5. The Growing Environment Flashcards
What 5 things does a vine need to grow?
- Heat
- Sunlight
- Water
- Nutrients
- Carbon dioxide
Describe the 6 steps in the annual growth cycle of a vine.
- Budburst (spring): new shoots begin to grow
- Flowering & Fruit Set (late spring, early summer): vine flowers and small grapes form
- Grapes grow (summer): hard in texture, green in color, high acidity, no sugar
- Grapes ripen (late summer, early fall): swollen with water, sugar levels rise, acid levels drop, flavors develop, grapes change color
- Harvested (fall)
- Dormancy (late fall through early spring): vine drops its leaves
What is veraison?
The change of the color of grapes as then ripen (from green to blue/black, pink, or golden).
How does a vine carry out photosynthesis? Why is that important?
- Vine uses sunlight to combine CO2 and water to produce glucose and oxygen.
- Vine combines glucose and nutrients from the soil to support its growth and ripen its grapes.
Below what temperature is it too cold for vines to grow?
10 degrees C
What are the 6 factors that affect the heat of a vine?
- Latitude
- Altitude
- Ocean currents
- Fog
- Soil
- Aspect
Most vineyards lie between which latitudes? Why?
Between 30 degrees and 50 degrees under and over the equator.
-Closer to equator is hotter, farther is colder
What effect does altitude have on temperature?
As altitude increases, temperature drops.
Example: Cafayete (northern Argentina) is close to equator but high altitude
What effect do ocean currents have on temperature?
Depends on whether or not the currents are transporting warm or cold water.
Example: Humboldt Current off Chile and Benguela Current off out Africa are cooling;
Gulf Stream warms north-west Europe
What role does fog play in temperature?
Fog can help cool an area that may otherwise struggle
Example: California, Casablanca Valley (Chile)
What role does soil play in temperature?
- Soils that are dark in color or have a high stone and rock content absorb and reradiate more of the sun’s heat - critical for ripening fruit in cool climates.
- Soils with high water content require more energy to warm up, conduct heat from the vine more quickly than dry soils - can delay budburst.
What is aspect? What role does it play in temperature?
Aspect is the direction in which a slope faces.
Aspect facing equator = most heat:
-Northern Hemisphere: south facing slopes
-Southern Hemisphere: north facing slopes
-The steeper the slope, the more the effect (e.g. Mosel)
What is continentality? What effect does it have on grape-growing?
The temperature different between the coldest and hottest month
-A region’s continentality will determine the length of the growing season and thus the total amount of heat available to a vine; determines which varieties can grow there.
What effect does proximity to water have on continentality?
-Areas close to large bodies of water generally have a low continentality (warming effect in winter, cooling effect in summer)
What is diurnal range? What effect does it have on grape-growing?
The difference between daytime and night-time temperatures.
-Larger diurnal range regions can produce wines that are fresher and more aromatic
What’s the difference between cool night and warm nights?
- Cool nights help slow the loss of aromas and acidity in the grapes during ripening
- Warm nights accelerate ripening
What are the factors of diurnal range?
- Proximity to seas and lakes (closer proximity = smaller diurnal range)
- Level of cloud cover (cloudier = smaller diurnal range)
What is ‘earthing up’?
When earth is used to cover up and protect the raft from winter freeze
Under what temperature are vines at risk for serious damage or death? What part of the vine is most at risk?
-20 degrees C
The graft
What are the downsides of mild winters (or no winters)?
- Vine may produce multiple crops per year resulting in lower quality grapes and a shorter lifespan of the vine
- Larger populations of insect pests survive for the following summer
What is a spring frost?
When cold air below 0 degrees C collects at ground level, freezing any water vapor that has settled on the ground of the vine
-Can kill newly burst buds or young shoots
What are the 4 forms of protection from spring frost?
- Heaters: placed throughout the vineyard, lit if frost is forecast. Creates movement in the air preventing frost.
- Wind machines: large fan that draws warm air from above to keep the temp at ground level above freezing.
- Sprinklers: sprays water onto the vine to protect buds and shoots
- Thoughtful vineyard design: slopes, avoid depressions, training vines high
Why are cold spring temperatures bad for vines?
- Delays budburst, shortens growing season (might never get ripe enough)
- Disrupted flowering and fruit set, resulting in smaller than average crop
