5 - The Growing Environment Flashcards
The vine needs
Heat, sunlight, water, nutrients, carbon dioxide
Véraison
The first sign of the ripening. The grapes changes colour
Photosynthesis
Uses sunlight
6 CO2 + 6 H2O —> C6H12O6 (glucose) + 6 O2
Sugar and nutrients is used in the vine to
supports its growth and ripen grapes
Temp too cold for the wine to grow
<10C
During the winter
Vines are dormant
the defining factor that determines which grape varieties can be grown where
the amount of heat during the growing season
Factors affecting heat (6)
- Latitude: 30-50
- Altitude
- Ocean currents
- Fog
- Soil
- Aspect
Eks Altitude
Cafayate - northern Argentina
Eks Ocean currents
The Humboldt Current - Chile
The Benguela Current - South Africa
The Gulf Stream - north-west of Europe
Eks Fog
California
Casablanca Valley, Chile
How does soil affect heat?
Dark or high stone/rock content - absorb and reradiate heat
Soils with high water content require more energy to warm up, and conduct heat from the vine more quickly than dry soils —> can delay budburst
what is aspect?
the direction in which a slope faces
Eks Aspect
Mosel, Germany
Continentality
The temperature difference between the coldest and the hottest months
Effects of large bodies of water on continentality
Heat up and cool down more slowly than landmasses
—> warming effect on the surrounding air in winter
—> cooling effect in summer
Areas close to lbow: low continentality
How will the continentality influence what grape varieties can be successfully grown in an area?
A region’s continentality will determine the length of the growing season and this has an impict on the total amount of heat available to a vine.
Diurnal range
The difference between daytime and night-time temperatures
Cool nights vs warm
Cool: Help slow the loss of aromas and acidity in the grapes during ripening
Warm: Accelerate ripening
Effect from water on diurnal range
Reduce diurnal range.
Keep adjacent vineyards warm overnight and provide cooling breezes during the day.
Effect from cloud cover on diurnal range
+ Where and why
Reduce diurnal range
Generally greater cloud cover nearer seas and lakes
Temperatures drop more quickly on clear nights without clouds
Rise more slowly on cloudy days, when sunlight cannot heat the ground directly
Temperature hazards
- Winter:
Below -20 can damage/kill vines
Mild winter: no dormant period - Spring frost can kill newly burst buds and young shoots
- The growing season
Cold temp: delay budburst, shorten growing season, flowering & fruit set can be disrupted
Warm temp: vine activity will slow down and stop (prolonged, extreme heat)
winter freeze
temperature below -20C
‘earthing up’
earth can be used to cover up and protect the graft
Mild winter and no dormant period (4)
- May produce more than one crop each year
- Life will be shortened
- Quality of the grapes will suffer
- Larger populations of pests survive
What is spring frost
Cold air below 0C collects at ground level, freezing any water vapour that has settled on the ground or the vine
Protection against spring frost (4)
- Heaters: creates movement in the air
- Wind machines
- Sprinklers
- Thoughtful vineyard design: slopes, avoid depressions, vines trained high
Temperatures during the growing season
Cold:
1. may delay budburst in the spring. Shortens the growing season and may not be enough time to ripen grapes fully.
2. disrupt flowering and fruit set. Smaller crop of grapes
Warm
3. prolonged periods of extreme heat: vine activity will slow and eventually stop. Prevents grape ripening. In extreme cases the vine will die.
Factors affecting sunlight (3)
- Latitude: day length
- Seas and lakes: more cloud cover, reflection from surface
- Aspect
Sunlight hazards
Low: flowering, fruit set, photosynthesis, ripening etc
High: sunburn (bitter flavours developing in the grape skins)
how to tackle sunlight hazards
Canopy management:
1. maximise sunlight in very cloudy areas
2. enough shade in extremely sunny regions
the vine needs water for …
- photosynthesis
- to swell its grapes during ripening
Transpiration
Water is drawn up from the roots to the leaves
Irrigation (3)
- Drip irrigation
- Sprinklers
- Flood irrigation
Water hazards
- Drought
- Too much water
- Hail
drought
If there is a water shortage the vine can temporarily stop transpiration in order to preserve its resources.
Prolonged: Water stress: photosynthesis stops, leaves wilt and grapes fail to ripen. Ultimately this can weaken and kill a vine.
too much water
- Continue to grow shoots and leaves during the ripening season, leaving less sugar for ripening grapes.
- Increase the amount of shading in the canopy, restricts grape ripening.
- Waterlogged soil can cause the roots to become saturated and die.
- Flowering and fruit set can be disrupted by heavy rainfall
- Damp conditions encourage spread of fungal diseases
- Shortly before harvest: berries swell excessively. Dilutes flavours and may split (fungal dis.)
how to tackle too much water
- planting vines on a slope
- installing drainage pipes to aid the flow of water away from the roots
how to tackle hail
- netting
- several vineyard sites in different locations
Climate
The annual pattern of temperature, sunlight and rainfall averaged out over several years.
Does not change from one year to the next.
Can alter over a period of decades.
Weather
The annual variation that happens relative to the climatic average.
Some regions experience greater variation in this pattern than others: Bx in Fr vs Central Valley in California
Growing season
Northern Hemisphere: April-October
Southern Hemisphere: October-April
Cool climates
Regions with an average growing season temperature of 16,5C or below
Moderate climates
Regions with an average growing season temperature of 16,5C to 18,5C
Warm climates
Regions with an average growing season temperature of 18,5C to 21C
Hot climates
Regions with an average growing season temperature in excess of 21C
Which grapes can be successfully ripened in any given region
- climate
- continentality
- diurnal range
- level and timing of rainfall and sunlight
Continental climate
- Highest continentality
- Short, dry summers
- Large, rapid temp.drop in autumn
-
Cool cont.: risk from spring frost, low temp. during growing season can affect flowering, fruit set and ripening.
Better suited to var. that bud late and ripen early. - high temp.: irrigation can be necessary
Ex: Champagne, Chablis
Maritime climate
- Cool-moderate temperatures
- Low continentality
- Rainfall tends to be evenly spread throughout the year –> helps moderate temp. –> Temp. are warm enough for grapes to continue ripening far into the autumn
- Rainfall in the spring and summer can be harmful to the flowering, fruit set and health of the grapes at harvest
Ex: Bx
Mediterranean climate
- Low continentality
- Summers tend to be warm and dry
- Extra warmth & sunlight: fuller bodied, riper tannins, higher alcohol, lower acidity
- Lower rainfall: pos. effect on health of the grapes, can lead to drought
ex: Mediterranean, coastal California, Chile, South Africa, South Eastern Australia
soil
- Above the underlying bedrock
- Made up of: tiny particles of various sizes, larger stones or rocks and humus (organic matter)
Stones, sand and clay
- Come from the underlying rock or later deposits laid on top of the rock.
- The size of the soil particles is crucial (stones>sand>clay)
humus
made up of decomposing plant and animal materials that are rich in plant nutrients and have excellent water retaining properties
how is water stored in the soil?
by binding to clay particles or humus
ideal water for a vine
a good supply of water early in the season to support strong shoot and leaf growth, followed by mild water stress after véraison (promote grape ripening)
loam
- mixture of sand and clay particles
- good drainage
- retain enough water for vine growth
nutrients
nitrogen, phosphorus, potassium
a common symptom linked to a lack of nutrients
chlorosis
chlorosis
The leaves turn yellow and the vine’s ability to photosynthesise is restricted. Grapes struggle to ripen properly and their quality and quantity is reduced.
how to solve chlorosis
using an appropriate fertiliser
