Ch 2 The Vine Growth Cycle Flashcards
What is the purpose of grapes
Animals and birds eat and spread seeds
What are the main processes/functions of the vine and what do they need?
- light, warmth, water + C02 (out of WM control) -for photosynthesis
2.warmth for respiration (energy is released in form of sugar) - Nutrients - for cell and vine function/growth
What are the phases of vine growth and when do they occur?
Leaf fall/Dormancy: Nov - Mar/May-Sep
Budburst: Mar-Apr/Sep-Oct
Leaf and shoot growth: Mar - June/Sep -Dec
Flowering and fruitset: May-June/Nov-Dec
Grape development: June - Sept/Dec-Mar
Harvest: Aug - Oct/Feb-Apr
Remember 5-4-4-3 (with first 4 having 2 sub phases)
Dormancy
When is dormancy and what condition triggers it
North: Nov - Mar
South: May - Sep
Triggered by avg air temps below 10°C
Dormancy
What happens in dormancy?
Leaves fall in autumn
Photosynth stops - vine sustains on energy (carbs in form of starches) stored in growing season in roots, trunk and branches
Dormancy
What are the main advserse conditions and impacts of dormancy?
Extreme cold
<-20°C - can damage or kill vine
<-25°C kills most vitis vinfera vines
Dormancy
What human activities occur?
Winter pruning
Budburst
What is budburst, when does budburst happen and what are vines’ main needs?
When compound buds from prior season burst open
North: Mar-Apr/South: Sep/Oct
Needs - avg air temp above 10°C
Budburst
What factors influence timing of budburst
- Air temp - over 10°C
- Soil temp- high temp=earlier budburst
- Grape var -
- Human factors - prior season pruning and vine growth
Budburst
What role do different climate classifications have on budburst - advantage in areas with larger seasonal temp differences?
Areas with clear differences in seasonal temps (continental) have advantage - more uniform budburst -> more uniformity in other phases and even in ripeness
- places with less difference - budburst less synchronized
Budburst
What can cause early budburst and what is the risk/implication?
Even a few days of warm temps in winter - early budburst can be damaged by frost –> lowers yields
Budburst
What role does soil temp play in budburst and where is it helpful?
Warmer soil = earlier budburst
Dry, free draining soils warm faster/retain warmth better than water-storing soils –>
* helpful in cool climates by starting growing season earlier
Budburst
What role does grape variety play in timing of budburst; examples of early/late budding varieties?
Different varieties need diff min average temps for budburst
Early: - burst at lower avg temps – PN, Chard, Mer, Grenache
Late: - need higher avg temps – SB, CS, Syr –> less risk of frost damage
Budburst
What human factors can influence timing of budburst?
Later winter pruning can postpone budburst - use in areas where frost is an issue
Budburst
Name 4 early budding varieties
Name 3 late budding varieites
Early:
* Chardonnay
* Pinot Noir
* Merlot
* Grenache
Late:
* Sauv Blanc
* Cab Sauv
* Syrah
What is transpiration and what is respiration?
Transpiration is process of drawing water and minerals from roots which is transported thru the vine to the leaves
Respiration is the process of leaves absorbing C02 and giving off oxygen and glucose (Photosynthesis)
Shoot and leaf growth
When is shoot and leaf growth, what is it and what are vines main needs?
When - mar - june (north); Sept- Dec (south)
What is it -shoots continue to grow; leaves and inflorescences mature; fastest growth bet budburst and flowering
* most of vine energy toward shoot growth until flowering
What vine needs - stored carbs, warmth, sunlight, nutrients and water
Shoot and leaf growth
What are adverse conditions and implications?
Low carb levels - from prior season
Water stress
Stunted shoot growth
Shoot and leaf growth
What does vigor mean and what are the implications?
What are the factors that influence vigor?
VIgor is vegetative growth of the vine - shoots, leaves, and lateral shoots
* implications - yield and ripening of grapes
* High vigor - long shoots with large leaves and lots of lateral shoots
Factors that influence:
* Natural resource avail - water,nutrients, temps
* Planting material - rootstock, variety, clone
* Human factors - canopy management choices
Shoot and leaf growth
What are vine needs and energy sources in this phase?
Carbs - stored in trunk and branches -> support initial shoot growth
Leaves - photosynth - need warmth and sun
Nutrients - Potassium, Nitrogen, phosphorus
Water
Shoot and leaf growth
What can cause low carb levels in vine and the implications?
What impact do low water levels have?
What is impact of stunted shoot growth?
Implications of adverse conditions
Low carb causes
Prior season - excessive yields, excessive pruning
This season - excess leaf removal, water stress, mildew infections
Low water impact:
* limited photosynth and shoot growth
* nutrient uptake inhibited by dry soil
Stunted shoot growth impact
* small, weak shoots -> dont flower properly, grape bunches dont fully ripen = poor quality and yields
Flowering and Fruit Set
When, what happens in this phase and what are vines main needs?
When - May-June (north); Nov-Dec (south)
Prompt buds burst and create lateral shoots for this years growth (new compound buds form for next yr)
Needs - warm temps min 17°C and sun/warmth/water/nutrients for bud fruitfulness
Flowering and Fruit Set
What is bud fruitfulness and what impacts it?
Fruitfulness = flowering potential of next yr compound bud
Things that impact following years harvest on # of flowers and yields
* shading of the compound bud
* temps that are consistnetly <25°C
* water stress
* nutrient deficiency
