The Growing Environment Flashcards
Describe the effects of temperature on each phase of the vine cycle.
- Dormancy - Cold temps (below 10C/50F) cause dormancy, extremely cold temps (-20C/-4F) cause winter freeze/damage
- Budburst -In spring 50F or higher stimulates budburst. Warmer soils can help. Cold temps w frost can damage buds and reduce yields.
- Shoot and leaf growth- needs photosynthesis, which requires warmer temps of 64-91F
- Flowering and fruit set - requires warm temps to be uniform (above 63F for flowering, 79-90F for fruit set). Cold, damp=problems
- Above 77F promotes bud fruitfulness for following season/yields in next growing season
- Ripening - @Warm temps cause faster sugar accumulation (photosynthesis, more transpiration), malic acid degradation, rapid loss of acidity if over 70F, must too acidic if under 59F; methoxypyrazines not broken down as much in cooler climates (herbaceous); anthocyanin synthesis (color development) needs 59-77F
What is the level of sunshine needed for grape growth and ripening?
One third of full sunshine. An Average cloudy day will not slow photosynthesis.
Describe the effects of sunshine at different stages of vine cycle.
- Grape growth and ripening - Sunlight needed for photosynthesis
- Color (anthocyanin) development
- Reducing level of methoxypyrazines (herbaceous aroma/flavor)
- Accumulation of tannins pre-veraison, tannin breakdown after veraison - less tannic bitterness
- Development of compounds like terpenes
- Lowers acidity levels by warming grapes and increasing rate at which malic acid is used in respiration
- Late spring/early summer - sunshine associated w successful fruit set and exposure of compound buds to sunshine promotes bud fruitfulness in next year’s growing season
HAZARD: sunburn - sunny or warm climates need careful canopy management to provide shading (Australia, Spain Priorat, Rhone)
What are terpenes?
Aroma compound responsible for many fruity and floral aromas like grapey notes in Muscat
How does latitude impact temperature and sunlight?
- Latitude - lower latitude = more warmth and sunshine bc solar raditiation travels less closer to Equator = higher sugar, lower acidity, riper aromas, riper + higher tannins
What latitudes are suitable for grape growing for wine production?
30-50 degrees latitude on each side of the Equator
At what rate does temperature fall with increasing altitude? What does this mean for grapegrowing?
Approximately 0.6C (1.1F) over every 100 m increase in altitude
High altitude sites can be good in areas of low latitude that would normally be too hot - altitude tempers latitude heat (eg Salta, Argentina, 3k meters above sea level)
What is aspect?
the direction vineyards planted on slopes are facing
How does altitude impact temp and sunlight?
- Altitude - sunshine more intense at high altitudes; high altitude sites have high diurnal range (bc air is thinner, can’t hold onto as much heat at night, nights are cooler)
How do slopes and aspect affect temp and sunlight?
- Slopes and aspect - facing the sun (south facing in N, north facing in S) will receive more solar radiation than those facing opposite direction; slope increases the angle at which solar radiation hits Earth’s surface, increasing intensity of heat and light (important in high latitudes w less sunlight/warmth) - eg Alsace and Burgundy GC vineyards are on s-e facing slopes; opposite can be achieved in warm climates eg Stellenbosch on south facing slopes (in S hemisphere)
East facing slopes preferred bc they receive morning sunshine, any dew dries out faster and prevents mildew or rot, extends hours of vine growth and ripening
West facing may become too hot bc of afternoon sun - coasts (like Cali or W Australia) can mitigate this w cool afternoon sea breezes
What are other benefits and hazards of slopes?
\+ Shallower, poorer soils Better drainage Shelter from winds and rain (Rhone - mistral) Protection from frosts
-
Soil erosion
Inability to use machinery
Explain how proximity to water impacts nearby vineyards.
Water heats up and cools down more slowly than dry land.
During the day, bodies of water remain relatively cool, lowering the average temp in area.
At night, water retains warmth gained during day and keep slocal area warmer.
Overall effect extends over the year - larger bodies of water give cooler summers and milder winters.
EX - FLX - winter freeze not as severe ; Carneros - cooling afternoon breeze from San Pablo Bay allows early-ripening grape varieties like Chard and PN to grow there
Ocean currents also have effect. EX - Gulf Stream makes BDX warmer for CS; cool Cali current makes Willamette Valley cooler for PN
Radiation from water’s surface can amplify effect of sunshine in cool climates or in cloudy conditions (like Alsace - prox to rivers)
El Niño - warmth + dry conditions to Washington, Oregon, Australia
La Niña - cooler, wetter conditions in Washington, Oregon, Australia; warmer and drier conditions in SA + California
What are the effects of winds?
- Areas near bodies of water experience cooling breezes during the day, moderating diurnal range
- Valleys facing coast or low land mean that winds can be felt relatively far inland; air is funnelled so stronger winds
- Winds over hot land masses can bring warm air (eg Zonda in Mendoza)
- Winds + breezes reduce occurrence of humid air, discourages fungal diseases
- Increase evapotranspiration rate, so vine needs more water in windier areas
HAZARDS - can damage vines and trellising, which lowers yields and increases costs; plant rows of trees at edge of vineyards as windbreaks; fences are less aesthetic and require maintenance
How to characteristics of the soil impact temperature?
- Drainage - free draining soils warm up more quickly (stonier, absorb sunlight). This encourages early budburst in cool climates; OJO spring frosts); also encourages root growth
- Color and texture- light colored soils (chalk, limestone) reflect energy to lower parts of canopy; dark colored soils (volcanic) absorb more energy and re-radiate most of it when temps are cooler at night; stone soils do this well too
What is mist?
Tiny drops of water collecting in the air just above an area of ground or water - happens when warm air is rapidly cooled, causing water vapor in the air to condense
Dense mist = fog
Morning is most common time
Commonly found in: Sonoma, Napa, Leyda Valley, Sauternes
Can reduce photosynthesis - if cloud mists fog are regular than sugar accumulation and acid degradation can slow down (good in warm areas or for early-ripening varieties)
Can increase humidity and incidence of rot
What is diurnal range?
Average difference between day-time and night-time temperatures.
Contintental climates or high altitudes have more diff between day + night temps
High diurnal range favorable in hot or warm climates (Mendoza, Ribera) as is moderates heat and helps retain acid (slows respiration of malic acid) and helps form anthocyanins
In cool to moderate climates, low diurnal range allows to extend ripening into nighttime (acid degradation, anthocyanin synthesis, sugar accumulation) - Mosel, Mornington Peninsula
What are a vine’s water requirements in cool and warm climates?
Cool: 500 mm minimum per year
Warm: 750 mm
What are the effects of water on vine growth and ripening?
Lack of water causes stomata to close up to prevent water vapor from exiting vine; this will block flow of CO2 into leaves, slowing or stopping photosynthesis and stunting vine growth
FIX: irrigation; EX’s: Argentina, California, South Africa, Australia (low rainfall during growing season)
Too much water into late spring and early summer causes vegetative growth to prolong into grape ripening, compete with vine for sugars which can delay ripening.
Plus too much vegetative growth can cause excessive shading (if not managed thru canopy management). This can lead to reduced anthocyanin formation (color), tannins and aroma compounds, less tannin polymerisation (bitter) and higher levels of methoxypyrazines (herbaceous). Also poor ventilation, increasing risk of fungal disease
THEREFORE mild water stress before véraison is beneficial to inhibit vegetative growth
later in ripening period - too much water creates dilution and grape splitting (leading to botrytis); too little leads to grape shrivel and inability to reach ripeness
What are the effects of water on the growing environment?
SOIL TEMP
- Damp soils are cold, which can delay budburst
- Warm soils promote budburst and encourage shoot growth
PRECIPITATION
- Hail can damage green parts of vine (reduced yield + quality)
- Rainfall can interrupt pollination and fruit set (uneven ripening + lower yields)
- Rain causes humidity within vine canopy (increased chance of fungal diseases like downy mildew and botrytis)
BODIES OF WATER
- Large bodies of water can moderate diurnal and seasonal temps
- Ocean currents increase or decrease average temps
- Lake or river encourage breezes, reduces likelihood of frost
HUMIDITY
- water = humidity = botrytis –> Sauternes, Tokaj, Mosel
List the natural factors that affect water availability.
Rainfall (depending on climate, weather etc)
Soil and Land
1. how easily water drains
2. water-holding properties of soil (texture and organic matter (stones are hot, free-draining, clay is cool, water retaining)
3. soil depth
4. topography - slopes have more run-off and less water available, more soil erosion so thin soil layers
Evapotranspiration rate - amount of transpiration from vine, combined w evaporation of water - rate at which water is not available, depends on humidity, temperature, wind
What factors affect rainfall?
- Soil’s water-holding capacity and depth moderate
- Irrigation may be used if not enough rainfall
- Topography –> mountain ranges create rain shadows (one side experiences rainfall, mountains block other side from rain-bearing winds so it has drier conditions) - EX Washington State- Puget Sound vs Columbia valley
What are the most important nutrients for a vine?
- Nitrogen
- Potassium
- Phosphorus
- Calcium
- Magnesium
Describe the effect of nitrogen on vine health.
Important for vine vigor and grape quality
Too much causes excessive vegetative growth (which causes poor ventilation in canopy and excessive shading of fruit and buds which can lead to less color (anthocyanin), tannins and aroma, more bitter tannins (less polymerisation), higher levels of methoxypyrazines (herbaceous), less bud fruitfulness in compound buds in next season
Too little causes reduced vigor and yellowing of vines
Describe the effect of potassium on vine health
Essential for vine growth and regulate flow of water
Too high - slow uptake of magnesium = reduced yields and poor ripening; high level of potassium within grapes, which lead to high pH
Too low- low sugar accumulation, reduced grape yields, poor vine growth
Describe the effect of phosphorus on vine health.
Important for photosynthesis
Vines need only a small amount
Too little results in poorly developed root systems (hence inability to take up enough water and nutrients)
Describe the effect of phosphorus on vine health.
Important for photosynthesis
Vines need only a small amount
Too little results in poorly developed root systems (hence inability to take up enough water and nutrients)
Describe the effect of calcium on vine health.
Important role in structure of plant cells and photosynthesis.
Too little can have negative influence on fruit set
Describe the effect of magnesium on wine health.
Found in chlorophyll and has key role in photosynthesis.
Deficiency results in reduced grape yields and poor ripening
Explain what factors influence nutrient availability
- Water availability (bc nutrients dissolve in water)
- Soil pH
- Biodiversity, soil life and ecosystems encourage organisms to convert organic matter into available forms
- Soil texture - clay can hold nutrients, sand is poor
- Topography - soil on slopes are thinner and less fertile
What are the components of soil?
- Geological sediment
- Organic remains in the form of humus
- Pores in between sediment that contain water and air
What are the most important physical elements of a soil? Explain.
- Texture - this describes the proportions of the mineral particles of sand, silt and clay
- clay = hold water and nutrients
- silt= in between clay and sand
- sand= poor water retention/good drainage but poor nutrient retention
- loam = clay + silt + sand
- gravel/pebbles= good water drainage but poor nutrient retention - Structure- describes how the mineral particles in the soil form aggregates, which determines water drainage, root growth and workability of soil
- clay= sticky, hard for root penetration and soil cultivation
- sand, pebbles, gravel = need clay or humus to bind together
- Suitability of soil for viticulture depends on texture and structure of soil combined with how far the roots are able to penetrate. Also depends on climate in which vine is growing (eg free draining soil in rainy climates)
- Light-colored soils reflect sunlight back into canopy during daylight hours; dark colored soils absorb heat from solar radiation during day and release it slowly during the night, moderating diurnal range
Define climate.
the annual pattern of temperature, sunlight, rainfall, humidity and wind averaged out over several years (30 years is the timescale generally agreed)
How is climate classified?
- Growing Degree Days - grouped in five bands Winkler Zone I - V
- The Huglin Index- same formula as GDD, but takes into account mean and max temps, includes suitable grape varieties within bands
- Mean Temperature of the Warmest Month - July or January mean temp plus measures of continentality, humidity, sunshine hours
- Growing Season Temperature - Mean temp of whole growing season
List and describe the main climate categories
- Maritime - low continentality (diff between summer + winter temps), even rainfall throughout the year, ex. Bordeaux
- Mediterranean - low continentality, rainy winters, dry summers ex. Napa Valley, Coonawarra
3, Continental - higher continentality, short summers, cold winters, ex. Burgundy and Alsace
List the main temperature bands.
Average GST: Cool - 16.5C / 62F or below Moderate- 16.5-18.5C / 62-65F Warm - 18.5-21C / 65-70F Hot- 21C / 70F or above
Define weather.
The annual variation that happens relative to the climactic average.
Can be referred to as vintage variation when it influences style and quality of wine produced.
Can affect how wine is made in winery and yields.
IMPORTANT TO DO
re- read (and KNOW ) pages 42-46 of book
