5 - The Growing Environment Flashcards
What are the stages of annual growth cycle of vine?
winter: dormant
spring: budburst happens, start of growing season
late spring and early summer: vine flowers and small grapes form. fruit set.
through summer: grapes grow, still hard and green with high acid and no sugar.
late summer and early autumn: grapes ripen, swell with water, sugar rises, acid drops and flavors develop. veraison is first sign of ripening.
autumn: grapes are harvested. growing season comes to end.
What are teh 5 things a vine needs to complete annual cycle?
Heat: defining factor that determines which varieties can be grown. if temp below 10 degrees C, vine will not grow.
Sunlight: vine uses sunlight to combine CO2 and water, to produce glucose and oxygen (Photosynthesis).
CO2
Water
Nutrients: vine combines glucose with nutrients from soil to support its growth and ripen its grapes.
What are factors affecting heat?
latitude: vineyards usually between 30 and 50 degrees north and south of Equator for temp needs.
altitude: higher altitude, cooler it is.
ocean currents: major currents can warm or cool certain regions.
fog: helps cool.
soil: dark or stony soils absorb and reradiate heat from sun, helps ripen fruit. moist soils on other hand do the opposite and conduct heat from vine.
aspect: direction in which slope faces. Aspects facing Equator receive most heat. in Northern Hemisphere, south facing slopes get most warmth. Southern Hemisphere, north facing slopes get most warmth. Steeper slopes benefit most from the effect of aspect.
What is the temperature difference between coldest and hottest months known as?
continentality
How do bodies of water affect continentality?
bodies of water tend to heat up or cool down more slowly than land. Therefore areas near large bodies of water have lower continentality. wine regions located inland have more temp extremes and high continentality.
T/F: region’s continentality determine the length of growing season and impacts total amount of heat available to vine and choice of grape variety
True.
What is the difference between daytime and night-time temperatures known as?
Diurnal range
What is the effect of a large diurnal range in a warm or hot climate?
cool nights can produce wines that are fresher and aromatic compared with smaller diurnal range (cool nights slow loss aromas and acid during ripening)
what is the effect of proximity to seas and lakes on diurnal range?
reduces the diurnal range (bodies of water hold enough warmth to keep vineyards warm at night, and cool during day)
how does cloud cover influence diurnal range?
on clear nights (no clouds), temperatures drop more quickly. this increases diurnal range.
on cloudy days, temperatures rise more slowly because sunlight can’t heat ground directly. this reduces diurnal range.
what happens if temperatures fall below -20degrees C?
vine can be damaged or killed by winter freeze. the graft is part of vine most at risk. ‘earthing up’ is used (earth used to cover and protect graft).
what problems occur if the winter is mild or there is no winter (in subtropical climates)?
vine will not have a dormant period, may produce more than one crop each year. vine’s life will shorten and grapes willb e lower quality.
also, bc of mild summer, larger populations insect pests survive to attack vine following summer.
How do spring frosts occur?
When cold air below 0 degrees C collects at ground level, it freezes water vapor on ground or vine. This can kill newly burst buds or young shoots.
what are 4 main forms of protection against spring frosts?
heaters
wind machines
sprinklers
thoughtful vineyard design (planting vineyards on slopes and avoiding depressions since cold air collects in low areas). vines in middle of slope are at least risk. vines can also be trained high to avoid cold air
What are problems associated with too-cold temperatures? too-hot?
too-cold: budburst may be delayed, which shorted growing season and does not allow enough time grapes ripen. flowering and fruit set can also be disrupted, yield smaller crop of grapes
too-hot: during summer extreme heat will slow vine activity until it eventually stops. prevents proper ripening. vine may even die.
How do latitude, seas and lakes, and aspect affect sunlight?
latitude: the further from equator, longer the day length (extra sunlight)
seas and lakes: vineyards near seas and lakes often have cloud cover, whereas in center of land masses they are sunnier. sometimes vineyards above rivers or lakes receive sunlight reflected from water
aspect: aspect affects amount of sunlight (this is enhanced by steepness). vineyards facing equator get most sunlight.
what are sources of water in vineyard?
Rainfall
irrigation:
1. drip irrigation (most advanced and expensive). vines are individually watered by sprinklers controlled by computers.
2. sprinklers: widely used by waste water and create damp conditions increase risk of disease. also used for frost protection
3. flood irrigation: only possible in flat vineyards or gently sloping and where there is a lot of access to water
common water hazards?
drought - vine will stop transpiration (drawing up water to its leaves).
too much water - if vine has too much water the vine will continue grow shoos and leaves during ripening. leaves less sugar for ripening grapes. the extra shoots and leaves create canopy that shades grapes and restricts ripening. waterlogged soil can also cause roots to die.
Rainfall - heavy rainfall disrupts flowering and fruit set and reduces number of grapes formed. Also - damp conditions encourage spread fungal disease. Heavy rain before harvest time causes grapes to swell and dilutes flavors.
Hail - hail can damage grapes and vine itself, can even destroy entire crop. Some areas particularly prone to hail like Mendoza. Netting can be used to protect vineyard from hail, but can be expensive.
What is the annual pattern of temperature, sunlight and rainfall averaged out over several years?
climate (does not change year to year)
How does weather differ from climate?
Unlike climate which is average of annual pattern, weather is annual variation that happens relative to climactic average.
what is temperature for cool, moderate, warm, and hot climates?
avg growing season temp:
cool: 16.5 or below
moderate: 16.5-18.5
warm: 18.5-21
hot: over 21
How is continental climate defined?
high continentality (big difference between coldest and hottest months)
short summers
large, rapid temp drop in autumn
risks: spring frost and low temperatures that affect flowering, fruit set and ripening. dry summers can necessitate irrigation
best varieties: bud late, ripen early
How is a maritime climate defined?
cool to moderate temperatures. low continentality. rainfall is evenly spread throughout year, moderates the temperature.
as a result temps are warm enough grapes to continue ripening into autumn
risks: rainfall in spring and summer can harm the flowering, fruit set and health of grapes at harvest
characteristics of Mediterranean climate?
low continentality. summers are warm and dry.
throughout Mediterranean and coastal CA, Chile, South Africa, South Eastern Australia are Mediterranean climates.
more warmth and sunlight than maritime. fuller bodied riper tannin, higher alcohol, lower acid.
risks: lower rainfall leads healthy grapes but also risk of drought.
