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