Level 4 D1 Chap 3 - The Growing Environment

Question 1

Question

Answer 1

Answer

Question 2

What are the effects of latitudes at or above 50°C and what factors (natural and vineyard mgmt choices) can alleviate some concerns?

Answer 2

Concerns:

• Less solar radiation (less sunlight and lower temps) because
• • solar radiation must travel through more atmosphere
• • solar radiation hits earth at a lower angle and thus, is more diffused.

Management choices:

• Plant vines at a lower altitude for warmth
• Plant vines with aspect towards the sun to maximise sun exposure.
• Use early ripening grapes - e.g. Chardonnay and Pinot Noir

Natural mitigating factors:

• Proximity to water can dampen temperature swings, protecting from frost in winter, e.g. finger lakes
• Free draining soils warm up more quickly and promote early budburst to maximise the growing season

Question 3

What are the effects of latitudes at or below 30°C and what factors (natural and vineyard mgmt choices) can alleviate some concerns?

Answer 3

Concerns:

• More solar radiation per year
• More intense solar radiation
• • less atmopshere
• • not at an angle, so less diffused

Plant at high altitude, and/or on a slope facing away from the sun (e.g. south facing in southern hemisphere).

Each 100m of altitude, drops average temperate by 0.6°C

Proximity to water can dampen temperature swings - limiting overheating in summer

Use late ripening grapes in warmer climates (e.g. Cabernet Sauvignon)

Clay rich soils hold water and delay budburst as they remain cool

Question 4

What is the minimum annual rainfall for a vine?

Give examples of how soil type can increase/decrease these minimums in Hawkes Bay and Jerez respectively

Answer 4

500mm in cool climates,
750mm in warm

Hawkes Bay has to irrigate despite receiving 1000mm due to highly drained soil.

Jerez copes on 650mm due to albariza, a clay soil with excellent water retention and that forms crust that reduces evaporation.

Question 5

Which wine growing areas are particularly reliant on irrigation?

Answer 5

Argentina, California, South Africa and Australia

Question 6

What are optimum rain levels at key points during the season for grape development?

Answer 6

High rain in early spring to encourage early vegetative growth

Reduced water in late spring and early summer to allow germination and fruit set, and limit competition between grapes and leaves for nutrients

Limited rainfall in late ripening to stop dilution and splitting

Question 7

What are the top 5 vine nutrients and their purpose?

Answer 7

1. Nitrogen - needed for vine growth, vine vigor & grape quality
2. Potassium - vine growth and regulates water flow in vine
3. Phosphorus - used in photosynthesis
4. Calcium - used in cell structure and photosynthesis.
5. Magnesium - in chlorophyll; important for photosynthesis

Question 8

What is the impact of too much / little nitrogen?

Answer 8

High levels result in too much vigor

• sugars are diverted from growing grapes to growing vines and shoots
• encourages fungal disease.
• all the secondary impacts of shade

Low levels:

• reduced vigor
• yellowing of leaves
• yeast may be impacted during fermentation.

Question 9

What is the impact of too much / little potassium?

Answer 9

High levels - can impact magnesium uptake, reducing yields. It may raise also raise the pH in the grape/must as potassium accumulates

Low levels impact sugar accumulation and limit growth

Question 10

What is the impact of too much / little phosphorus?

Answer 10

High levels are not common

Low levels detrimentally impact root systems, impacting water and nutrient uptake.

Question 11

_____ is the yellowing of vines in high pH soils (e.g. ____ or ____ soils) that limit uptake of ______

Answer 11

CHLOROSIS is the yellowing of vines in high pH soils (e.g. CHALKY or LIMESTONE soils) that limit uptake of IRON.

This is common in CHALKY soil.

Question 12

What are the minerals particle types that can make up soil?

Answer 12

Sand (large), silt (medium), clay (fine)

Question 13

_____ describes a soil with moderate proportions of _____, ______ and ______

Answer 13

LOAM describes a soil with moderate proportions of SAND, SILT and CLAY

Question 14

What does GDD stand for? How is it determined? (Also known as Winkler index.)

Answer 14

Growing degree days

Average temperature in excess of 10°C in a given month x # of days in month

Calculated for each month in a season

Add those numbers up.

Divided into five regions.

Question 15

Name at least three climate classifications

Answer 15

• Growing Degree Days (GDD)
• Huglin index (widely used in Europe)
• Mean temperature of warmest month (MJT - used in hot climates where the stress of the warmest month (Jan or July) is important)
• Growing Season Temperature (GST)
• Koppen’s classification (maritime, Mediterranean, continental)

Question 16

What GST bands are used by WSET to categorise climates?

Answer 16

Cool: <16.5°C
Moderate: 16.5°C - 18.5°C
Warm: 18.5°C - 21°C
Hot: >21°C

Question 17

What are the negative implications of climate change on vines and ultimately wine?

Answer 17

Careful - very area specific!
Warmer temps…so vine cycle is faster
- Budburst is earlier & each stage is faster
- Higher sugar levels increase alcohol
- Acid reduction is faster
- This increases pH (problematic in winemaking)
- And increased water stress

BUT

• Aroma and tannin compound development do NOT quicken
• Specific flavour profiles may change (e.g. black pepper in Syrah may not develop)

Erratic weather events can reduce yields (e.g. storms, hail)

Question 18

What are the positive implications of climate change on vines and ultimately wine?

Answer 18

Careful - very area specific!

• Opens up new areas for cultivation
• Reduced impact of fungal diseases

Question 19

What are the effects of sunlight on the chemistry of the vine and grapes?

Answer 19

• Photosynthesis - 1/3 direct sunlight needed.
• Successful fruit set
• Anthocyanins - develop with sunlight.
• Methoxypyrazines - reduced with sunlight.
• Tannins: Pre-veraison, sunlight increases tannins;
• • Post-veraison, sunlight promotes polymerisation, which decreases bitterness.
• Aroma compounds / precursors - favorables ones, e.g., terpenes - increase with sunlight.
• Warms grapes which increases respiration and decreases malic acid
• Compound buds – increases bud fruitfulness next year

Question 20

What are other geological and topographic factors that impact temperature and sunlight?

Answer 20

• Latitude
• Altitude
• Slope and aspect
• Proximity to water
• Winds
• Soil
• Mist, fog and clouds

Question 21

What are the different reasons vines need water?

Answer 21

• Turgidity
• Photosynthesis
• Regulating its temperature
• Solvent for nutrients in soil
• Medium for all biochemical / physiological mechanisms in vine

Question 22

What happens when a vine experiences water stress?

Answer 22

• Stomata close to preserve water
• No CO2 coming in
• No photosynthesis
• No sugar and therefore, no energy
• No vine growth or ripening

Extreme? Leaf loss and vine death

Question 23

When is some water stress good?

Answer 23

Before veraison – inhibits further vegetative growth.

If too much water at this time, vegetative growth is promoted & prolonged, creating competition for the vine’s sugars. This can delay or compromise ripening.

Question 24

What’s wrong with having too many shoots and leaves?

Answer 24

Too much shade which leads to:

• reduced formation of anthocyanins
• less tannin polymerisation
• higher levels of methoxypyrazine
• decreased development of favorable aroma compounds
• increased risk of fungal disease

Question 25

What is the evapotranspiration rate and what does it depend upon?

Answer 25

The rate at which water is no longer available to the vine because it has been transpired from the vine or has evaporated from the soil.

Depends on

• temperature
• humidity
• wind