C5 - The Growing Environment (reviewed) Flashcards
What can happen to grapes if it is too sunny?
They can become sunburnt, resulting in bitter dark patches on grapes
How should water supply to a vine ideally vary over the growing season?
A good supply early on to support growth, then water stress after veraison to benefit ripening
What is the biological benefit of a grapevine only bearing fruit once it has broken woodland canopy?
Here its fruits would be more visible to animals, ready for propagation
Name the three factors affecting sunlight…
- Seas and Lakes - Vineyards near seas/lakes experience more cloud cover. Sometimes vineyards situated above rivers and lakes can benefit from reflected sunlight.
- Latitude - Day length during the summer season is longer, the further away from the equator a vineyard is. e.g., Germany (Riesling) and Washington State (Cabernet)
- Aspect - Steeper slopes and facing toward the equator increase sunlight
When is the growing season in the Northern/Southern Hemisphere?
- Northern: April - October
- Southern: October - April
List the factors affecting annual temperature…
- Latitude - The further from the equator, the cooler an area is on average. 30 - 50º latitudes satisfy a vine’s need for warmth, but also winter dormancy.
- Altitude - temperature drop 0.6ºC every 100m increase in altitude
- Ocean currents - cool or warm the air above and around them
- Fog - It cools an area. e.g., California and Casablanca in Chile.
- Soil -
- Darker soils or those with a higher stone and rock content absorbs and reradiates the sun’s heat
- High water content soild delay ripening, as it takes more energy to heat the soil and heat from the vines is conducted away more quickly
- Aspect - can affect ripening - the side of a slope facing towards the equator receives more sunlight and heat. e.g., Mosel Valley
Name a rare region with a low continentality, but high diurnal range. Why?
Napa Valley. It’s close to the Pacific, moderating continentality, but experiences on-shore and off-shore breezes and fogs, increasing diurnal range
Name an area where sugar levels will remain low due to cloud cover
Hunter Valley, Australia
What impact can a mild winter have on a vine?
- Can prevent the vine from being dormant, and in the worst cases the vine can produce more than one crop a year, shortening the vine’s life and reducing quality
- It can also allow for larger populations of pests can survive to attack the vines in the following summer
What is the one factor influencing a plant’s growth that does not vary?
CO2
What is a grapevine’s natural habitat?
Woodland, where they would flower and fruit when they broke through the canopy
What effect can summer hail have on a vine? how can growers protect their vines?
- It can damage the grapes and even the vine itself, in worst cases, destroying an entire crop
- Mendoza, Argentina - particularly prone to hail
- Protective measures: netting, aircrafts and rockets
Describe Winter Freeze
- When the temp drops below -20 deg C. This can damage or kill a vine
- The graft callus is the most vunerable part, can be protected by covering up the callus with soil (sometimes the whole vine)
What can be used if rainfall is insufficient? How?
Irrigation
Drip irrigation -
- The most advanced and expensive form of irrigation.
- Each vine has its own dripper that can be computer controlled, ensuring that each vine gets an optimal amount of water.
Sprinklers -
- Cheaper than drip irrigation, but waste a lot of water and create damp conditions like rainfall, increasing disease-risk
Flood irrigation
- Very cheap but only possible in flat or gently sloping vineyards where there is access to large quantities of water (e.g., Chile and Argentina)
In order, what are the temperature definitions laid out by WSET for ‘Cool’, ‘Moderate’, ‘Warm’ and ‘Hot’
Based on average temperature during growing season:
- Cool: 16.5ºc or below
- Moderate: 16.5ºc to 18.5ºc
- Warm: 18.5ºc to 21ºc
- Hot: Above 21ºc
What limits the rate of photosynthesis?
Light levels - the more light, the greater the amount of glucose the leaves produce for growth and grapes
How is water stored in the soil?
By binding with clay particles or humus. It may be accessible in the underlying rock, too.
Describe impact of cooler temperature on vine growth
- Bud burst: happens later
- Flowering and fruitset: can be disrupted leading to lower yields
- During ripening: acid falls less and less sugar is accumulated
-
Shoot and leaf growth:
- Back varieties: will produce wines which are overly astringent and herbaceous (a result of being physiologically unripe)
- White: cope with cooler conditions better because they have no need for ripe tannins and wines are balanced with higher acidity levels
What negative effect can rainfall have?
- Disrupt flowering and fruit set
- Damp conditions after rainfall encourage fungal infection
- Before harvest, berries can swell, diluting flavours in the wines they produce and in extreme cases, berries can split, atracting fungal diseases
What kind of wines do regions with a high vs small diurnal range generally create?
- High diurnal range: Fresher and more aromatic
- Small diurnal range: usually fuller bodied
Describe the vine needs for water…
It helps the vine do the following
- Gives rigidity to shoots and leaves
- Regulates its temperature
- Swells its grapes
Temperature determine amount of water a vine uses
Under water stress conditions, the vine has enough water to photosynthesise, but switches its glucose resources from shoot growth to grape ripening
Water-stressing the vine can also reduce the impact of shading
What can happen during short term drought and where there is too much water during the growing season?
- Short term drought: The vine can temporarily stop transpiration, preserving its resources
-
Too much water: the vines promotes excessive vegetative growth
- This diverts sugars away from the ripening grapes
- The excess of shoots and leaves increases the risk of shading.
Describe the importance of temperatures in wine growing
- Amount of heat in the growing season is the defining factor that determines which grapes can he grown in a given region
- Temperature has an impact on each stage of a vine’s cycle
- Average temperature: between 16ºC and 21ºC degrees C will allow grapes to full
- Above 22ºC degrees - The vine’s cell start to consume more sugar than the vine can produce
- Below 10ºC - too cold for a vine’s cells to function
How is a region’s climate vs. weather defined?
Climate
The annual pattern of temperature, sunlight and rainfall averaged out over several years
Weather
The annual variation that happens relative to the climatic average
Describe diurnal range.
- Definition: difference between day and night time temperature
- Cool nights help slow down loss of aromas and acidity during ripening, while warm nights accelerate ripening
- In war/hot climates, high diurnal range can help produce fresher wines
-
Factors reducing diurnal range:
- Biggest factor - Seas and lakes (even small ones) - keep warn at night and cooler during the day
- Secondary factors: cloud cover - act as insulating blanket - reduce temperature drop at night and increase during the day
List in order the key stages of a vine’s growth cycle…
- Budburst
- Early shoot and leaf growth
- Flowering and fruit set
- Véraison/berry ripening
- Harvest
- Winter dormancy
What is transpiration?
How a vine accesses water through its roots and draws it up to its leaves
Where in the world is sun exposure most important and why?
Furthest away from the equator as the sun’s energy is weaker here
List continentality, rainfall, temperature of growing season and sunlight of growing season for all three climate types…
Continental:
- Contientality: High
- Rainfall: Low
- Temperature: Cool to Hot (dry summers, temp. drops rapidly in Autumn)
- Sunlight: usually very sunny
- Suited for variteies that bud late and ripen early
Maritime:
- Contientality: Low to medium
- Rainfall: Medium to high - evenly throughout the year, moderates sunlight and temperature - lengthens growing season
- Temperature: cool or moderate
- Sunlight: cloudy
- Hazards: Spring and summer rains - can be a very significant risk to the flowering, fruit set and health of the grapes at harvest
Mediterranean:
- Low to medium continentality
- Rainfall - precipitation mostly in winter
- Temperature: moderate or warm
- Sunlight: usually sunny
Describe Spring frost.
Cold air below 0 deg C collecting at ground level and freezing any settled water vapour killing newly burst buds or shoots
Protection methods against spring frost:
- Burners - heat they generate creates air movement, preventing cold air from settling and causing frost. Smudge pots also generate smoke, insulating heat from the vineyard
- Wind machines - large fan, draw air from above to keep air temperature at ground level above freezing
- Sprinklers - when water freezes on the burst, it releases latent heat, protecting buds and shoots
- Vineyard design - planting crops away from depressions, you will avoid the worst of potential frosts. Vines can also be trained high.
How does aspect affect ripening? Give an example of a region which benefits particularly from a good aspect…
The side of a slope facing towards the equator receives more sunlight and heat.
The Mosel Valley.
What is the most common symptom linked to nutrient deficiency?
Chlorosis -
- The leaves turning yellow because they lose chlorophyll. Photosynthesis reduces and grape quality/yield is affected.
- Caused by the inability of a vine to gain sufficient iron from the soil.
- Soils with high limestone (Barolo, Burgundy, Rioja and Champagne) content are prone to Chlorosis
What will happen to a vine exposed to too-high levels of nutrients?
It will grow too vigorously
Name the main inputs required for a vine to grow
- CO2
- Heat - from sunlight and soil
- Sunlight - from sun and the soil
- Water - from rainfall, irrigation and water stored in soil/bedrock
- Nutrients - Soil deposits, Bedrock, Humus, Fertiliser
Discuss soil composition
3 types - Soils particules, Humus, nutrients:
-
Soil particles, stones and rocks - come from the underlying rock or later deposits laid on top of it
- Smallest: Clay
- Largest: Sand
- Large particules: poor at holding water and nutrients
- Best soils are made of a mixture of sized marticules
- Humus - Organic matter rich in nutrients and excellent water retaining properties
- Plant nutrients
- Mainly: Nitrogen, Phosphorus and Potassium
- Comes from Decaying plant material, Manure, Dissolved mineral salts
Ideal soil has relatively few nutrients and is well drained, but able to store enough water to support the vine through the growing season
Describe the ideal soil for viticulture
It has relatively few nutrients and is well drained, but able to store enough water to support the vine through the growing season
What negative effects can high summer temperatures have on a vine? What if there’s insufficient water too?
- They accelerate ripening, altering the grapes’ compositions and changing the styles of the wine.
- When water is low, the vine may stop ripening its grapes, it may shed its leaves and even die
How is continentality defined?
It is the temperature difference between winter and summer.
Main factor affecting continentality are
- Proximity of large bodies of water.
- They cool down and heat up slower than land masses.
What effects do cool / warm nights have on a vineyard?
Cool nights:
- They help the vines rest, extending the growing season
- They help slow the loss of volatile aromas
Warm nights:
- Help to accelerate ripening, particularly the production of sugar
What happens if there is too much shade?
Impact:
- Buds less fruitful
- Coulure
- Crops may reduce
- Low levels of alcohol
- Unripe tannins and flavours
Canopy management techniques can help the ripening of grapes in areas with less light exposure
