The Growing Environment Flashcards
What are the essential elements that a vine needs from its environment? Why?
Sunlight, water, and CO2 - for photosynthesis. Plus small amounts of nutrients
How does photosynthesis work?
Sunlight gives energy which enables chlorophyll in the leaves to combine water and CO2 to create sucrose. Sucrose is transformed to fructose and glucose in the vine
Why is glucose important?
Vine building block. Glucose molecules combine to make larger carbohydrates like cellulose (builds roots, trunk, shoots, leaves, fruit). Also is the base for tannins, acidity, flavor molecules.
Below what temperature is the vine dormant?
10 degrees C
At what temperatures is a vine working?
Above 10 C and below 25 degrees C when its metabolism increases and it needs more sugars. (Warmer climate = needs more sun, water, CO2)
When does vine growth peak?
22-25C. Metabolic needs increase faster than ability to photosynthesize sugar. Significantly slows growth at 30
What is climate?
The annual weather pattern of an area over several decades
What is a cool temperature climate?
Av mean temp during growing season (April-Oct or Oct-April) of below 16C
What is the temp of a moderate climate? Examples?
Av mean temp 16.5 to 18.5C
Bordeaux, Rioja, Piedmont, N Rhône
What is the temp of a warm climate?
Av mean temp = 18.5-21
Douro, S Rhône
What is the temp of a hot region?
Over 21C
Jerez, central Cali
What is continentality
The difference between the average mean temperature in hottest and coldest month. Large =continental, small =maritime
What characterizes a maritime climate?
Low annual temp range (warm summer mild winter) and high rainfall, much during growing season. Long growing season with moderate temps. Often near large water. Usually more cloud cover. Bordeaux, Rias Baixas
What characterizes a Mediterranean climate
Low annual temperature range but rain falls mostly during the winter. Usually dry and sunny during growing season. Fuller bodied wines generally.
What characterizes a continental climate
Wide annual temperature range. Short growing season usually, but temps could get very hot. Less sunlight during autumn. Tend to be drier. Could be cool or warm region.
What characterizes a tropical climate
Minimal temp variation. Vines have no time to rest. Not great for wine.
Mesoclimate v macro climate v microclimate
Macro = regional Meso = site Micro = canopy (row or single vine)
What is aspect?
The direction a vineyard slope faces. Affects sunlight exposure
How does slope affect sunlight intensity
Sunlight intensity reduces as the slope increases. The available sunlight is divided out over a larger area of land.
In what aspect direction does a slope get the most sunlight?
The one that faces the sun during most of the day (south facing in the northern hemisphere and north facing in the south). Towards the equator!
What direction do many of the best vineyard sites face and why?
East facing. The suns rays are more direct/scattered less in the morning because the earth cooled overnight and the dust is settled. West facing have scattered sun and damper cooler conditions
Besides sunlight, why are sloping vineyards good?
Air movement: cold air settles at the bottom which makes a warm thermal layer mid slope. Air movement deters frost and helps ripening
Soils tend to be poorer, coarse, well drained
Why van slopes be bad?
Erosion
Higher costs
Are isolated hills good or bad? Why?
Good! No big currents of cold air from bigger hills
Why are bodies of water good in cooler climate? Why are they bad?
Good: Reflect rays Store heat Source of water Reduce frost risk Mists for noble rot Bad: Humidity = fungal diseases
Advantages/disadvantages of forests
Good:
Windbreaks
Store heat
Reduce erosion
Bad
Cool mesoclimate in warm weather
Increase humidity
Birds
What does a thick canopy do in a cool climate?
Retain acid (cool grapes)
reduce flowering and berry set
Reduce sugar accumulation
Compete for energy
How does temperature affect yield and quality?
Yield:
Vine vigor
Number of flower clusters and size
Fruit set success
Quality:
Yield
Accumulation of sugar and reduction to acidity
Development of aromas
What temperatures will injure vines?
Freeze begins at -15, is serious at -20, and is fatal at -25
If the temp falls below -20 once every 20 years no good for wines. Mean temp for coldest month should be above -1
What is the most commonly used heat summation system?
Amerine and Winkler (1944)
How is heat summation calculated?
Measure mean temperature for the month, subtract 10, and multiple by the number of days in the month. Total these numbers for the growing season months to get growing degree days.
What is Category I?
Below 1370 GDD (Chablis, Mosel)
What is Cat II
1370 - 1650 (Napa, BDX)
CatIII?
1650-1930 (Barossa, Stlenbosch)
CatIV?
Fortified
CatV?
Bulk and drying grapes
What limits the heat summation system?
It only relates to temperature. Variability, sunlight, and humidity do not necessarily correlate to heat.
What is Smart and Dry?
A climactic index used in Australia that uses the mean temperature of the warmest month and corrects for contknentality, day length, rainfall, etc
How does the EU classify climate?
Zones A through C according to climate with legislation for each (deacidification and chapitalisation). Minimum potential alcohol, level of must enrichment, and acid adjustments all change.
Zone A regions and legislation
Germany except Baden and UK
Min natural alcohol: 8%
Max enrichment: 3% (4.5% in really bad years)
Max total alcohol from enrichment: 11.5% (12% reds)
Acid: -1 to 0 g/L
Zone B regions legislation (natural alcohol/max enrichment/total alcohol from enrichment/acid adjustment tartaric)
Baden, Loire, Champagne, Alsace, Austria 8% 2% 12%, 12.5 reds -1 to 0gL
Zone CI regions legislation (natural alcohol/max enrichment/total alcohol from enrichment/acid adjustment tartaric)
BDX, SW France, Rhône, Spain, Hungary, Trentino-Alto Adige 9% 1.5% 12.5% -1 to 2.5
Zone CII regions legislation (natural alcohol/max enrichment/total alcohol from enrichment/acid adjustment tartaric)
Languedoc, Provence, Northern Spain (not Atlantic) Italy 9 1.5 13 -1 to 2.5
Zone CIIIa regions legislation (natural alcohol/max enrichment/total alcohol from enrichment/acid adjustment tartaric)
Bulgaria and Greece 9 1.5 13.5 -1 to 2.5
Zone CIIIb regions legislation (natural alcohol/max enrichment/total alcohol from enrichment/acid adjustment tartaric)
Portugal Southern Spain Calabria Puglia, parts of Greece, islands 9 1.5 13.5 0 to 2.5
Why does a vine need water?
Photosynthesis
Access nutrients from soil
Ensure vine growth and yield and fruit
Prevent cells from collapsing
What happens with too much water stress?
Halts vegetative growth and loses leaves
How much water does a vine need in general?
Cooler: 500mm/yr
Warmer: 750mm/yr
What affects the amount of water a vine needs?
Vine density (1mm rainfall on 1 sq meter = 1 liter of rain) - lower density=more rain for the vine
Soil water retention capacity
When the rain falls
What does excess rain do?
Cool mesoclimate Difficult for machinery Increase fungal disease Reduce fruit set Bunch compaction and Berry splitting Dilute must during harvest
When is rainfall the worst?
Autumn (harvest). Winter doesn’t affect growth much unless it is stored. Moderate in spring can grow shoots. Summer can be good but watch out for diseases.
How can a vintner in a cooler climate compensate for slower photosynthesis?
Increase the leaf area
Why remove leaves before harvest?
Ensure full ripening without risk of sunburn. Also can reduce pyrazines
How does day length affect the vine?
It doesn’t affect the developmental stages but it does affect capacity for photosynthesis (higher latitude = longer days in summer)
How does sunshine intensity affect yield and quality?
Heat accumulation, bud viability and maturation/initiation of flowers, Berries, cane, and rate of photosynthesis
How does sunlight relate to sugar in grapes?
Amount of photosynthesis balanced with grape’s other metabolic needs. Hot and cloudy could equal low potential sugar. Cool and sunny could equal high sugar
How much sunshine does Vitis vinifera need to produce ripe fruit?
1250 hours
Pollution decreases available sunshine up to 10%!
How do ocean currents affect climate?
Cooling currents - Pacific and Humboldt off of Chile, mists and fogs
Gulf Stream warms UK
How much does annual temperature decrease according to elevation?
Mean annual temperature decreases by .8C with every 100m rise.
How do mountains affect regions?
Protect from wind and rain
Altitude increases cooling winds
What does soil compaction do?
Poor rain infiltration (pooling and erosion)
Poor soil structure (drainage, aeration, root penetration
What micronutrients are present in soil?
Boron, manganese, copper, iron, molybdenum, zinc, cobalt, chlorine, silicon
What are the major nutrients in soil?
Nitrogen: very important for plant growth. Component of chlorophyll, amino acids, nucleic acids. Stimulates photosynthesis and drives biochemical reactions
Phosphorus: key to energy fixation, encourages root growth and ripening
Potassium: regulates flow of water and sugar in plant (ripening)
Calcium: regulates cell acidity and cell walls
Sulfur: essential part of amino acids and enzymes
Magnesium: essential component of chlorophyll (regulates acidity and sugar metabolism, ripening)
What element is present in fertile soils? What effect does this have?
Nitrogen
Encourages vigorous shoot growth and puts demands on sugars produced by photosynthesis aka less sugar for grape
What planting density and soil type makes the best wine?
Densely planted small vines in infertile soils
How to manage high soil fertility
Lower planting density and bigger vines which spreads out the nutrients
What does the pH scale measure
The concentration of hydrogen ions in soil solution
What are the values for acidic soil?
PH 4-6.9
What are the values for basic soil?
7.1 to 8.5
What is the lowest soil pH tolerable by vines
5 bc below this aluminum becomes available and poisons the plant
What effect does pH have on nutrient availability?
Higher pH can inhibit uptake of iron and micronutrients increasing chlorosis
