The Vine

Question 1

What are 2 vine species relevant to modern viticulture?

Answer 1

1. Vitis Vinifera
2. American Vines

Question 2

What species produces nearly all grapes used in wine making?

Answer 2

Vitis Vinifera

Question 3

What species are widely used to produce rootstocks (mainly) because of their resistance to Phylloxera?

Answer 3

American Vines

Question 4

What is Phylloxera?

Answer 4

An insect that feeds upon the root system of vine plants, leaving wounds that get infected and eventually kills the vine.

Question 5

How are American vines resistant to Phylloxera?

Answer 5

American vines defend themselves by producing a sticky sap clogging the mouth of Phylloxera and by releasing a protective layer behind the feeding wound that prevents further infections.

Question 6

Why American vines are rarely used to produce grapes for winemaking?

Answer 6

Because the grape they produce are widely considered to have unattractive flavors.

Question 7

What would a grower consider when selecting a grape variety rather than another when establishing a new vineyard?

Answer 7

-Local regulations
-Taste and quality of fruit
-Budding and ripening time matching the local climate
-Resistance to local disease pressure

Question 8

What are 2 techniques used in the propagation of vines?

Answer 8

• Cuttings
• Layering

Question 9

Why seeds are not suitable in propagation of vines?

Answer 9

Because each seed will produce a different grape variety which may have very different characteristics from its parent vine.

Question 10

Why are cuttings of Vitis Vinifera grafted on American rootstocks in nurseries before propagation in a vineyard?

Answer 10

Mainly because unlike Vitis Vinifera, American rootstocks are resistant to Phylloxera

Question 11

Why is layering not a suitable technique of propagation in vineyards where Phylloxera is present?

Answer 11

Because Vitis Vinifera is not resistant to Phylloxera

Question 12

Why are grapes produced from cuttings all similar in characteristics?

Answer 12

Because they have the same genetic material.

Question 13

What is a clone?

Answer 13

A clone is a vine that can be traced back to a single parent vine. It might have been selected for propagation through cuttings because of a slight desirable positive mutation.

Question 14

What is mutation?

Answer 14

Mutations may occur as a result of the plant adapting to its environment. Over time, the mutation may have such a significant effect that the plant is treated as a new variety. (Pinot Blanc and Pinot Gris are significant mutations of Pinot Noir)

Question 15

What is a natural Crossing?

Answer 15

A new variety produced by natural (wind-induced) cross-pollination of flowers from two parents of the same species : For example Cabernet Sauvignon is a natural cross between Cabernet Franc X Sauvignon Blanc. The seeds of grapes were later animal-dispersed and grown into new vines.

Question 16

What is a human bred Crossing?

Answer 16

A new variety produced in a research center by scientists looking to create a new variety for a specific purpose: For example, Müller-Thurgau is a cross between Riesling X Madeleine Royale. Pinotage is a cross between Pinot Noir & Cinsault.

Question 17

What is an hybrid?

Answer 17

A new vine from parents of different species: typically a cross between a Vitis Vinifera and an American Vine. These are typically used for rootstock production but not only (Vidal is an hybrid used for the production of grapes destined to wine production in Canada)

Question 18

Beside their resistance against Phylloxera, rootstocks have other useful characteristics…

Answer 18

• Resistance to nematodes (microscopic worms attacking root systems)
• Resistance against drought
• Adaptability to specific soils

Question 19

Name two wine provenances free of Phylloxera.

Answer 19

Chile & parts of Australia (thanks to a combination of factors such as isolation/ natural barriers and strict quarantine protocols)

Question 20

What is Grafting?

Answer 20

A general term for joining a rootstock to a vitis vinifera variety.

Question 21

Why would a grower use the technique of “head grafting” in an established vineyard?

Answer 21

To switch to a different grape variety between seasons. (Thereby saving time and costs of pulling out old vines and replanting new ones which would takes years to grow a viable crop)

Question 22

In a vine, what are 3 key functions of the root system?

Answer 22

1. Absorb nutrients & water from the soil
2. Anchor the vine in the ground
3. Store carbohydrates for winter survival

Question 23

In a vine, what is the main function of flowers?

Answer 23

Inflorescences are the reproductive organs of the vine

Question 24

In a vine, what is the main function of tendrils?

Answer 24

Tendrils grip on any supporting structure to help vine grow upward and find light.

Question 25

What is contained in a bud by the end of the growing season?

Answer 25

Buds contain in miniature all the structures that will become shoot, leaves, flowers and tendrils the following years.

Question 26

What is one-year-old wood?

Answer 26

A shoot that turned woody during the winter after it has grown. These are typically pruned to (short) spurs or a (long) canes depending on the number of buds left on them, which determines the crop for the following year.

Question 27

What is permanent wood on a vine?

Answer 27

More than one-year-old structures (trunk and sometimes arms) of the vine that remains after pruning every winter.