Chapter 3 Flashcards
The Growing Environment
What are the effects of temperature at each stage of the vine growth cycle
- Dormancy: Cold temps (< 10C) ensure dormancy, while extreme temps cause winter freeze/vine damaged
- Budburst: Temps >10C stimulate budburst, which is more successful/uniform if significance rise in temp (eg continental climates). Warm soil temps also promote budburst. Cold temps that bring spring frost harmful to buds, which can reduce yields
- Shoot & leaf growth: 18-33C (large range so usually isn’t a limiting factor at this phase)
- Flowering & fruit set: warmer temps needed for uniform flowering (>17C) and fruit set (26-33F), cold damp conditions result in problems in flowering & fruit set and reduction in yield (possibly the quality of grapes)
- Bud fruitfulness: warms temps above 25C is best increase bud fruitfulness next seasons → affect yields
- Grape ripening: warmer temps = faster sugar accumulation (due to optimum rate of photosynthesis (18-33C) and increased transpiration promotes movement of sugar into grape); also malic acid degradation at warmer temps;
- Extreme heat pair with dry conditions causes photosynthesis to slow or stop → slows grape ripening/vine growth
What are the effects of sunlight on grape development grape
- needed for photosynthesis (fog = slows it down)
- Color: enhances development of anthocyanins (color pigments)
- Aromas: reduces methoxypyrazines, associated w/ increased terpenes
- Tannins: leads to greater accumulation of tannins pre-veraisom / promotes tannin polymerisation after veraison (reduces bitterness)
- Acid: warms the grapes, increasing rate of malic acid used in respiration, lowering acidity
- prolonged sunshine = sunburn grapes (effects quality and yields) - need canopy management
- associated w/ **successful fruit set **and exposure of compound buds to sun promote bud fruitfulness for next season
How do foggy days impact vine growth and grapes
foggy days hinders the sunlight, which hinders photosynthesis
How does sunlight impact different aroma precursors
- reduces mythoxypyrazines
- associated with increased terpenes
How does sunlight impact grape color
Sun enhances development of anthocyanins (color pigments)
How does sun impact tannins of grapes?
- Pre-veraison: helps w/ tannin accumulation
- Post-veraison: helps with polymerisation = less bitter tannins
How does sunlight impact acidity in grapes
sun warms the grapes, increasing rate of malic acid being used up by respiration
What is the problem with prolonged sunshine for grapes?
- sunburn = reduced yields and quality
List the natural factors affecting sun & temperature
- latitude
- altitude
- slopes / aspects
- proximity to water
- winds
- soil characteristics
- mist, fog, clouds
- diurnal range
How does latitude impact sun and temperature?
- amount of solar radiation
- the intensity of solar radiation (due to earth curved shape)
- hours of solar radiation (hours of sunlight)
What is the relationship between solar radiation and latitude
lower latitude = higher solar radiation and more intense solar radiation
if all else equal, how do grape characteristics differ in high altitude compared to low altitude
High altitude region:
* higher sugar
* lower acidity
* riper aromas
* riper tannins (black grapes)
* more color intensity
Ideal latitude for wine production
30 to 50 degrees latitude on each side of equator
How does number of daylight hours impact growing season for higher altitude regions?
during the growing season, there’s much longer daylight hours in summer = longer duration of photosyntehsis = enough sugar for ripening grapes
How does altitude impact sun and temperature?
- intensity of sun (higher altitude = higher intensity)
- diurnal range (higher altitude = higher diurnal range)
Why do higher altitudes have higher diurnal range?
the ground absorbs energy from the sun during the day & releases energy at night (meaning heat is retained);
at higher altitudes, air is thinner so heat escapes quickly
How do slopes & aspects impact sunlight and temperatures
- direction of the slope (aspect) determines how much solar radition vines get
- steepness of slopes (steeper slopes can increase angle at which sun hits vineyard, nearer to perpendicular, making it more intense and direct)
what is aspect in terms of vineyards
the direction of which vineyards are planted on slopes
Which aspect/direction gets most sun in S. hem and N. hem
nothern hem - south facing slopes
southern hem - north facing
Why might a winemaker in warm climate plant on slopes that face away from the sun?
to limit heat and sunlight to grow earlier-ripening varieties (otherwise they ripen too fast in warm climates - too much sugar, havent develop complex aromas yet) or produce wines w/ less alcohol and more acidity
what are the benefits of east-facing slopes
- morning sun heats up vineyard when air temp/soils temps are lowest
- helps dry out the morning dew on the canopgy to prevent fungal disease
What are other benefits of planting on slopes (outside of sunlight and heat)?
- well draining, poor soils
- shelter from winds and rain
- protection from frost
What are the challenges with slopes?
- soil erosion
- unable to use machinery
What are large bodies of water?
lakes and seas
How does a large body of water affect temperatures during the day?
Water heat up more slowly and land, keep the air above it cooler than air above land.
Warm air over the land rises, drawing in cooler, humid air from above the water, creating cooling afternoon breeze
How does large body of water affect local temperatures at night?
bodies of water retain heat longer (cool down more slowly) than land, so it keeps the surrounding area warmer at night
How does proximity of water impact local temperatures across different seasons?
Water has a moderating influence, so cooler summers and milder winters
How does spring frost occur?
when cold dense air (at 0C or below) settles near the ground overnight and forms cyrstals on vine tissues
Why is the proximity to deep lakes beneficial in Finger Lakes vineyards or cooler climates?
- spring frost prevention (due to movement of air - warmer air from water or winds mix with cold air near ground and prevent temps dropping to low)
- temperature regulation: reduces severity of winter freeze (which can damage or kill the vines)
- air circulation: reduce humidity, lowering risk of fungal disease like mildew
- extended growing season: body of water releases stored heat slowly as temps drop in autumn, keeping surrounding area warmer for longer
- reflected sunlight: water reflects solar radiation providing more sun (enhancing photosynthesis - more sugar for ripening)
Why is the proximity to large bodies of water beneficial for warmer climates?
moderating influence of cooling afternoon freezes
How does San Pablo Bay influence grape grown and grape growing in Carneros, California?
cooling afternoon breeze from San Pablo bay allow early-ripening varieties like Chard and Pinot to thrive - more slower, even ripening process; slows sugar accumulation and maintain acid (crucial for sparkling wine)
helps with fungal disease risk
how do bodies of water provide a moderating effect on cool climates AND warm climates?
Cool climate: water heats up and cools down slowly, so in cooler climates when land loses heat quickly at night, the water keeps things warm
Warm climate: land heats up quickly, so the afternoon breezes help provide coolness to prevent excess heat stress and maintain acidity in grapes
How do seas/lake influence growing environment compared to oceans?
- lakes/seas providing a moderating effect (warms up cool climates; cools down warm climates)
- ocean currents transport warm or cold temps over long distances
How do ocean currents influence temperatures in wine regions?
warm currents (eg Gulf Stream in Bordeaux) carry warm water to raise temperatures
cold currents (eg California current) carrys cold water and cool down coastal areas.
cold currents also increase fog and breeze, which could allow for slow ripening and retaining acidity
Why can Margaux in Bordeaux grow Cabernet Sauv, while Willamette Valley focuses on Pinot Noir, even though they are at the same latitude?
Bordeaux is warmed by the Gulf stream and late-ripening varieties like Cab need more warmth as they require longer time to reach full ripeness
Willamette Valley is cooled by the California current, favouring early-ripening varieties
How do mountains influence cliamte of coastal regions in Western USA?
mountains can block ocean influence and provide drier, warmer conditions
What effect the main effects of large bodies of water and oceans in a growing environment?
- moderating influence of large bodies of water
- warming or cooling influences of ocean currents
- sun light reflected off lakes/seas beneficial for cool climates with limited sunshine
What is el nino and how does it effect vineyards?
A climate cycle where warm Pacific water moves east, bringing heavy rain and hurricanes to South America and California, while making Washington and Oregon warmer and drier. In Australia, it causes hotter, drier conditions and drought.
What is la nina and how does it affect vineyards?
A climate cycle where the eastern Pacific is cooler than usual, leading to cooler, wetter conditions in Washington and Oregon but warmer, drier conditions in California and South America. Australia experiences cooler, wetter conditions.
La Niña doesn’t make Australia cooler because of cold ocean water, but rather because of increased cloud cover, rain, and tropical convection blocking sunlight
what influence does winds have temperature?
areas near large bodies of water may experience cooling breeze during the day, moderating the diurnal range (keep temperatures from being too extreme)
asides from influencing temperature, what other impact do winds have on vines
- reduce humidity and promote air flow in the canopy - reducing fungal disease risk
- increase evapotranspiration, which means the vine’s water needs may be higher than in non-windy areas (note: in regions with high temps and low humidity like Mediterranean climates, evapotranspiration is high) - can result in water stress if not irrigated
- wind can damage vines, impact fruit set, reduce yields
during growing season, vines lose water through evaporation and transpiration
What are some ways grape growers protect vines from winds? what do they have to be mindful of?
Plant trees at edge of vineyards to act as windbreak (but trees can compete for resources)
put up fences - but require maintenance and less aesthetic
How do the different traits of soil influence temperature and sun?
- soil drainage - free-draing soils warm up more quickly
- color of soil - light color soil reflect energy from solar radiation and give extra light energy to lower parts of canopy
Why is it beneficial for cool climates to have free-draining soils? What are the risks?
Benefits:
* soils heat up more quickly in spring encouraging starch breakdown in roots –> promoting earlier budburst and shoot growth, hence potentially extending the growing season)
* warm soils encourage root growth, meaning vine can absorb more water and nutrients
Risks:
* early budburst could mean greater spring frost damaging shoots and buds
What is the effect of light colored cs dark color soils on vines.
- light color soils -help reflect energy from solar radition and provide extra light energy to increase photosynthesis and ripening in cool climates and in late ripening varieties
- Dark soils (like those in Etna) - absorb more heat/energy and re-radiate most of it when temps are cooler (at night); can be useful in cool climates (when temps drop at night and the soil helps maintain some warmth). also helpful for late-ripening varieties. The extra warmth allows them to fully develop (as they take longer to mature) This allow for development of color and degredation of acid to continue during the night
Why do Sancerre and Champagne and light color soils go well together?
The chalk, light colored soils in Sancerre can help reflect energy from solar radition and provide extra light energy to increase photosynthesis and ripening in cool climates.
Also Sauv Blanc is a late-ripening variety so this soil helps acheieve proper ripeness
Effect of dark-colored soils & instances where it can be useful
Dark soils absorb more heat/energy (so extram warth during the day) and re-**radiate/release most of it when temps are cooler **(at night);
Good for cool climates & regions with short growing season - helps maintain some warmth at night, helping with frost and extends ripening
Good for for late-ripening varieties. Extra warmth = more time to fully develop more sugar, flavor and tannins; (sugar accumulation, acid degradation (warmth boosts respiration, burns malic acid) to continue during the night
dark soils like volcanic soils in Etna
Why is it beneficial for cool climates to have dark soils for ripening
dark soils help absorb the heat and re-radiates it at night (when temps are cooler), meaning more warmth at night allowing - acid degradation (which can be high in cool climates) and further color development.
Why is it beneficial for late ripening varieties to have dark soils?
late ripening varieties need more time and warmth to ripen, so dark soils help absorb heat and release/re-radiate it during nights (or at cooler temps), meaning more hours of warmth
Are stony soils effective at absorbing and releasing heat at night? Why or why not?
Stony soils, especially when the underlying soil is slightly damp, absorb heat during the day and release it at night.
What is mist?
How is mist formed?
formed by tiny drops of water collecting in the air just above the area of ground or water; usually when warm air is rapidly cooled causing water vapour in air to condense (ex: warm air over body of water meets cooler conditions above land)
What is fog?
Dense mist;
When in the day can mist and fog form?
diff times of the day in diff regions but mostly in mornings
like Sonoma, Napa, Leyda Valley and Sauternes
Impact of mist, fog and cloud cover in the vineyard
- limits sunlight and slows down photosynthesis
- lowers temperatures
- slows sugar accumulation
- reduces acid degradation
Is fog/mist/clouds beneficial for cool or warm climates? why?
warm climates - provides cooler temps, reducing acid degradation and slow down sugar accumulation
Are fog/mist/clouds beneficial for early ripening or late ripening varieties? why?
Early ripening varieties b/c:
Provide cooler temps and less sun to slow down ripening.
Allows grapes to have more time to develop complex flavours.
Slow sugar accumulation (before tannins and aromas develop).
Helps maintain acidity (less malic acid degradation)
What are challenges with mists and fog?
they are made up of water droplets and occur at ground level, so they increase in humidity and increase risk of fungal disease or noble rot (with dry sunny afternoons)
What are the conditions for noble rot?
- Morning fog, humidity conditions
- warm sunny dry afternoon - mositure evaporates cuasing fungus to dehydrate grapes
What is diurnal range
diff between day time and night time temps in a vineyard or region
Do the following factors have: Higher or lower diurnal range:
* continental climates
* high altitudes
* nearby large bodies of weater
- continental climates = high
- high altitudes = high
- nearby large bodies of weater = low
Why is a larger diurnal range thought to be favourable in warm/hot climates (like Ribera del Duero or Mendoza)
a cooler period during the night helps slow respiration of malic acid and beneficial for formation of anthocyanins - color pigments (day time temps too hot)
Why is lower diurnal range thought to be favourable in cooler or modereate climates (Mornington Penisula or Mosel)?
night time temps allow ripening (e.g. acid degradation and anthocyanin snythesis) to continue
may also have influence on aroma compounds - Warm night time temps associate with breakdown of methoxypyrazines
In cool climates, a lower diurnal range helps avoid frost stress, promotes steady ripening, maintains acidity, and enhances balanced flavors
Example of where cold night time temps beneficial for cool climates (exception to general theory/trends)
Wachau, AT - top sites see cool days and cold nights
exact reasons unknown
Generally how much water do vines need in cool climates and warm climtes
Cool climate: 500mm rainfall per year
warm climate: 750 mm
List all the reasons why vines need water
- to survive
- ripening and vine growth
- photosynthesis
- turgidity (so it doesnt wilt)
- regulating its temp
- acts as a solvent for nutrients in soil
Explain the interplay btw water, stomata and transpiration
as water diffuse out of stomata (when it’s open), CO2 comes resulting in photosynthesis; as water diffuse out, more water pulled in via transpiration where vine pulls water from soil upwards
How do these water levels effect the the vine?
* sufficient water
* lack of water
* extreme water stress
* excessive water
**sufficient water **= open stomata = photosynthesis for vine growth (more leaves = more photosyntheiss and vine growth) and grape ripening
**lack of water **= partially closed stomata = no Co2 in = slows/no photosynthesis = no sugar for energy = slows vine growth and ripening
**extreme water stress **= vine shuts down, leaf loss and vine death
excessive water = during spring and early summer too much vegetative growth (like leaves) that takes away/competes resources with/from grape ripening = delay or compromises grape ripening
Which stage of vine cycle do grape grows want mild water stress? Why?
Before veraison to inhibit more vegetative growth
Explain all the challenges and impact of too much water during spring/early summer (after veraison)
- increase in vegetative growth, competing and take away resources with the ripening = delays & compromises ripening
- shading of the fruit = reducing formation of anthocyanins, tannins, aromas, less tannin polymerisation, higher levels of methoxypyrazines
- dense canopies = poor ventilation = fungal disease risk in humid climates
Name some regions where lack of rainfall during growing season is an issue
CA, AU, AR, SA
Impact of too much or too little water during ripening
- too much = dilution of sugar in grapes
- too much = grape splitting (encouraging botytris)
- water deficit = early onset of grapes shrivel, reduce ability to reach desired levels of ripeness
What are the effects of water on soil for bud bursts ?
- damp soil early in the season = delay budburst = shorten ripening
- warm soil = encourage budbursts + encourage root growth, which helps with uptake of water & nutrients
What is the impact of hail?
major damage to all green parts of the vine = lower yields + reduce quality of remaining fruit
When are negative effects of rainfall be during pollination and fruit set?
uneven ripening and lower yields
how does rainfall impact humidity?
Rain creates a humid environment leading to fungal diseases like powdery mildew and botytris
How does low-humidity air impact, vine water use as it relates to evapotranspiration and grape ripening?
Low-humidity air ** increases evapotranspiration**, leading to potential water stress.
Also associated with grape transpiration, which accelerates sugar accumulation in the grapes.
Evapotranspiration is the combined process of:
Evaporation – Water loss from the soil and vine surfaces into the air.
Transpiration – Water movement through the vine, which is then released as vapor from the leaves.
How does water affect growing environment:
- soil
-hail
-rainfall
-proximity to large bodies of water
-ocean currents
- Soils - damp vs warm soils impacting budburst
- hail = damage vines
- rainfall = creates humidity, impacts pollination and fruit set
- large bodies of water = moderate diurnal and seasonal temps
- ocean currents = can either increase or decrease avg temps of growing season
- lakes/rivers = encourage breezes, reducing frost
- proximity increases humidity = fungal disease or botrytis
ocean currents impact TEMPS
lakes/rivers impact AIR (temps)
How do lakes / rivers reduce frost risk?
- heat retention (at night so temps dont drop too low)
- air movement = mixture of cool land air and warmer river/lake air, prevents frost
Why are main regions that are famous for sweet botrytised wines near large bodies of water? Give examples of regions
noble rot needs - damp misty mornings, dry warm afternoons
* Bodies of water: increase morning humidity - development of botrytis (at night, land cools faster, warm water releases moisture in the air, causing mist/dog in morning and humidity)
not sure: * afternoon drying - (sun heats land up, helps with evaporation and as land heats up, warm air rises pulling in drier air (from large bodies of water)
How does rain occur?
Rainfall caused by water vapor condensing and precipitating.
Warm temps cause moisture from the land to evaporate rise. As warm moist air rises, it cools and condense into clouds, eventually leading to rain
How can mountain ranges impact rainfall patterns?
can force winds of warm moistened air upwards over high altitudes, cause water vapor to cool condense and precipitate
depending on what side you are of the mountain can impact rainfall one side experiences more rainful and other side is blocked and sheletered from rain-bearing winds
How do mountain ranges impact rainfall and climate for WA state?
West side of casacade mounts (pugent sound ava) experiences wetter, cooler climate
East sideo of casacade mounts (columbia valley) experiences drier, warmer climate mountains provide shelter from rain-bearing winds
List the natural factors that effect water availbility:
- rainfall
- typography - mountain ranges
- characteritistcs of soil and land
- evapotranspiration rate
What soil characteristics influence the availability of water for a vine’s roots?
- soil depth
- soil’s water drainaged
- soil’s water-holding properties (function of soil’s texture and organic matter content
what deteremines soil drainage and water retention
the soil texture and structure
why is irrigation needed in hawke’s bay’s Gimblet Gravels when rainfall can be 1000M
its free-draining gravel soils and doesn’t hold water
Jerez, Spain:
* What is its rainfall level per year?
* How much rain does it receive in summer?
* Does it need to irrigate - why or why not?
- 650mm per year
- virtually no rain during summer season
- Mostly albariza soil - a clay soil with good water retention that releases water slowly to the vines.
- Albariza soil forms a crust when dry, which reduces evaporation
Impact of water-logged soils
water logged soils are poor draining, which reduce amt of oxygen available to roots, which slows its growth and eventually kills the vine
water fills up in the soil pore instead of air
wha are benefits of and challenges of slopes in terms of soils water availabity
- pro: slopes allows more run off, so in rainy regions, less penetration of water into soil and roots
- con: run off casues soil erosion and leaching of nutrients
- erosion means thinner soil, limited area over which vines obtain water & nutrients
what is evapotranspiration rate
the amt of transpiration from the vine combined with evaporation of water from soil, therefore the rate at which water is no longer available in the soil b/c its taken up by vine or atmosphere
What factors / climate conditions influence Evapotranspiration rate?
humidity, wind, temperature
Why do some regions have higher evapotranspiration rates than others? Give examples
regions with drier, hot, windy climate have higher Evapotranspiration rate than cooler, humid climates
ex: mendoza and patagonia
where to vines get their nutrients from? what are nutrients need for? do they need low or high levels of nutrients?
- nutrients from soil
- needed for vine growth and influence yield and grape composition
- low levels
List the most important nutrients for vines
- nitrogen
- potassium
- phosphorus
- calcium
- magnesium
Aside from the main 5 main nutrients, what other nutrients play role in vine growth and reproduction?
sulfur, manganese, boron, copper, iron and zinc.
What is nitrogen? How does nitrogen as a nutrient in soil play a role?
nitrogen is a component of proteins and cholorphyll (needed for phtotosynthesis)
its impact vine vigor, grape quality
How much nitrogen is ideal for the vine? What happens if too much or too little nitrogen?
a restricted supply is ideal
too much = excessive vegetative growth
* take away from ripening
* too much shading or fruit and buds
* poor ventilation (fungal disease risk)
too little:
* reduced vigor
* yellowing of leaves
* grapes w/ low nitrogen has problems for fermentation
What is the role of potassium in the soil? what happens when too much or too little?
- role: help regulate flow of water in the vine
- too high = problems with magneisium uptake (as it competes with uptake) - lead to reduced yields, poor ripening
- too high also impact wine quality = higher pH
- too low = low sugar accumulation in grapes, reduced grape yields and poor vine growth (potassium regulates processes like photosynthesis and transporting of sugar to grapes)
Phosphorus: what is its role? how much does it need? what happen if there’s a deficiency
important for photosynthesis;
need only small amt and usually enough present in soil;
deficiency = poor developed root systems –> diminishing uptake of water and nutrients –> reducing vine growth and yields
What is the role of calcium in soil? What happens when its in deficiency?
mportant role in structure of plant cells and photosynthesis;
deficiency is rare but negative influence on fruitset
Grape cell structure –> Fruit set
What is the role of magnesium in the soil? Where is it found? what happens when its in deficiency?
- found in chlorophyll
- important for photosynthesis
- deficiency = reduced grape yields and poorer ripening
What natural factors affect nutrients?
- Same SOIL factors that affect water availabilityl (need to dissolve in water) including: soil drainage, soil water retention (function of soil texture and organic matter), soil depth
- Soil pH (impacts nutrient avail -soils w. higher pH have poor iron -leading to chlorosis)
- Organisms for mineralization (converts organic nutrients to inorganic compounds for uptake)
- Soil texture (clay - good at holding vs sand bad at holding nutrients; humus can help)
- Slopes (less fertile, nutrient leaching, thinner soil -roots can’t go deeper for nutrients; les soil volume)
How does soil pH affect nutrient availability
diff nutrients become more or less avail at different pH levels.
What nutrient is LOW in high pH soils like limestone
Iron nutrient levels are poorly available
What can happen if Iron is poorly available in soils with high pH (low acidity)
Chlorosis - condition where leaves turn yellow and photosynthesis stops –> impacts grape ripening and yields
Highly acidic soils (low pH) can result in a deficiency in which nutrient
highly acidic soils (low pH) means vines may struggle to take up phoshorus
How does the vine take up organic nutrient compounds found in soil?
Organic nutrient compounds not avail in a form the vine can take up - so needs to convert to inorganic compounds
Via the process called mineralisation: where organisms that live in the soil (worms, bacteria, fungi) eat the organic matter and convert it into inorganic compounds.
Difference in organic vs inorganic compounds
- organic compounds = contain carbon
- inorganic compounds = dont contain carbon
What can organisms found in soil do besides mineralisation?
They can convert organic matter to humus
How does soil texture affect ability to hold nutrients? give examples
- diff soil textures have varying ability to hold nutrients
- clay soils = good at holding nutrients
- sandy soil = poor at holding nutrients
Does Humus increase or decrease soil’s ability to hold nutrients
increase
How do slopes impact nutrients in soil?
slopes have thinner soil that’s less fertile than valley floors/plains
What is soil? What is it made up of:
upper layer of earth, typically made up of:
* geological sediment (solid matter like pebbles, rocks, sand etc) that has been moved and depositied into new location (by water or wind)
* organic remains in form of humus
* pores in between the sediment that contain water and air
What is geological sediment? where do they come from?
solid matter like pebbles, rocks, sand that comes from weathering of bedrock (the solid rock below the soil)
What are the most important physical elements of a soil?
its texture and structure
What is meant by the texture of a soil?
texture describes the proportion of the mineral particles of sand, silt, clay
ChatGPT- Soil Texture = The Size of Particles
Texture refers to the physical feel of the soil, which depends on the size of its mineral particles. There are three main types:
• Sand (Large particles, drains quickly, feels gritty)
• Silt (Medium particles, holds some water, feels smooth)
• Clay (Small particles, holds water tightly, feels sticky)
Describe the texture of clay and its effect on the vine
finely textured as clay is made up of small tiny particles so it has larger surface area compared to their volume, so it’s effective at holding nutrients and water
Describe texture of sandy soil and its effect on the vine
Large particles, so smaller surface area to vol = can’t hold much water and nutrients
Loose texture = roots grow easily
How does silt soil properties compare to clay and sand
particles of intermediate size (medium particles)
its properties sit in betwen clay and sand (so it can hold some water & nutrients)
What is loam soil? how does it properties compare?
soil that has moderate proportion of clay, silt and sand –> meaning it has all the best qualities of all three - The best balance between drainage, water retention, and nutrients
may also contain proportion of larger rock fragments (gravel or pebbles) that help improve water drainage, but lower water and nutrient holding capacity
What does the soil structure describe?
Describes how mineral particles in soil form aggregates (crumbs)
What soil properties make up soil aggregates? What does it have an impact on the vine?
Size, shape and stability of these aggregates important for determining water drain, root growth and workability of soil
What is the structure of clay? What impact does it have on the vine?
Clay is sticky and forms aggregates that are hard for vine roots to penetrate and challenging for soil cultivation - vine’s roots limited to cracks or gaps btw aggregates
What is the structure of sandy soil or larger particles like gravel/pebbles?
they’re very loosely structured, more easy for vines roots to move through them
Why is it helpful to have an ecosystem of microbres and organics like earthworms, fungi, bacteria in the vineyard?
- they convert organic matter in nutrient compounds to inorganic matter to allow uptake by vines
- they convert organic matter into humus
What is humus? What is its texture and impact?
- organic matter in the soil formed by partial decomposition of plan material by soil microbes and earthworms
- spongey texture, large surface area to absorb water and nutrients
- helps bind soils together and can help soil retain water and nutrients
What does the suitability of soil for viticulture depends on?
- soil structure
- texture combined with
- how far roots able to penetrade
- the climate where vine is grown
Explain sandy or stony soils suitability for viticulture
- they have poor water and nutrient-holding capacity but may prove suitable if the vine roots are able to grow freely and deeply, giving a large area over which the vine can obtain water
- free drain soils like sany and gravel help with rainy climates (ex Haut Medoc)
what can grape grower do if soil isnt completely suitable?
- Compost added to provide nutrients and improve soil structure
- Irrigation if soils too free draining
How does the color of soil impact heat and light availablity?
- Light soil - reflect sun back into the lower parts of vine canopy during daylight hours
- Dark soils - absorb heat from solar radiation during day and release it slows at night, moderating diurnal range
what is climate defined as?
annual pattern of temp, sunlight, rainfall, humidity and wind averaged out over several years (30 yrs~)
which component of climate do climate classifications mostly focus on?
- pattern of temps and sometimes rainfall
List 4 of the main climate classifications
- Growing Degree Days (GDD)
- Huglin Index
- Mean Temperature of Warmest Month (MJT - mean jan/july temp)
- Growing Season Temp (GST)
Explain Growing Degrees Day GDD model? How is it calculated?
**GDD **= a model of heat summation during growing season
(It looks at how much avg monthly temps exceed base temp, considers how much warmth is actually contributing to the vine growth)
- For Celsius, subtract 10 (the temp in Celcius below which vines cant grow) from avg mean temp of a month in a growing season. For Farenheit, subtract 50
- Multiply by # of days in that month
- make same cal for each month in growing season (april to Oct in N Hem / Oct to april in S Hem)
- add together totals to get GDD
How are climates classified in Growing Degrees Days (GDD) model?
split into 5 bands:
* Winkler Zone I (lowest GDDs) is cool
* Winkler Zone V (highest GDDs) is very hot
Which region(s) used Growing Days Degree (GDD) Climate model?
made mostly for California
Explain the Huglin Index?
similar formula to GDD, but accounts for:
* both mean and max temps
* the increased day lenghts experienced at high latitude
* split into bands with most suitable grapes mapped to the bands
Which region mostly uses Huglin Index?
Europe
Explain MJT (mean tempeature of warmest month) model.
MJT = Mean Jan/Jul Temp
climate model that uses mean temp of either July in N Hem or Jan in S. Hem as well as measures continentality, humidity and hours of sunshine
How many bands for MJT climate model
6 bands, ranging frmo cold to hot
What is continentality
temperature diff in the hottest and warmest month of the year
Explain the GST climate model (Growing Season Tempeature)
- uses the mean temperature of the whole growing season
- these temperatures are grouped into climatic bands (cool to hot)
- very closely correlated to GDD, easier to calculate
- take all mean monthly temps from april to oct and divide by 7 = GST
Aside from climate models, what is the broad classification for climate and what does it consider?
climate categories into 3: maritime, mediterranean, continetal
it considers temp and rainfall patterns
Describe maritime climate?
low annual diff btw summer & winter temps; rainfall evenly spread in the year; (ex: Bordeaux)
Describe mediterranean climate
low annual diff between summer and winter temps BUT rainy winter, dry summers (ex: Napa, Coonawarra)
Describe continental climate
more extreme diff btw summer and winter temps; short summers, cold winters w/ temps rapidly changing in spring and autumn (ex: Burgundy / Alsace)
Define cool climate
avg GST of 16.5C or below
62F
Define Moderate climate
avg GST of 16.5-18.5C
62-65F
Define warm climates
avg GST of 18.5-21C
65-70F
Define hot climates
avg GST >21C
70F
How does continentality impact continental climates
- extreme winter = potential winter freeze
- rapidly increase in temp in spring = even budburst
- rapid drop in temp in autumn = shorter growing season
what are advantage and challenges for grapes for climates with warm summers?
pro: no risk of sugar accumulation
con: sugar accumulate too fast and acid drops to much before tannins, aromas, color reach ripeness
What are challenges of a cool growing season for the final wine
lower in sugar, high in acid in very cool years
whats the benefit of low annual temp differences in maritime and mediterranean climates
long autumns with suitable temps for ripening
Advantages & disadvantages of even levels of rainfall for maritime climate?
Advantage:
* less risk of water stress
Disadvantage:
* execessive vine vigor
* increases humidity - fungal disease (noble rot)
* rainfall in late spring/early summer - poor flowering & fruit set
* water diluation at harvest
Explain how large bodies of water impact a region’s continentality?
They heat up and cool down slower than land, so they have warming effect on surrounding land air in the winter and cooling effect in the summer.
regions by large bodies of water, have low continentality
What is a region’s weather
annual variation that happens relative to climatic avg
How was the weather in Bordeaux in 2013
- cold wet spring = uneven flowering = reducing yields
- humid, rainy harvest = producers had to pick early = low quality and quantity
How was weather in 2016 in bordeaux
good weather during flowering and long warm, dry summer up to harvest - higher quality and volume
What is vintage variation
the signficant impact of weather on style and quality of wines produced in a certain year (influences sugar, acid, tannin and aroma ripeness)
what situation and wine styles don’t want vintage varation?
- non vintae sparkling wines
- many high vol inexpensive wines where consumers want consistency
In what ways can weather impact yields?
spring frost - reduce yields
rainy years - reduce yields due to fungal disease
Why are smaller yields problematic?
- bad for customer relations
- bad for cash flow
Why can larger yields be problematic?
- winery doesn’t have capacity for it
- finding route to market/customers for all the extra wine can be difficult
What are the effects of climate change in the growing environment?
- a rise in temperature (main effect)
- greater evotranspiration, increasing water stress (stop photosynthesis, vine shut down)
- geographical distribution of rainfall (fungal disease challenges or rain harvest dilution)
- increased frequency of extreme weather events (reduce yield and quality)
- greater weather variability
How does climate change’s rising temps affect the wine and its style?
- Speed up sugar accumulation
- Reduces acidity (more respiration burning malic acid)
- Doesn’t quicken ripening of tannins & aromas * Some signature aromas may not develop for that region and grape
- wine has higher pH –> problems in winemaking (due to acid degradation and warmth temps increase potassium uptake)
How are grape growers & wine businesses trying to mitigate effects of climate change:
- Sustainable techniques like renewable energy resources and protecting natural ecosystems
- They also are reviewing things like: site selection, choice of planting material, and efficacy of diff vineyard management techniques
A deficiency in ____ (soil nutrient) results in problems in fermentation
Nitrogen
A deficiency in ____ (soil nutrient) results in high pH of the wine?
Potassium
think avocados, banana, spinach
