The Growing Environment Flashcards
What are the five things a vine need ?
Heat
- sun
- reflected from soil
Sunlight
- sun,
- reflected from water
Carbon dioxide (CO2)
- atmosphere
-
Water
- rainfall
- irrigation
- water stored in soil
Nutrients
- soil particules
- humus
- fertiliser
- vines uses sunlight to combien water and carbon dioxide to produce glucose and odygen, process known as photosynthesis
The variations of these factors influence all aspects of annual growth, and affect quality and quantity of fruits.
What is the minimum temperature for a vine to grow ?
10°
Why heat is important for the vine ?
to grow, to successfuly flower, set and ripe.
The amount of heat in the growing season is the defining factor that determines which grape varieties can be grown where
What are the factors affecting heat ?
- Latitude (regional)
- Altitude (regional
- Ocean Currents, and large lakes (regional and site)
- Fog (site)
- Soil (site)
- Aspect (site)
- Continentality (regional)
- Diurnal range (regional)
What are the temperature hazards ?
- Winter
- Spring frosts
Exc
Explain Latitude and its influence on heat
Most vineyards are situated between latitudes of 30° and 50° North and South of the Equator
Closer to Equator is to hot and closer to the poles, too cold.
Other factors thant latitude can make are outside these limits suitable
Explain altitude and its influence on heat
- As altitude increases , temperature drop
- Regions at high altitude are colder and are suitable for different type of vines
- You could grow vine closer to the equator with altitude
Explain ocean currents and their effects on heat
Major ocean currents transport large volumes or warm or cold water at the surface, leading to localised warming or cooling effect
Ex: Benguela Current of South Africa cool the region, and Gulf Stream warms north-west europe, which would be to hot or cold for grapegrowing otherwise
Explain Fog and its effect on heat
Fog can help cool area that may otherwise struggle to porude high-quality grape
ex. Someareas in California, Casablanca valley in chili
Explain soil and its effect on heat
Soils dark in colour or high stone and rock content absorb and reradiate more of the sun’s heat than lighter coloured soils.
This reradiated warmth can be critical for ripening fruit in cool climates.
Soils with high water content require more energy to warm and can delay budburst
Explain Aspect and its influence on heat
Aspect is the direction in which a slope faces
The vineyards with an aspect facing equator receive the most heat
- North Hemisphere - facing south
- South Hemisphere - facing north
Steeper slopes benefit more from thi effect
Particularly important in cool climate region when extra warmth can make the difference in ripening. Ex. Mosel, Germany
Explain Continentality and its effect on heat
- Continentality in the temperature difference between the coldest and hottest months
- Determines the lenght of the growing season, the total amount of heat available to the vine. This in turn influence the choice of grape varieties
high continentality = large difference
low continentality = less variation
Region close to **large body of water **are often moderated by the water warming and cooling effect, leading to low continentality.
Region far inland see more extremes and have a** high continentality**
Explain Diurnal range and its effect on heat
- Difference between daytime and night-time temperatures
- Cool nights help slow the loss of aromas and acidiity during ripening
- Warm nights accelarte ripening
ex: In hot climate, a large diurnal range can produce fresher and more aromatic wine
What can influence the diurnal range ?
Diurnal range is affected by :
- Moderating effect of the seas and lakes (reduction of the diurnal range)
- Level of could cover, generally near seas and lake.
- On clear nights, the temperature drop more quickly without insulating blanket of clouds (increasing range)
- On cloudy day, the temperature rise slowly when sunlight cannot heat the ground (reducing range)
Explain the influence of winter on grapegrowing
- Vines can be damaged or even killed from winter freeze
- The part the most at risk is the graft
- ## If the winter is mild or not present, the vine will not have a dormant period and may produce more than one crop each year. Its life will be shortened and the quality will suffer. The pests will also survive.
At which temperature a vine can be seriously damaged in the winter?
-20°
What is the process for protecting the graft during winter frosts?
Earthing up
Earth is used to cover up and protect the graft
Explain the influence of spring frosts on grapegrowing
- Occurs when cold air below 0° collects at ground level and freeze water vapour that as settled of the ground or vine.
- Can kill newly burst buds or young shoots
- The damage on yields can be enormous
What are the four main forms of protection again spring frosts ?
- Heaters
- Wind Machines
- Sprinklers
- Thoughtful vineyard design
Explain how heater protects from spring frosts
- Places throughout vinyeards if frost is forecast.
- Heat they generate creates movement in the air preventing cold air from settling and causing frost
Explain how wind machines protect from spring frosts
- Look like a large fan that draws warm air from above to keep the temperature at gount level above freezing
- Some wind machines incorporate heaters.
Explain how sprinklers protect from spring frosts
-Sprinklers spray water onto the vines.
- As the water freezes, it releases some heat into the plant tissus protecting the buds and shoots
Explain how thoughtful vineyard design protects from spring frosts
Minimise the risk of frosts
- plant vineyards on slopes to avoid depressions in which cold air can collect
- vineyards planted on the middle of the slopes are noticeably less at risk from frost damage than lower areas
- Vines are trained high to avoid the worst of cold air
Explain how the temperature of the growing season has an effect on grapegrowing
Cold temperature
- In the spring, can delay budburst
- Shortens the growing season and may have an impact on ripeness
- Flowering and fruit set is disrupted by cold resulting smaller crop
Very hot temperature
- For a prolonged period of extreme heat, vine will slow and stop, even with sufficient water. Prevent grapes to ripen properly.
- hot and dry conditions increase the risk of fire. Vineyards can be damaged, or smoke, during ripening, cangive smoky or plastic-like aromas to the wine.
- There are techniques to minimise impact of smoke-tainted fruit, but impossible to eliminate completely
Why sunlight is important for the vine ?
- The more ligth there is, the more a vine will photosynthesise and the greater the amount of glucose produced for growth and ripening grapes.
- Flowering and fruist set also benefit greatly from plenty of sunlight
- Do not need constant bright sunshine but intense cloudy or foggy conditions lead to reduction and photosynthesis