C5 - The Growing Environment Flashcards
What is the one factor influencing a plant’s growth that does not vary?
CO2
How is a region’s climate defined?
The annual pattern of temperature, sunlight and rainfall averaged out over several years
How is weather defined?
The annual variation that happens relative to the climatic average
Below what temperature is it too cold for a vine’s cells to function?
10 degrees C
What happens to a vine above 22 degrees?
The vine’s cell start to consume more sugar than the vine can produce
In order to ripen grapes successfully, the vine needs the average temperature to be between…
16 and 21 degrees C
What determines which vines will thrive within a certain region?
Temperature
What has an impact on each stage of a vine’s cycle?
Temperature
What occurs later in a cooler region?
Bud burst
…and…can be disrupted in a cooler temperature, doing what to yields?
Flowering and fruitset.
Reducing yields.
If temperature is cool during ripening, what happens to acidity and sugar levels?
Acid falls less and less sugar is accumulated
What may happen to black grapes in cool growing conditions?
They will produce wines which are overly astringent and herbaceous (a result of being physiologically unripe)
Why can white grapes cope with cooler conditions better?
They have no need for ripe tannins and wines are balanced with higher acidity levels
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
List the factors affecting annual temperature…
Latitude
Altitude
Ocean currents
Fog
Soil
Aspect
How does latitude affect a vine’s temperature needs?
The further from the equator, the cooler an area is on average.
What approximate latitudes are best for viticulture? Why?
30 - 50 degrees. These latitudes satisfy a vine’s need for warmth, but also winter dormancy.
How does temperature drop with altitude?
0.6 degrees C with every 100m increase in altitude
How do ocean currents affect climate/weather?
By cooling or warming the air above and around them
How does fog affect temperature? List two examples of areas where this is an important factor…
It cools an area.
California and Casablanca in Chile.
What kind of soil absorbs and reradiates the sun’s heat?
Darker soils or those with a higher stone and rock content
How does soil with a high water content affect ripening?
It delays it, as it takes more energy to heat the soil and heat from the vines is conducted away more quickly
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.
How is continentality defined?
It is the temperature difference between winter and summer
What is the main factor affecting continentality? Why?
Proximity of large bodies of water.
They cool down and heat up slower than land masses.
Name the four main inputs required for a vine
Heat
Sunlight
Water
Nutrients
What gives a vine heat?
Sunlight and soil
Where does a vine get light from?
The sun and the soil
How does a vine get water?
Rainfall, irrigation and water stored in soil/bedrock
Where does a vine get its nutrients?
Soil deposits
Bedrock
Humus
Fertiliser
What’s the biggest factor that can influence diurnal range?
Seas and lakes
What can affect levels of cloud cover?
Smaller bodies of water
What two positive effects do cool nights have on a vineyard?
They help the vines rest, extending the growing season They help slow the loss of volatile aromas
What effect do warm nights have on a vineyard?
They help to accelerate ripening, particularly the production of sugar
What kind of wines do regions with a high diurnal range generally create?
Fresher and more aromatic
What is the impact on wine of a smaller diurnal range?
They are usually fuller bodied
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
What is Winter Freeze?
When the temp drops below -20 deg C. This can damage or kill a vine
The part of a vine most at risk during winter freeze is…
The graft callus
How can graft calluses be protected during winter freeze?
By covering up the callus with soil (sometimes the whole vine)
What is Spring frost?
Cold air below 0 deg C collecting at ground level and freezing any settled water vapour
What happens to a vine during spring frosts?
Newly burst buds or shoots are killed by frost
What are the four main methods of protection against frost?
Burners
Wind machines
Sprinklers
Vineyard design
What are burners/smudge pots?
The heat they generate creates movement in the air, preventing cold air from settling and causing frost. Smudge pots also generate smoke, insulating heat from the vineyard
Why/how do sprinklers work in frost protection?
When their water freezes, it releases latent heat, protecting buds and shoots
How can thoughtful vineyard design help to protect against frost?
By planting crops away from depressions, you will avoid the worst of potential frosts. Vines can also be trained high.
What impact can a mild winter have on a vine?
It 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 its quality
How else can mild winters be bad for viticulture?
Larger populations of pests can survive to attack the vines in the following summer
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
What limits the RATE of photosynthesis?
Light levels
The more…the greater the amount of glucose the leaves produce for growth and grapes
Light
Name an area where sugar levels will remain low due to cloud cover
Hunter Valley, Australia
What can happen to grapes if it is too sunny?
They can become sunburnt, resulting in bitter dark patches on grapes
Name the three factors affecting sunlight…
Seas and Lakes
Latitude
Aspect
Explain how proximity to large bodies of water can affect sunlight…
Vineyards near seas and lakes tend to experience more cloud cover. Sometimes vineyards situated above rivers and lakes can benefit from reflected sunlight.
Explain the effect of latitude on sunlight. Give two places which benefit from this effect…
Day length during the summer season is longer, the further away from the equator a vineyard is.
Germany (Riesling) and Washington State (Cabernet)
Which elements of aspect are favourable for the ripening of grapes?
Steeper slopes and facing toward the equator
Where in the world is sun exposure most important and why?
Furthest away from the equator as the sun’s energy is weaker here
What is a grapevine’s natural habitat?
Woodland, where they would flower and fruit when they broke through the canopy
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
Under what light conditions are buds less fruitful?
In shade
Besides total lack of ripening, what else may occur in shaded conditions?
Coulure
What is used to ensure the ripening of grapes in areas with less light exposure?
Canopy management techniques
What can the effect of exceptionally cloudy conditions be on wine?
Low levels of alcohol, unripe tannins and flavours
How can poor light conditions affect crops?
Crops may reduce
Name the three uses a vine has for water…
It gives rigidity to shoots and leaves
Regulates its temperature
Swells its grapes
What is transpiration?
How a vine accesses water through its roots and draws it up to its leaves
What determines the amount of water a vine uses?
Temperature
Why is water stress beneficial to grape ripening?
The vine has enough water to photosynthesise, but switches its glucose resources from shoot growth to grape ripening
Viticulturally speaking, how can the impact of shading be reduced?
By water-stressing the vine
What can be disrupted by rainfall?
Flowering and fruit set
What encourages fungal infection?
Damp conditions after rainfall
What is the potential impact of heavy rain shortly before harvest? How does this impact resulting wines?
Berries can swell, diluting flavours in the wines they produce
In extreme cases after rainfall, berries can split. What other hazard does this attract?
Fungal disease
What can be used if rainfall is insufficient?
Irrigation
What are the three main irrigation techniques?
Drip irrigation
Sprinklers
Flood irrigation
What is 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.
What are the benefits and disadvantages of sprinklers as a form of irrigation?
They are a lot cheaper than drip irrigation, but they waste a lot of water and create damp conditions like rainfall, increasing disease-risk
What is the benefit of flood irrigation? What are the barriers? Give two examples of where it can be/is used…
It’s very cheap, but only possible in flat or gently sloping vineyards where there is access to large quantities of water.
Chile and Argentina.
What can happen during short term drought?
The vine can temporarily stop transpiration, preserving its resources
What happens if the vine has access to too much water during the growing season?
It promotes excessive vegetative growth
What effect does it have on grapes if a vine becomes vegetatively overactive?
This diverts sugars from the ripening grapes. Also the excess of shoots and leaves increases the risk of shading.
What effect can summer hail have on a vine?
It can damage the grapes and even the vine itself, in worst cases, destroying an entire crop
Name an area particularly prone to hail…
Mendoza, Argentina
List three preventative measures against hail…
Netting, aircrafts and rockets
When is the growing season in the northern/Southern Hemisphere?
April - October and October - April
In order, what are the temperature definitions laid out by WSET for ‘Cool’, ‘Moderate’, ‘Warm’ and ‘Hot’
Cool: 16.5 c or below
Moderate: 16.5c to 18.5c
Warm: 18.5c to 21c
Hot: Above 21c
List continentality, rainfall, temperature of growing season and sunlight of growing season for all three climate types…
Continental: High continentality, low rainfall, cool, moderate, warm or hot temp and usually very sunny
Maritime: Low to medium continentality, medium to high rainfall, cool or moderate temperature and cloudy
Mediterranean: Low to medium continentality (precipitation mostly in winter), moderate or warm temperatures and usually sunny
When typically does the temperature rapidly drop in a continental climate?
Autumn
What kind of varieties are best suited to cool continental climates?
Ones that bud late and ripen early
What climates experience very dry summers?
Continental
When does it rain the most in a maritime climate?
It rains evenly throughout the year
What effect does the year-round rain in a maritime climate have on other climatic features?
It moderates sunlight and temperature
How does a maritime climate affect the length of a growing season?
It lengthens it as a result of its moderating effects
Name the biggest hazards of a maritime climate
Spring and summer rains, which can be a very significant risk to the flowering, fruit set and health of the grapes at harvest
What is Humus?
Organic matter
What are the three major components of soil?
Soil particles, stones and rocks
Humus
Plant nutrients
Where do soil particles, stones and rocks come from?
The underlying rock or later deposits laid on top of it
What are the largest types of soil particle?
Sand
What are the smallest soil particles?
Clay
From a viticultural point of view, what are the disadvantages of large soil particles?
They are poor at holding water and plant nutrients
What kind of particle size makes up the best soils?
A mixture of sizes
What are the benefits of Humus?
It is rich in plant nutrients and had excellent water retaining properties
What are the three key plant nutrients?
Nitrogen, Phosphorus and Potassium
Where do plant nutrients come from?
Decaying plant material
Manure
Dissolved mineral salts
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
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
How is water stored in the soil?
By binding with clay particles or humus. It may be accessible in the underlying rock, too.
What will happen to a vine exposed to too-high levels of nutrients?
It will grow too vigorously
What is the most common symptom linked to nutrient deficiency?
Chlorosis
What is Chlorosis?
The leaves turning yellow because they lose chlorophyll. Photosynthesis reduces and grape quality/yield is affected.
What’s the most common cause of Chlorosis? What sort of soil is most likely to cause this?
The inability of a vine to gain sufficient iron from the soil. Soils with high limestone content.
Give examples of places with soils high in limestone
Barolo, Burgundy, Rioja and Champagne
