Chapter 1.2: Vine Propagation

Question 1

Define and describe shoots

Answer 1

Shoots are the green stem structures that leaves are attached to on the grapevine.

They begin growing at budburst from buds retained from the previous year and are made up of buds, leaves, tendrils, lateral shoots, and inflorescenes (grape bunches).

The main axis of the shoot transports water and solutes to and from different structures and includes a store of carbohydrates.

Question 2

Define and describe one-year-old wood

Answer 2

One-year-old wood refers to the primary shoots from the previous growing season that were not removed at pruning and have lignified. They are either canes or spurs, depending on how they were pruned.

One-year-old wood supports the compound buds that will break to release the shoots for the upcoming growing season.

Question 3

Define and describe permanent wood

Answer 3

Permanent wood is the woody parts of the vine that are older than one year, including the trunk and, for some, cordons.

• Provides support to other parts of the vine
• Transports water and solutes to and from different parts of the vine
• Stores carbohydrates and nutrients

Question 4

What are the main functions of a grapevine’s roots?

Answer 4

Main functions are to (1) anchor the vine, (2) uptake water, (3) store carbohydrates, and (4) produce hormones that have important functions within vine growth and grape ripening.

Question 5

Describe the buds of a grapevine

Answer 5

Buds contain all the structures in miniature that will become green parts of the vine (stem, buds, tendrils, leaves, and often inflorescences).

They are formed between the petiole (leaf stalk) and the stem.

There are two types: compound (latent) buds and prompt buds.

Question 6

Define and describe compound buds

Answer 6

Compound buds form in one growing season and break open in the next growing season (so long as retain during winter pruning), producing the shoots in the next growing season.

Compounds buds contain a primary bud (the primary growing point) and smaller secondary and tertiary buds which only grow if damage has occurred to the primary bud, e.g., spring frost.

Question 7

Define and describe prompt buds

Answer 7

Prompt buds form and break open in the same growing season.

They form on the primary shoot (the one that just grew from the compound bud) and produce lateral shoots.

Question 8

Define and describe lateral shoots

Answer 8

Lateral shoots grow from prompt buds and are smaller and thinner than primary shoots.

Primary function is to allow the grapevine to continue growing if the tip of the primary shoot has been damaged or eaten.

Question 9

Define and describe tendrils

Answer 9

Tendrils are a green part of the grapevine that help the vine attach itself to support structures, including trellis wires; however, grape growers don’t trust the tendrils to keep the canopy in place and hold the vine to a trellis and will often tie in canes and shoots as necessary.

Question 10

Define and describe leaves

Answer 10

Leaves are the main site of photosynthesis for the grape vine and critical to the production of sugars needed for vine growth and metabolism.

Question 11

Define transpiration

Answer 11

Transpiration is the process of drawing water and nutrients from the soil up through the vine to the leaves as water diffuses from the leaf.

Question 12

Define inflorescences

Answer 12

Inflorescences is a cluster of flowers on a stem, which becomes a bunch of grapes at fruit set.

Although the number on each primary shoot depends on the variety, there are generally between one and three.

Question 13

Describe the pulp of a grape

Answer 13

• Pulp makes up the majority of the grape’s weight and volume.
• Pulp contains water, sugars, acids, and some aroma compounds and aroma precurors (thiols, terepenes).
• Most pulp is colorless; however, teinturier varieties of grapes, e.g., Alicante Bouschet, have red-colored pulp.

Question 14

What does the skin of a grape contain?

Answer 14

• high concentration of aroma compounds and aroma precursors
• tannins
• color compounds

Question 15

Describe the seeds of a grape

Answer 15

• Mature inside the grape, turning yellow to brown
• Contain oils, tannins, and an embryo that can grow into a new plant

Question 16

Define cordons

Answer 16

Cordons are one or more horizontal arms of permanent wood.

Question 17

What are the four anatomical structures of the vine?

Answer 17

Main shoots
One-year-old wood
Permanent wood
Roots

Question 18

What are the parts that collectively make up the canopy?

Answer 18

• Stem
• Buds
• Leaves
• Lateral Shoots
• Tendrils
• Inflorescences/Bunches of grapes

All are structures of the main shoots

Question 19

In the spring, the main shoots of a vine grow from ____ retained from the previous year.

Answer 19

Buds (Compound Buds)

Question 20

What role does the main axis of the shoot have in regards to how a vine functions?

Answer 20

• Transports water and solutes to and from the various vine structures.
• Stores carbohydrates

Question 21

What are solutes?

Answer 21

Sugars and minerals – substances that dissolve in liquid to form a solution

Question 22

What is the difference between a node and an internode?

Answer 22

• Node - swelling on the stem where other structures of the vine are attached
• Internode - area, or distance, between nodes

Question 23

What does it mean when shoots lignify?

Answer 23

When green shoots turn brown and become woody and rigid.
Once this happens, that shoot is then referred to as a cane.

Question 24

Where do buds form on the vine?

Answer 24

Between the leaf stalk (petiole) and the stem.

Question 25

What are buds made of?

Answer 25

Buds become all the green parts of the vine – stem, buds, tendrils, leaves, inflorescences

Question 26

What are the two main types of buds?

Answer 26

Compound (latent) buds Prompt buds

Question 27

What is the main difference between compound buds and latent buds?

Answer 27

* Compound buds form in one growing season and break open in the next growing season * Prompt buds form and break open in the same growing season

Question 28

What do compound buds produce? Briefly describe what is inside a compound bud.

Answer 28

Compound buds produce the main shoots in the next growing season. Inside a compound bud there is a primary bud (the main growing point) and small secondary and tertiary buds, which generally only grow if the primary bud has suffered damage, e.g., spring frost

Question 29

What do prompt buds produce?

Answer 29

Lateral shoots

Question 30

On what do prompt buds grow?

Answer 30

Grow on the main shoot which has just grown from a compound bud

Question 31

What structures do lateral shoots have?

Answer 31

Stem, leaves, buds, tendrils, sometimes inflorescences

Question 32

What is the main function of lateral shoots?

Answer 32

to allow the vine to continue growing if the tip of the main shoot has been damaged or eaten; they're especially helpful being an additional source of photosynthesis

Question 33

Why is it undesirable to have lateral shoots near the base of the main shoot?

Answer 33

They can impede air flow and shade the fruit too much. They are usually removed during summer pruning.

Question 34

What are the benefits of keeping the inflorescences on lateral shoots and letting them develop into clusters (also known as a second crop)?

Answer 34

* If they grow into clusters and are green harvested, their removal is thought to improve the ripening process and enhance the uniformity of ripeness of the remaining bunches * If they grow into clusters and are hand-harvested, the vineyard manager can be selective and either give them a longer hang time or the clusters can be separated

Question 35

What is the profile of bunches from a 'second crop' harvested at the same time as the main crop?

Answer 35

* Higher in acidity * Lower in potential alcohol * Potentially unripe tannins, aromas, and flavors * In black grapes, the bunches will have less color develoopment

Question 36

What role do the tendrils have?

Answer 36

* Provide support for the vine * Help position the vine canopy * Help keep canopy in place

Question 37

What are stomata

Answer 37

* Pores on the underside of leaves that allow a plant to take in carbon dioxide, which is needed for photosynthesis * Stomata also allow water vapor to diffuse out of the plant, but when conditions are hot or dry, they can close to reduce water loss, but that limits photosynthesis by preventing carbon dioxide from entering the vine

Question 38

Where in the vine does photosynthesis mainly happen?

Answer 38

Leaves

Question 39

What is inflorescence?

Answer 39

A cluster of flowers on a stem which, when fertilized, develops into a bunch of grapes at fruit set.

Question 40

How many inflorescences develop on each main shoot?

Answer 40

Between one and three, depending on the grape variety

Question 41

What are the three main parts of a grape?

Answer 41

* Pulp * Skin * Seeds

Question 42

What is a teinturier grape variety?

Answer 42

One that has red-colored pulp, as opposed to the majority of grape pulp that is colorless. Alicante Bouschet

Question 43

What does grape pulp consist of?

Answer 43

* Water * Sugars * Acids * Some aroma compounds and aroma precursors

Question 44

What does grape skin consist of?

Answer 44

* High concentration of aroma compounds and aroma precursors * Tannins * Color compounds

Question 45

What do seeds consist of?

Answer 45

* Oils * Tannins * Embryo, which can grow into a new plant

Question 46

As seeds mature, their color goes from __ to __

Answer 46

Yellow to dark brown

Question 47

What is the powdery, waxy coating on grapes called?

Answer 47

Bloom

Question 48

What does 'one-year-old' wood refer to?

Answer 48

The main shoots from the last growing season that were kept at pruning.

Question 49

What is the most important function of one-year-old wood?

Answer 49

It has the compound buds that will release the main shoots for the upcoming growing season.

Question 50

One-year-old wood will either be called a __ or a __, depending on how the vine was pruned.

Answer 50

Cane or a spur

Question 51

Any of the woody parts of the vine, including the trunk, that are older than one year are called __

Answer 51

Permanent wood

Question 52

What are cordons?

Answer 52

Horizontal 'arms' of a vine made of permanent wood

Question 53

What functions do the roots of a vine have?

Answer 53

* Anchor the vine to the soil * Uptake water and nutrients * Store carbohydrates * Produce hormones for growth and ripening

Question 54

Where are the vine's roots found?

Answer 54

Mostly in the top 50 cm of the soil, although have been found to reach over six meters down into the soil

Question 55

How are vines propagated in today's viticulture?

Answer 55

Cuttings or layering

Question 56

What is a cutting?

Answer 56

Section of a vine shoot that is planted which then grows as a new plant

Question 57

What is layering and how is it done?

Answer 57

Using a shoot from an established, neighboring vine to produce a new vine. Shoot is bent down and a section of it is buried in the ground with the tip of it pointing up out of the ground. The buried part of the shoot takes root. Once the new roots are established, the cane linking the new growth to the original plant is cut. The new vine grows on its own roots, not those of a rootstock, which can be problematic in that the new roots don't offer any kind of resistance to phylloxera.

Question 58

Why is layering done?

Answer 58

To fill in gaps in the vineyard, like when a vine is pulled or dies

Question 59

Cutting and layering generally produce that that are (a) genetically identical or (b) completely different from the parent vine.

Answer 59

Genetically identical

Question 60

During plant growth, random mutations in the genetic code of a vine create __

Answer 60

Clones

Question 61

What is clonal selection?

Answer 61

When vine nurseries or grape growers propagate a vine that has somewhat different but desirable characteristics, or mutation, by using cuttings from that vine to grow new vines which will then have the same desirable and somewhat different characteristics (mutations). Some clones have mutations such as higher yields, bigger or smaller grapes, and varying tannin levels, all of which can be applied to the needs of the grape grower and what style of wine they produce.

Question 62

Why would a grape grower plant a number of different clones of the same grape variety rather than planting vines that are all the same clone?

Answer 62

to increase diversity in the vineyard to make the vineyard less susceptible to disease

Question 63

What is Mass Selection?

Answer 63

Term used to describe a traditional method of vineyard propagation. Grape growers make a selection of particular vines within an old vineyard and use this subset as the genetic stock to plant a new vineyard. Vines selected for propagation have attributes that are important to the producer, whether that be yield, hardiness or sensory qualities.

Question 64

What is a major downside of Mass Selection?

Answer 64

If the parent vine carries any disease, that disease will be passed down to the new vines through its cuttings, increasing the spread of the disease.

Question 65

Describe the difference between Mass Selection and Clonal Selection

Answer 65

Mass selection is the old way - done 'at home' in the vineyard - and clonal selection is done deliberately at a grapevine nursery. Both methods have their supports and opponents, but many believe that mass selection preserves more diversity in the vineyard. With mass selection, a grower selected the vines from their vineyards that exhibit more desirable attributes and use cuttings from these to plant new vines. So while these selected vines produce the finest fruit they not are not necessarily identical. Clonal selection takes mass selection to a deeper level, where better vines are selected for propagation again and again until there is a more precise vine that can be replicated at the nursery, be officially recognized, registered and made available for sale from the nursery. Clones are identical to their parent. The idea of clonal selection is to have an army of the same vine showing the same characteristic(s).

Question 66

Generally, new grape varieties are produced from (a) roots, (b) seeds, or (c) cuttings

Answer 66

Seeds

Question 67

What are the steps a grower would take to create a new grape variety?

Answer 67

Cross fertilize two vines (pollen from the flowers of one vine is transferred to the stigmas of the flowers of another vine) Plant the seeds from this new plant and grow new vines; These new vines that grow from the seeds will all have different characteristics, and if one of the new vines has desirable characteristics it may be propagated by cuttings to create identical vines

Question 68

What is the difference between a cross and a hybrid?

Answer 68

A cross is a plant offspring that has two parent vines from the same species. A hybrid is a plant offspring that has two parent vines from different species

Question 69

What are the differing aims of creating and breeding crosses and hybrids?

Answer 69

The aim of creating and breeding a cross is usually to create an offspring that has favorable characteristics of the two parent vines; The aim of creating and breeding a hybrid is usually to create an offspring that combines the resistance of non-vinifera species (to diseases, pests or climatic extremes) and the quality of fruit from V. vinifera

Question 70

List the four sections of the vine

Answer 70

Primary Shoots, One-Year-Wood, Permanent Wood, Roots

Question 71

List the parts of the Canopy

Answer 71

Stem (Xylem & Phloem), Buds (Compound & Prompt), Lateral Shoots, Tendrils, Leaves, Inflorescences, Berries