Chapter 1 - The Vine Flashcards
What is the main grape species used for wine production globally?
Vitis vinifera
What are the four most important North American vine species used as rootstocks?
- Vitis Labrusca
- Vitis Riparia
- Vitis Berlandieri
- Vitis Rupestris
What are the four main sections of vine structure?
- Shoots
- One-year-old wood
- Permanent wood
- Roots
What is the collective term for shoots and their major structures?
The canopy
What are the five major structures of vine shoots?
- Buds
- Leaves
- Tendrils
- Lateral shoots
- Inflorescences/grape bunches
What are nodes in vine anatomy?
The swellings along the shoot where other structures are attached
What are canes?
Lignified (woody rigid brown) shoots after leaves fall in late summer
What is the main function of tendrils?
To provide support by attaching to other plants/trees in the wild or trellising in cultivation
What happens during transpiration in vines?
Water diffuses from the leaf through stomata drawing water and nutrients from soil up through the vine
What are the two main types of buds in grapevines?
Compound buds (latent buds) and prompt buds
What is a compound bud and when does it grow?
A bud that forms in one growing season and breaks open in the next growing season
What are the components within a compound bud?
A primary bud (main growing point) and smaller secondary and tertiary buds
When do secondary and tertiary buds typically grow?
Only if damage has occurred to the primary bud (e.g. spring frost)
What is a prompt bud and when does it grow?
A bud that forms and breaks open in the same growing season producing lateral shoots
What is the main function of lateral shoots?
To allow the plant to continue growing if the primary shoot is damaged
Why might lateral shoots near the ends of primary shoots be beneficial?
They provide additional leaves for photosynthesis that can benefit from sunlight
Why might lateral shoots near the base of primary shoots be undesirable?
They impede air flow and can shade the fruit too much
What grape variety often forms inflorescences on lateral shoots?
Pinot Noir
What is the “second crop” in viticulture?
Inflorescences/bunches that form on lateral shoots which ripen later than those on the main stem
What are the three main components of a grape berry?
- Pulp
- Skin
- Seeds
Where are color compounds primarily located in grapes?
In the skin
What is the “bloom” on a grape?
A powdery waxy coating that covers the surface of the grape
What is a teinturier variety and what makes it unique?
A grape variety with red-colored pulp (most varieties have colorless pulp) e.g. Alicante Bouschet
What are the two main methods of vine propagation in modern viticulture?
Cuttings and layering
Why is propagation by cuttings the most common technique?
Many small cuttings can be taken from a vine simultaneously and it permits the use of rootstocks
What is the layering method of propagation?
Bending a cane down burying part of it in the ground until it roots then cutting it from the parent vine
Why might layering be unsuitable in some situations?
The new vine grows on its own roots with no protection against phylloxera and no benefits of selected rootstocks
What is clonal selection in viticulture?
Selecting vines with favorable characteristics for propagation by cuttings
How do the different clones of the same grape variety differ?
They have slightly different characteristics (grape size, skin thickness, disease resistance etc.)
Give an example of how Pinot Noir clones differ in their characteristics.
Clone 115 has low yields of small grapes (suited for quality red wine)
Clone 521 has higher yields of bigger grapes (better for sparkling wine)
What is mass selection (Sélection Massale)?
Taking cuttings from several different vines in one’s own vineyard typically the best-performing ones
What are the advantages of mass selection?
Increases diversity in the vineyard and uses unique planting material that can enhance quality/yield
What structures are considered “permanent wood” in a vine?
Woody parts older than one year including the trunk and cordons
What are cordons in vine structure?
Horizontal arms of permanent wood extending from the trunk
What are the three main functions of permanent wood (trunk and cordons)?
- Provide support
- Transport water and solutes
- Store carbohydrates and nutrients
Where are most of a vine’s roots found in the soil?
In the top 50 cm though they can reach over six meters down
What four factors influence root distribution in vines?
- Soil properties
- Irrigation
- Cultivation
- Rootstock type
Where does water and nutrient absorption occur in vine roots?
At the root tips where roots are actively growing
What do roots produce beyond their anchoring and uptake functions?
Hormones that have important functions in vine growth and grape ripening
Why is it beneficial to buy young vines from nurseries?
They’ve been tested to be free from virus infection
What is a disadvantage of having uniform clones throughout a vineyard or region?
Less diversity in fruit (potentially less complexity) and increased susceptibility to disease
What is a disadvantage of mass selection (Sélection Massale)?
If parent vines are infected with disease it can spread to new vines
Why is the monitoring and selection process in mass selection considered costly?
It requires time and labor to identify the best vines over several years
What happens to green shoots in late summer?
They lignify (become woody rigid and brown) and are called canes
What are stomata in vine leaves and what is their function?
Pores on the underside of leaves that allow water to diffuse out and carbon dioxide to enter
What happens to stomata when a vine is water stressed?
They partially close conserving water but limiting photosynthesis
What typically happens to lateral shoots during summer pruning?
They may be removed especially those near the base that impede air flow
How are new grape varieties typically produced?
From seeds resulting from cross fertilization between two vines
What is the difference between a “cross” and a “hybrid” in grape breeding?
A cross is between two vines of the same species; a hybrid is between different species
What is an example of a cross and how was it created?
Pinotage a cross of Pinot Noir and Cinsaut
What is an example of a hybrid used in wine production?
Vidal Blanc from Ugni Blanc (V. vinifera) and a member of the Seibel family (American parentage)
How was Cabernet Sauvignon likely created?
Through chance cross fertilization of Sauvignon Blanc and Cabernet Franc
How can mutations lead to new grape varieties?
Significant mutations in the genetic code can create vines classified as new varieties
What four grape varieties are mutations of the original Pinot variety?
- Pinot Noir
- Pinot Meunier
- Pinot Blanc
- Pinot Gris
What modern technique has sped up vine breeding programs?
Using genetic markers to select offspring with desired characteristics
How does the “second crop” from lateral shoots differ from the main crop?
- Higher acidity
- Lower sugar
- Potentially unripe tannins and aromas/flavors
- Less color development in black grapes
What is green harvesting in relation to the second crop?
Removing the second crop during the growing season to enhance ripening of remaining bunches
Why is the second crop an issue with machine harvesting but not hand harvesting?
Hand harvesting allows for selection; machine harvesting takes everything and can affect must quality
Which grape variety is noted for having tight bunches and being more prone to fungal diseases?
Pinot Noir
Why are tight bunches more susceptible to fungal diseases?
Increased likelihood of grape-skin splitting and lack of air flow through the bunch
Where are tannins primarily located in a grape?
In the skin and seeds
What part of the grape contains the highest concentration of aroma compounds?
The skin
