D1 Viticulture: The Growing Environment Flashcards
Factors that influence the growing of wine grapes around the world. (83 cards)
1
Q
What temperature ensures vine dormancy?
A
Under 10°C / 50°F
2
Q
At what temperature do winter freeze and/or damage occur to a vine?
A
-20°C / -4°F
3
Q
Budburst is stimulated above this temperature.
What else stimulates budburst?
A
- 10°C (50°F);
- Warm soil temperatures can also stimulate budburst.
4
Q
What is the optimal temperature range for photosynthesis?
A
18–33°C (64–91°F)
5
Q
What is the minimum outdoor temperature a vine needs for the flowering and fruit set stage?
A
Minimum 17°C / 63°F
6
Q
What is the optimal temperature range for fruit set?
A
26–32°C / 79–90°F
7
Q
Warm temperatures (25°C / 77°F) around the time of fruit set promote increased bud fruitfulness for:
- that same year
- the next year
- the year after next year
A
The next year
8
Q
What do methoxypyrazines smell like?
A
Herbaceous / green bell pepper
9
Q
The breakdown of methoxypyrazines is hindered by:
- cool conditions
- warm conditions
- soil drainage
A
Cool conditions
10
Q
What conditions can cause photosynthesis to slow down or stop?
A
- Extreme heat, especially when combined with dry conditions;
- Water stress (the vine tries to protect itself by closing its stomata, reducing water vapor loss, but closed stomata can’t take in carbon dioxide which the vine needs for photosynthesis);
- Cold, cloudy conditions.
11
Q
Even though sunlight is needed for photosynthesis, sunlight doesn’t have to be 100% full, unhindered sunlight for photosynthesis to occur.
It’s only when light levels fall below ___ that sunlight becomes a limiting factor in photosynthesis.
A
1/3
12
Q
What are the benefits of having direct sunlight on grapes?
A
- Promotes development of anthocyanins;
- Reduces methoxypyrazines;
- Enhances accumulation of tannins pre-véraison;
- Enhances polymerization of tannins after véraison (decreasing bitterness);
- Increases levels of aroma precursors and aroma compounds;
- Increases metabolization rate of malic acid in grape respiration, leading to lower acidity levels.
13
Q
What are the natural factors that affect temperature and sunlight?
A
- Latitude;
- Altitude;
- Slopes and Aspect;
- Proximity to water;
- Wind;
- Soil characteristics;
- Mist, fog + clouds.
14
Q
Regions at lower latitudes (nearer the Equator) receive:
- less intense
- more intense
solar radiation than latitudes nearer the poles.
A
More intense
Solar radiation at the Equator is more powerful because the radiation travels through a smaller section of atmosphere and hits the Earth’s surface at a larger angle (nearer perpendicular).
15
Q
The number of hours of solar radiation in low latitude regions are similar daylight hours throughout all seasons of the year.
However, regions at high latitudes have ____ summer daylight hours and ____ winter daylight hours.
A
- Longer summer daylight hours;
- Shorter winter daylight hours.
Longer daylight hours during the summer benefits grapes grown at these cooler latitudes.
16
Q
Temperature falls by roughly ____ every 100 meter increase in altitude.
A
0.6°C (1.1°F)
This is why high-elevation sites are advantageous in areas of low latitude.
Conversely, high latitude areas that have relatively low elevation can make for sufficient ripening.
17
Q
Why do vineyards at high elevations generally have cooler nighttime temperatures than vineyards at low elevations?
A
The air is thinner at higher elevations, so it holds less moisture which means heat escapes quickly.
At lower elevations, the air in the atmosphere holds more moisture which absorbs some of the energy the soil radiates out (that it had accumulated during the day), so some heat is retained at night.
18
Q
What is aspect?
A
The direction a vineyard faces
19
Q
Why does the importance of aspect and slope steepness increase at high latitudes?
A
- Solar radiation hits the Earth at a low angle at high latitudes, so an aspect that faces the Equator optimizes heat and light;
- Slope increases the angle (nearer to perpendicular) at which solar radiation hits the Earth’s surface, thereby increasing intensity of heat and light.
Conversely, in warm regions a vineyard whose aspect faces away from the Equator limits the amount of heat and light which can help the grapes retain freshness and acidity.
20
Q
What are some benefits to planting on slopes?
A
- Shallow, poor soils;
- Good drainage;
- Provides shelter from bad weather;
- Provides frost protection.
21
Q
What are some cons to planting on slopes?
A
- Soil erosion;
- Difficult or impossible to use machinery.
22
Q
What are some benefits for east-facing slopes?
A
East-facing slopes see morning sun, which is gentler than afternoon sun, and heats up the atmosphere slowly. This means:
- Air and soil temperatures are at their lowest in the morning and they’re slow to heat up, which extends the hours of vine growth and ripening (an advantage for cool climates);
- Morning dew dries out earlier in east-facing vineyards, reducing the spread of fungal disease.
23
Q
Describe how areas near bodies of water are able to remain relatively cool.
A
In the daytime, the water and air above a body of water remain cool, which lowers the average temperature in the surrounding/nearby area.
Air directly above dry land heats up more quickly than air above water, and this warmer air rises. Cool air from above the water is sucked in towards the land replacing the warm air as it rises, resulting in cool, humid afternoon breezes.
24
Q
How does a body of water keep its surrounding area warmer at night?
A
Bodies of water release their warmth slowly (as opposed to land, which loses its warmth quickly without solar radiation), so at night the body of water is releasing the heat it acquired during the day.
25
How can ocean currents influence wine growing areas?
Warm ocean currents like the Gulf Stream can help buoy a cooler or marginal climate, such as Bordeaux;
Cool ocean currents like the California current can help cool down a region that sees high temperatures.
26
Sunlight reflected off of bodies of water is most advantageous for:
* cool climates
* warm climates
* vineyards at low latitude
Cool climates
27
What causes El Niño?
Warm water in the western Pacific Ocean that moves eastward along the Equator towards the Caribbean.
28
What are the effects of El Niño on the east side of the Pacific?
* High levels of rainfall and risk of hurricanes in South America and California due to a warmer eastern Pacific Ocean;
* Disrupted pollination and fruit set from higher rainfall;
* Increased vegetative growth (which can hinder ripening) due to excessive water availability;
* In Washington and Oregon, it brings warmer than average temperatures and drier conditions.
29
What are the effects of El Niño on the west side of the Pacific (read: in Australia)?
Warmer temperatures and drought conditions, which can cause extreme vine stress and even vine damage.
30
What causes La Niña?
A cooler-than-average eastern Pacific Ocean
31
What are the effects of La Niña on the east (United States) and west (Australia) sides of the Pacific?
* In Washington and Oregon, La Niña results in cooler, wetter conditions;
* In California and South America, it results in warmer, drier conditions;
* In Australia, it causes wetter and cooler conditions.
32
What factors do winds and breezes influence?
* They moderate temperature;
* Lower disease risk because they move humid air out from a vine's canopy;
* Increase evapotranspiration (which may lead to water stress);
* Strong winds can damage vines and trellising, which can lead to yield reduction and higher labor/equipment costs.
33
If you, as a grape grower, plant a row of trees near your vineyard to create a windbreak, what do you have to be mindful of?
Not to plant the trees so close to the vineyard that they compete with the vines for nutrients and water.
34
Why is it desirable for cool-climate vineyard areas to have free-draining soils?
* Free-draining soils warm up more quickly in the spring than damp soils;
* this encourages the breakdown of starch in the roots, which stimulates budburst and shoot growth;
* Warm soils also encourage root growth, which means the vine can absorb more water and nutrients.
35
Fog is a dense form of mist.
What are fog and mist made of, and how do they form?
They are made of **tiny drops of water hanging in the air just above ground level**.
Both form **when warmer water in the air is rapidly cooled**, causing it to change from invisible gas to tiny visible water droplets, like when warmer air over water suddenly encounters the cooler surface of land.
36
Vineyards that see a lot of mist or fog are at an increased risk of what?
* Reduced photosynthesis from limited solar radiation;
* Fungal disease.
## Footnote
(and if the vineyard sees dry, sunny afternoons following the morning mists, the vineyard can experience noble rot)
37
In cool climates, vines need a minimum of \_\_\_\_mm of rainfall per year.
In warm climates, vines need at least \_\_\_\_mm of rainfall per year.
Cool: 500mm
Warm: 750mm
38
What does a vine use water for (and need water for)?
* Turgidity (so that it doesn't wilt);
* Photosynthesis;
* Regulating its temperature;
* Water acts as a solvent for nutrients in the soil (so the vine can take up the nutrients through its roots);
* Water is used for all internal, vascular mechanisms of the vine.
39
Describe transpiration.
The process of **how water is absorbed by a vine's roots, transported through the plant, and then out of its leaves in vapor form**.
The warmer the climate, the faster water evaporates from the leaves, which means the vine needs more water from the soil.
40
What are stomata?
Stomata are pores on the underside of leaves that release water vapor out of the vine and allow carbon dioxide and oxygen to diffuse in and out of the leaves.
41
What are the risks if a vine's stomata partially or fully close?
* Photosynthesis slows or stops because no water vapor is being expelled and no gases are coming in;
* This can cause the vine’s growth to be stunted or ripening to slow down;
* Potential leaf loss;
* Death in extreme cases.
42
For the grapevine, why is plentiful water in the spring better than plentiful water in the summer?
In the spring, plentiful water encourages robust leaf growth and the establishment of a large, leafy canopy to support the growth of the vine and, later, the ripening of grapes.
In the summer, plentiful water encourages vegetative growth and prolongs or delays ripening (which discourages development of anthocyanins, tannins and aroma compounds, but promotes methoxypyrazines).
Too much water in summer can lead to a bushy, dense canopy which, in more humid areas, increases the risk of fungal disease due to poor ventilation.
Too much water in summer can also dilute sugars or cause grapes to split (promoting rot).
43
Air that is low in humidity can increase what in the vine and its grapes?
* Evapotranspiration;
* Grape transpiration, which leads to....
* Higher sugar accumulation in the grapes.
44
Name some Pros and Cons for a vineyard that is located near a large body of water.
Pros
* Diurnal + seasonal temperatures are moderated;
* Ocean currents can increase or decrease a region's average temperature;
* Breezes off the body of water increase air circulation, reducing likelihood of frost.
Cons
* Proximity increases humidity and therefore risk of fungal disease.
45
What is evapotranspiration rate?
The amount of transpiration from a vine plus the evaporation of water from land (soil surface) to the atmosphere.
46
Name three natural factors that affect water availability.
1. Rainfall;
2. Land + soil characteristics;
3. Evapotranspiration.
47
What does the evapotranspiration rate depend on?
1. Temperature;
2. Humidity;
3. Wind.
48
What weather conditions lead to higher evapotranspiration rates?
**Hot, dry, and windy** weather conditions
## Footnote
Vines in these conditions need more water, so irrigation may be a solution.
49
What are **the five most important nutrients** a vine needs?
1. **N**itrogen
2. **P**hosphorus
3. **P**otassium
4. **C**alcium
5. **M**agnesium
50
What are **six other nutrients** that play a role in vine growth and reproduction?
1. **B**oron
2. **C**opper
3. **I**ron
4. **M**anganese
5. **S**ulfur
6. **Z**inc
51
What is nitrogen important for?
Vegetative growth
* Too much nitrogen makes the vine grow too many leaves and shoots, taking energy away from the grapes;
* Too little nitrogen stunts vigor, and leaves can turn yellow.
52
What is potassium important for?
Flow of water in the vine and overall vine growth
* Too high potassium can reduce yields and lead to poor ripening and higher pH in the grapes;
* Too little potassium can lead to low sugar accumulation in the grapes, reduced yields, and poor vine growth generally.
53
What is phosphorus important for?
Photosynthesis
* too little in the soil negatively affects root development, reduces general vine growth, and can lead to lower yields.
## Footnote
*Fun Fact: vines can struggle to absorb phosphorus in highly acidic (low pH) soils, too!*
54
What is calcium important for?
Photosynthesis and the structure of plant cells
* Too little calcium can negatively influence fruit set
55
What is magnesium important for?
Photosynthesis (it's found in chlorophyll)
* Too little magnesium can lead to reduced grape yields and poor ripening.
56
Why does soil pH influence nutrient availability in the soil?
Different nutrients become more or less available at different pH levels.
57
What can you add to soil to make it better at holding nutrients?
**Humus** -- organic matter formed by the partial decomposition of plant material by soil microbes and earthworms. It has a spongey texture.
58
The most important physical elements of a soil are its ____ and \_\_\_\_.
**Texture** and **structure**
59
When someone refers to a soil's **texture**, to what are they referring?
**The proportions of the mineral particles of sand, silt and clay**.
_Finely textured soil_ has high proportion of clay; clay particles are small and effective at holding water and nutrients.
_Loosely textured soil_ has high proportion of sand; sand particles are large, drain easily, and are poor at retaining nutrients.
Between clay (small particles) and sand (large particles) are silt and loam (both have particles intermediate/moderate in size)
60
When someone refers to a soil's **structure**, to what are they referring?
**How the mineral particles in the soil form aggregates (crumbs)**.
The size, shape and stability of these crumbs are important for determining water drainage, root growth and soil workability.
Finely structured soils have more clay = larger crumbs that are difficult to penetrate.
Loosely structured soils have more sand = smaller crumbs that are easy to penetrate.
61
A region's climate is defined as:
The annual pattern of temperature, sunlight, rainfall, humidity, and wind averaged out over several years (~30 years).
62
What are the five models used to classify climates?
1. **GDD** (Growing Degree Days, created by Amerine and Winkler, 1944);
2. **Huglin Index** (1978);
3. **MJT** (mean January/July temperature, 1980);
4. **GST** (growing season temperature);
5. **Köppen’s** classification (1900).
63
How do you calculate GDD (growing degree days) in Celsius and Farenheit?
For Celsius, take the average mean temperature of a month in the growing season and subtract 10, then multiply this by the number of days in that month.
For Farenheit, take the average mean temperature of a month in the growing season and subtract 50, then multiply this by the number of days in that month.
Do this for each month in the growing season (April - October in the Northern Hemisphere, October - April in the Southern Hemisphere) and add together the totals to get the GDD.
64
How many zones, or groups, are there for GDDs (also known as Winkler zones)?
Five
## Footnote
Winkler zone 1, the lowest, is a cool climate.
Winkler zone 5, the highest, is a very hot climate.
65
Where is the Huglin Index widely used, and what other model is it similar to?
Used in Europe
Similar to GDD
66
How is MJT (mean January/July temperature) calculated?
It's the mean temperature of either July in the Northern Hemisphere or January in the Southern Hemisphere.
67
How is GST (growing season temperature) calculated?
It's the mean temperature of the whole growing season.
68
What are the three broad terms used to categorize climates?
1. Maritime;
2. Mediterranean;
3. Continental.
69
What are the four broad categories used to qualify climates?
1. Cool;
2. Moderate;
3. Warm;
4. Hot.
70
What is the average growing season temperature in a cool climate?
**16.5ºC / 62ºF or below**
71
What is the average growing season temperature in a moderate climate?
**16.5º - 18.5ºC** (62–65°F)
72
What is the average growing season temperature in a warm climate?
**18.5º - 21ºC** (65–70°F)
73
What is the average growing season temperature in a hot climate?
**21ºC** (70ºF) **or higher**
74
Describe a maritime climate.
* Low annual differences between summer and winter temperatures;
* Rainfall evenly spread throughout the year.
## Footnote
Example: Bordeaux
75
Describe a mediterranean climate.
* Low annual differences between summer and winter temperatures;
* Dry summers;
* Rainfall tends to fall in the winter months.
## Footnote
Examples: Napa Valley and Coonawarra
76
Describe a continental climate.
* Extreme differences between summer and winter temperatures;
* Short summers;
* Cold winters;
* Temperatures change quickly in the spring and autumn.
## Footnote
Examples: Burgundy and Alsace
77
Vine growth, grape ripening, and subsequent wine style and quality can be influenced by variations in what 2 things?
**Temperature** and **timing of rainfall**
78
Climates with even levels of rainfall throughout the year, such as maritime climates, are less likely to experience:
* water stress
* humidity
* fungal disease
Water stress
79
What is continentality?
Continentality is the difference of annual mean temperatures between the coldest month and the hottest month in a region.
## Footnote
*Regions with high continentality have big temperature differences between their coldest winter months and their hottest summer months, e.g. Burgundy.*
*Regions with low continentality have less of a difference in temperatures throughout the year, e.g. Bordeaux.*
80
What is the difference between climate and weather?
Climate is what you expect; weather is what you get.
Climate is a region's expected, annual average of temperature, sunlight, warmth and rainfall over time;
Weather is what happens day-to-day and what you see outside your window.
81
What can weather, of either extreme, in a particular vintage influence in the vineyard and in the fruit?
* Sugars;
* Acidity levels;
* Tannin ripeness;
* Aromas;
* Yields;
* Disease.
82
Climate change broadly affects (and increases) what?
* Evapotranspiration (thereby increasing water stress);
* Geographical distribution of rainfall;
* Greater weather variability;
* Greater frequency of extreme weather events.
83
What are some of the viticultural side effects of warmer temperatures caused by climate change?
* Vine cycle is faster;
* Rate of sugar accumulation increases;
* Acidity levels decrease faster;
* Rates of aroma and tannin development are NOT affected, so grape ripening can be problematic.
