The Vine and Growing Environment Flashcards
American Vine Names
Vitis Lambrusca
Vitis Riparia
Vitis Berlandieri
Vitis Rupestris
Prompt Buds
Form and break in the same season
Compound buds
Produce main shoots the next growing season (Primary + Secondary/Tertiary as backup)
Grapes with red pulp are called
Teinturier (e.g. Alicante Bouschet)
What compounds make up the seeds of a grape
The seeds are yellow -> dark brown as the grape matures. Made up of:
- Oils
- Tannins
- Embryo
Where are carbohydrates (starch) stored in the vine
- One year old wood,
- Permanent wood
- Roots.
What function do roots serve
- Anchor the vine
- Uptake water and nutrients (from tips)
- Store carbohydrates
- Product hormones
What determines the distribution of vine roots
- Soil properties
- Irrigation
- Cultivation
- Rootstock
What is the difference between a cross and a hybrid
Cross - parents the same species (Pinotage = Pinot Noir x Cinsault)
Hybrid - parents different species (Vidal Blanc = Ugni Blanc x Siebel non vinifera)
What grapes were crossed to make Muller Thurgau
Reisling (fruit quality) x Madeline Royale (yield).
Describe the wild grape growth cycle
Grow in woodlands and forests, climb up trees looking for sunlight, once they reach the canopy top, they flower and produce fruit. Rely on birds to distribute seeds.
What are the basic needs of a grape vine
- Water
- Sunlight
- Warmth - photosynthesis
- Nutrients (limited)
- Carbon Dioxide (not usually a limiting factor)
What factors influence budburst
- Mild winter days - encourage early budburst
- Soil - higher soil temp = early (soil composition also important)
- Grape Variety - early/late budding. early = burst at slightly lower temp (just below 10C).
- Human Factors - viticulture can advance/delay
How is budburst delayed and why
- Winter pruning during dormancy.
- Frost is a threat.
What nutrients are needed at ‘Shoot and Leaf Growth’ stage of the cycle
- Nitrogen
- Potassium
- Phosphorus
Petiole
Stalk that joins a leaf to a stem. Buds develop at the base.
Stages of pollination
- Pollination - Stamen sheds pollen grains. Land on moistened stigma.
- Germination - Each grain produces a pollen tube.
- Fertilisation - Pollen tubes penetrate stigma then ovule. Delivers sperm which fertilises the egg. Grape berry forms.
- Seed formation - Seeds form in fertilised ovules (<=4 per grape)
- Ovary enlarges - Forms skin + pulp of grape.
Coulure
Fruit set fails in high proportion of flowers (<30% is normal)
Caused by:
- Imbalance in carbohydrate levels
- Low photosynthesis,
- Cold, Cloudy conditions (Bordeaux)
- Shoot growth too strong diverting carbs from inflorescence (vine balance)
Millerandage
Seedless grapes.
Can ripen normally but smaller = reduced yield.
Some stay green + small (wine quality).
Difference between Xylem and Phloem
- Xylem transports water and carbohydrates from roots. Made up of dead (lignified tissue)
- Phloem transports sugar (produced by photosynthesis) and water from the leaves to other parts of the vine.
- Initially Xylem is used, after veraison and during ripening the Phloem is responsible for over 80% of transfer and the function of the Xylem becomes negligible.
https: //www.ncbi.nlm.nih.gov/pmc/articles/PMC2773088/