1. The Vine

Question 1

What are the four most important North American species of vine?

Answer 1

1. Vitis Lambrusca
2. Vitis Riparia
3. Vitis Berlandieri
4. Vitis Rupestris

Question 2

What is the role of the main axis of the shoot?

Answer 2

The main axis of the shoot transports water and solutes to and from the different structures (solutes are substances that dissolve in a liquid to form a solution and in this instance include sugars and minerals). It is also a store of carbohydrates.

Question 3

What are nodes?

Answer 3

The little swellings along the shoot, where the other structures are attached, are called nodes. The lengths in between the nodes are called internodes.

Question 4

What are canes?

Answer 4

In late summer, the leaves fall from the vine and the green shoots lignify (become woody, rigid and brown); from this point they are called canes.

Question 5

Where do buds form?

Answer 5

Buds form between the leaf stalk (petiole) and the stem.

Question 6

What are compound buds?

Answer 6

Compound buds (also called latent buds) form in one growing season and break open in the next growing season (provided they are retained during winter pruning). They produce the shoots in the next growing season.

Question 7

What do the compound buds consist of?

Answer 7

Within a compound bud, there is typically a primary bud (the main growing point) and smaller secondary and tertiary buds. The secondary and tertiary buds usually only grow if damage has occurred to the primary bud (e.g. spring frost).

Question 8

What are prompt buds?

Answer 8

Prompt buds form and break open in the same growing season. They form on the primary shoot (that has just grown from a compound bud) and produce lateral shoots.

Question 9

What are lateral shoots?

Answer 9

Lateral shoots grow from buds formed in the current year (prompt buds). They are smaller and thinner than the primary shoots. Lateral shoots have a stem, leaves, buds, tendrils and sometimes inflorescences.

Question 10

What is the main role of lateral shoots?

Answer 10

Their main function is to allow the plant to carry on growing if the tip of the primary shoot has been damaged or eaten.
Lateral shoots can provide an additional source of leaves for photosynthesis, which can be useful if the laterals are near the ends of the primary shoots and able to benefit from sunlight.

Question 11

When are lateral shoots undesirable?

Answer 11

Growth of laterals nearer the base of the primary shoot can be undesirable as they impede air flow and can shade the fruit too much. They may be removed in summer pruning.

Question 12

What are the characteristics of a second crop?

Answer 12

If harvested at the same time as the main crop, the bunches in the second crop will be higher in acidity, lower in sugar and may have unripe tannins and aromas/flavours and, in black grapes, less colour development.

Question 13

What is green harvesting thought to achieve?

Answer 13

This technique is thought to enhance the ripening process and improve the uniformity of ripeness of the remaining bunches.

Question 14

Describe the photosynthesis process of the vine.

Answer 14

Stomata (pores) open on the underside of the leaves, letting water diffuse out and carbon dioxide for photosynthesis to enter. As water diffuses from the leaf, a process called transpiration draws water and nutrients from the soil up through the vine to the leaves.

Question 15

What happens when the vine is water stressed?

Answer 15

The stomata partially close if the vine is water-stressed. This can help conserve water, but limits photosynthesis by preventing carbon dioxide from entering the vine.

Question 16

How many inflorescences develop on each shoot?

Answer 16

Depends on grape variety, but usually between one and three.

Question 17

What does a grape’s pulp contain?

Answer 17

It contains water, sugars, acids and some aroma compounds and aroma precursors.

Question 18

What are teinturier varieties?

Answer 18

Rare varieties with red coloured pulp.

Question 19

What does a grape’s skin contain?

Answer 19

A high concentration of aroma compounds and aroma precursors, tannins and colour compounds. The amount of tannins and colour in black grapes is significantly higher than in white grapes.

Question 20

What does a grape’s seeds contain?

Answer 20

Seeds contain oils, tannins and the embryo, which can grow into a new plant.

Question 21

What is one-year-old wood?

Answer 21

The shoots from the previous growing season that were not removed at pruning and have lignified.
Will be pruned to be a cane or spur.

Question 22

What is permanent wood?

Answer 22

These are the woody parts of the vine that are older than one year, including the trunk and sometimes cordons.

Question 23

To what depth do a vine’s roots typically reach?

Answer 23

Most of the vine’s roots are found in the top 50 cm of the soil, although vine roots have been found that reach over six metres down into the soi

Question 24

What factors influence the framework of a vine’s roots?

Answer 24

Distribution of the main framework of roots is influenced by the soil properties, irrigation, cultivation and the type of rootstock.

Question 25

What do the vine’s roots do?

Answer 25

The roots are important for anchoring the vine and also for the uptake of water and nutrients.

Question 26

What is cutting?

Answer 26

A cutting is a section of a vine shoot that can be planted and will then grow as a new plant.

Question 27

Why is cutting the most common technique used for vine propagation?

Answer 27

Many small cuttings can be taken from a vine and propagated at the same time.
Permits the use of rootstocks, onto which the vine cutting can be grafted before it is planted.
Nurseries are able to treat vine cuttings to avoid spread of diseases.

Question 28

What is layering?

Answer 28

Layering is a method of filling gaps in a vineyard by using shoots from an established neighbouring vine to produce a new vine.
A cane is bent down and a section of it is buried in the ground. The tip of the cane points up out of the ground. The section that is buried takes root and, once these roots are established, the cane linking the new growth to the original plant is cut.

Question 29

Why is layering not suitable for many vineyards?

Answer 29

The new vine grows on its own roots, not those
of a rootstock, and this method is therefore not always suitable. The new vine will have no protection against phylloxera or have the qualities (such as the desired yield) that a choice of rootstocks offers.

Question 30

Why are vines not propagated through seeds?

Answer 30

Vines that grow through seeds are not genetically identical to the parent vines and although they can show similar characteristics to their parents, more often they are notably different.

Question 31

What is clonal selection?

Answer 31

Vines with particularly favourable characteristics are selected by vine nurseries or grape growers for propagation by cuttings in order to grow new vines with these favourable characteristics.

Question 32

Give two examples of Pinot Noir clones and their characteristics.

Answer 32

Pinot Noir Clone 115 has low yields of small grapes, making it suited to high quality red wine production.

Pinot Noir Clone 521 has higher yields of bigger grapes, making it better suited to sparkling wine production. This is because high concentrations of tannins and colour from the skins are not needed in these wines.

Question 33

What are the disadvantages of growing the same clone through a vineyard or region?

Answer 33

There is less diversity
in the fruit and hence potentially producing a wine with less complexity and balance (if that is desired for the style and quality of the wine).
It also makes the vineyard more susceptible to disease (the identical vines are likely to all be equally susceptible to a disease or pest).

For these reasons, where available, a grape grower will often buy and plant a number of different clones of the same grape variety.

Question 34

What is mass selection?

Answer 34

The technique requires vineyard owners to take cuttings from the vines in their own vineyard(s) and cultivate them.

Question 35

What are the advantages of mass selection?

Answer 35

Increases the diversity of planting material in the vineyard and throughout the region.
The vineyard owner is using their own unique planting material (different from that being bought from the local nursery), which can enhance fruit quality and/or yield (and can be used as a marketing asset).

Question 36

What are the disadvantages of mass selection?

Answer 36

The selection and monitoring of vines to ensure the propagation of the best vines is costly in terms of time and labour.
I the parent vine is infected by disease (e.g. a virus), this is likely to be passed onto the new vines, and therefore this technique can increase the spread of vine diseases.

Question 37

What is cross fertilisation?

Answer 37

The pollen from the stamens of the flowers of one vine is transferred to the stigmas of the flowers of another vine and fertilisation occurs

Question 38

How are new grape varieties produced?

Answer 38

Grapes develop from cross fertilisation and the seeds from these vines are planted and grown.
If plant shows desirable characteristics, it may be propagated by cuttings to create identical vines.

Question 39

What is the OIV catalogue?

Answer 39

International Organisation of Vine and Wine (OIV).
Catalogue of all registered, commercially produced grape varieties.

Question 40

What is a cross?

Answer 40

When the two parent vines of a new grape variety are from the same species.
For example Pinotage (Pinot Noir x Cinsault).

Question 41

What is a hybrid?

Answer 41

When the two parent vines of a new grape variety are from different species.
For example Vidal Blanc (Ugni Blanc, Vitis Vinifera x a member of the Siebel family).

Question 42

What is the main reason new grape varieties rarely come to the market?

Answer 42

Consumer resistance