3. The Growing Environment Flashcards
What’s a mediterranean climate?
- Low annual differences between summer and winter temperatures
- Annual rainfall happens in winter months, with dry summers
- Ex. Napa Valley + Coonawarra
What is continentality?
A measure of the difference between the annual mean temperatures of the hottest and coldest months (usually inland = more continental)
How do winds affect grapes?
Reduce stagnant air, influence temperature, increase evapotranspiration rates
How does altitude affect grapes?
- Temperature falls ~0.6 degrees C every 100m increase
- Many of the best vineyard sites in high latitude areas (Burgundy, Loire) are at low altitudes
- Sunshine and UV radiation are greater at higher altitudes
- High altitude sites have high diurnal range
What is the definition of weather?
The annual variation that happens relative to the climatic change
What is albariza?
A clay soil that has good water retention and releases water slowly to the vines – also forms a crust when dry, reducing evaporation (famous in Jerez, Spain)
What are the temperature ranges for cool, moderate, warm and hot climates?
- Cool: 16.5 or less
- Moderate: 16.5-18.5
- Warm: 18.5-21
- Hot: 21+
What is an evapotranspiration rate?
The amount of transpiration from the vine combined with the evaporation of water from soil surface (high ET rate means that more water is required to meet vine’s requirements)
What is the definition of climate?
The annual pattern of temperature, sunlight, rainfall, humidity & wind averaged out over several years (30)
What is soil made up of?
Geological sediment, organic remains (humus) and pores in between that contain water & air
How does latitude affect grapes?
Grapes grown at lower latitudes have higher levels of sugar, lower levels of avid, riper aromas and higher (but riper) tannins with more colour intensity
What are some climate classifications? (5)
- Growing Degree Days
- The Huglin Index
- Mean Temperature of the Warmest Month
- Growing Season Temperature
- Koppen’s Classification
What is humus?
Organic matter in the soil formed by decomposition of plant material by microbes & earthworms
What’s a continental climate?
- More extreme differences between summer and winter temperatures
- Short summers, cold winters
- Ex. Burgundy + Alsace
How do characteristics of the soil affect the grapes?
- Soils that drain freely warm up more quickly than damp soils
- Light coloured soils reflect some energy from solar radiation
- Dark coloured soil (and stony soils) absorb more energy and re-radiate it when temperatures are cooler
How do slopes/aspects affect grapes?
- Slopes facing east benefit from morning sunshine that can heat up atmosphere (extends ripening hours, dries out canopy)
- Slopes facing west may be too hot in afternoon (can be alleviated in areas with coastal breezes)
What are some effects sunshine has on the vines/grapes?
- Enhances anthocyanin (black colour pigment)
- Reduces methoxypyrazines
- Increases favourable aroma precursors/compounds
- Warms grapes, therefore increases rate at which magic acid is used up in respiration
- Can cause sunburn (hazard!)
How does proximity to water affect grapes?
- Water heats up and cools down slower than dry land
- During the day, water and air above a body of water remain cool and lowers temperature of local area
- Air above dry land heats up more quickly and this warm air rises
- Cool air from above water is drawn to land to replace the warm air as it rises, resulting in cool, humid afternoon breezes
- Opposite happens at night
What is loam?
A soil that has moderate proportions of sand, silt & clay
How do mist/fog/clouds affect grapes?
Can limit sunlight (therefore photosynthesis), lower temperatures, and cause fungal diseases
What temperatures does photosynthesis occur? What about fruit set?
Photosynthesis - between 18-33 degrees C
Fruit set - between 26-32 degrees C
Are constant temperatures more favourable?
- In warm, hot climates, a large diurnal range is more favourable (cool period at night can slow respiration of magic acid and be beneficial in developing anthocyanin)
- In cool, moderate climates, a low diurnal range is more favourable so that night time temperatures still allow ripening to continue
How does climate change affect wine production?
- Rises in temperatures
- Changes in distribution of rainfall
- Greater weather variability and frequency of extreme events
What are the 5 main nutrients required for successful vines?
1) Nitrogen (needed for photosynthesis)
2) Potassium (helps control flow of water)
3) Phosphorus (photosynthesis)
4) Calcium (role in structure of plant cells)
5) Magnesium (photosynthesis)
What is ENSO?
- El Nino-Southern Oscillation
- A climatic cycle in the Pacific Ocean that has significant affect on weather patterns
What’s a maritime climate?
- Low annual differences between summer and winter temperatures
- Rainfall spread out throughout year
- Ex. Bordeaux
