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
Why are very hot summer temperatures bad for vines?
-Slows (and potentially stops) vine activity, preventing grapes from ripening properly
What 3 factors affect sunlight and how?
- Latitude (further from equator = more sun, summer day length is longer)
- Seas/Lakes (closer to seas/lakes = less sun)
- Aspect (facing equator = more sun)
When is lack of sunlight most harmful?
- Flowering and fruit set
2. Grape ripening
What is the effect of too much sunlight?
Sunburn, bittering grape skin flavors
How does a vine access water?
Though its roots
What is transpiration?
Process in which water is drawn up from the roots to the leaves
Why is it beneficial to limit the water supply one a sufficient canopy of leaves forms?
Vine has enough water for photosynthesis but the shortage of water means the vine focuses on ripening rather than further shoot growth
What can rainfall be supplemented with, if local laws permit?
Irrigation
What are the 3 irrigation techniques?
- Drip irrigation (most advanced, expensive): each vine has its own dripper, computer controlled to ensure that each vines gets optimum amount of water
- Sprinklers: waste water, can create damp conditions increasing risk of disease
- Flood irrigation (cheap): must be flatter vineyard
What are the effects of drought on a vine?
photosynthesis stops, leaves wilt, grapes fail to ripen, weakens vines, can kill vines
What are the effects of too much water on a vine?
- Vine continues to grow shoots and leaves during ripening seasons, more shade/canopy = less sugar for grapes
- Waterlogging: Root saturation and death
- Flowering and fruit set can be disrupted, reducing number of grapes formed
- Damp conditions foster spread of fungal diseases
- Excessive grape swelling that dilutes flavors
What is water logging and how can it be prevented?
When there is too much rain/water so the roots become saturated and die
Avoided by:
-Planting vines on slope
-Flat sites with drainage pipes installed
Why is hail bad for grape-growing? How can one protect against hail?
-Damange grapes and/or vine
-Netting (costly)
Example: Mendoza Argentina
What is climate?
A region’s annual pattern of temperature, sunlight, and rainfall over several years.
- Does not change from one year to the next
- Can change over decades
What is weather? Name a region with varying weather. Name a region with predictable weather.
A region’s annual variation that happens relative to the climactic average.
Varying: Bordeaux, France
Predictable: Central Valley, Chile
What is the growing season of the Northern Hemisphere? Southern Hemisphere?
Northern: April to October
Southern: October to April
What is the average growing season temperature of cool climate regions?
16.5 degrees C and below
What is the average growing season temperature of moderate climate regions?
16.5 to 18.5 degrees C
What is the average growing season temperature of warm climate regions?
18.5 to 21 degrees C
What is the average growing season temperature of hot climate regions?
21 degrees C and over
What is a continental climate? Which types of varietals are best suited for this climate? Name 2 regions with this climate.
- High Continentality: greatest difference in temperature between the hottest and coldest months
- Short summers
- Large, rapid temperature drop in fall
- Drier summer
- Risk of spring frost
Bud late, ripen early
Examples:
Chablis, Champagne
What is a maritime climate? Which types of varietals are best suited for this climate? Name 1 region with this climate.
- Cool to moderate temperatures
- Low Continentality
- Evenly spread rainfall to moderate temperatures
- Warm enough to continue to ripen in late fall
- Rain can be harmful to flowering, fruit set
Long, slow ripening
Examples:
Bordeaux
What is a mediterranean climate? What are the wines like from these regions? Name 4 regions with this climate.
- Low Continentality
- Warm, dry summers
- Risk of drought
-Fuller bodied, riper tannins, higher alcohol, lower acidity
Examples: Mediterranean, coastal California, South Africa, South Eastern Australia
Name the 2 purposes of soil.
- water
2. nutrients
What is the most crucial part of soil?
The size of the soil particles
What is the largest of the soil particles? The smallest?
Sand
Clay
What is humus?
Made up of decomposing plant and animal materials that are rich in plant nutrients and have excellent water retaining properties
When does the soil most need water? When does it need less water?
Most: early in season for shoot and leaf growth
Less: After veraison to promote ripening
How is water stored in soil?
Binds to clay particles or humus
What results from too much clay in soil?
Waterlogging
What results from too much sand or stones in soil?
Too much drainage, irrigation may be necessary
What is loam? Why is it ideal?
Mixture of sand and clay
- good drainage
- retain enough water for vine growth
What are the 3 most important nutrients for a vine.
- Nitrogen
- Phosphorus
- Potassium
What happens when soil is too nutrient-rich?
Vigorous growth forms thick canopy that shades too much
When happens when soil lacks nutrients?
Chlorosis: leaves turn yellow and photosynthesis is restricted, grapes struggle to ripen, quality and quantity of grapes reduced
