affecting the Annual Temperature:
Latitude
To meet the vines temperature needs and its preference for a dormant period, most vineyards lie between the latitudes of 30’ and 50’ north and south of the Equator.
Factors affecting the Annual Temperature:
Altitude
The mean annual temperature drops by about 0.6c with every 100 meter increase in altitude. This means that regions that might otherwise be to hot can make an area suitable to cultivate
Factors affecting the Annual Temperature:
Ocean Currents
The major currents transport large volumes of warm or cool water across the surface of the planet, leading to local warming or cooling.
Factors affecting the Annual Temperature:
Fog
Fog can help cool an area that may otherwise struggle to produce high quality grapes, this is particularly important feature in areas in California and Casablanca in Chile.
Factors affecting the Annual Temperature:
Soil
Soils that are either dark in colour or that have a high stone and rock content absorb and re-radiate more of the suns heat than lightly coloured soils. This can be critical in cool climates.
Soils with high water content need more energy to warm up, this can delay bud burst.
Factors affecting the Annual Temperature:
Aspect
The direction in which a slope faces is known as its aspect. Vineyards facing the equator receive the most heat. The Northern Hemisphere south facing slopes get the most warmth, whereas in The Southern Hemisphere it is the north facing slopes.
Factors affecting Continentality
What is Continentality
The temperature difference between winter and summer is referred to as continentality, The main factor that can reduce the extent of the variation between seasons is the proximity of large bodies of water. Sea or Large Lakes.
Factors affecting Continentality
How does it effect the growing environment
Large bodies of water heat up and cool down slower than landmasses. Therefore in the winter they have a warming effect and in the summer they have a cooling effect on the surrounding air.
Factors affecting Diurnal Range
How do smaller bodies of water effect the Diurnal Range
As well as moderating seasonal temperatures, seas and lakes are the biggest factor that can reduce the temperature difference between day and night (The Diurnal Range). Relatively small bodies of water, smaller rivers and lakes, can hold enough warmth to keep the vineyard warm overnight and provide cooling breezes during the day.
Factors affecting Diurnal Range
How do Cloud cover effect the Diurnal Range
The level of cloud cover influences because temperatures drop more quickly on clear nights , when there is no insulating cloud blanket, and rise more slowly on cloudy days when sunlight cannot directly penetrate the ground.
Factors affecting Diurnal Range
How does it effect the grapes/wine ?
Cool nights help the vine rest and extend the growing season. They also help slow the loss of volatile aromas during ripening.
Warm nights accelerate ripening, particularly the production of sugar.
