C4 - The Vine - Micky - completed Flashcards
What are the most important species in modern viticulture?
- Vitis vinifera
- American vines
Which vine species produces nearly all the grapes used in winemaking?
Vitis vinifera
Why are American vines rarely used to produce grapes for winemaking?
Their grapes are widely considered to have unattractive flavours
Why are American grapevine species important?
They are resistant to Phylloxera and consequently widely used to produce rootstocks onto which Vinifera vines are grafted
What are the principal differences between grape varieties?
Colour and flavour
What other factors may a grape grower be concerned with when selecting a grape variety?
- Budding and ripening times
- Resistance to certain diseases
Which two methods may a grower use to preserve the unique qualities of a grape variety?
Cutting
Layering
What is a cutting?
A section of a vine shoot that is planted and then grows as a new plant
Which method of growing new plants is most commonly used in commercial nurseries?
Cutting
Where does layering take place?
In the vineyard
Describe layering
A cane is bent down and a section of it is buried in the ground, the cane tip points upwards out of the ground.
The buried section takes root and when this happens, the linking cane is cut.
Which propagation method is more common? Why?
Cutting
Due to the risk of phylloxera
How can several plants be identified as one variety?
They can all trace their lineage back through a series of cuttings and/or layering to a single plant
What other term can be used for vine variety?
Grape variety
Which word can be used instead of variety?
Cultivar
Why may there still be variations between vines despite their being technically the same variety?
Mutations sometimes occur when the vines grow
Which vines are more likely to be selected for further propagation?
Those which have developed positive/beneficial mutations e.g. better quality fruit or better disease resistance
What is clonal selection?
Choosing individual vines with beneficial mutations for further propagation
Each individual vine or group of vines that shows a particular set of unique characteristics is known as a …
Clone
What will a grape grower often specify when ordering new plants from a nursery?
The clone as well as the variety
List two varieties which are the result of more extreme mutations from Pinot Noir?
Pinot Gris and Pinot Blanc
What is cross-fertilisation?
A method of creating a new variety under controlled conditions
Describe cross-fertilisation
Pollen from the male part of the flower of one vine is transferred to the female part of the flower of another vine and fertilisation occurs. The pollinated flowers develops into a grape with seeds. If the seed is planted and grows, it will be a new variety.
Can a grape’s characteristics be predicted when cross pollination occurs?
No, there is no way of knowing
Why is it costly and time-consuming to create a new variety for commercial use?
- Hundreds of seeds are required
- Many seedlings fail in the first year
- Producers must wait 2-3 years before the survivors flower and produce fruit
- It takes longer to prove the value of the new variety
How is a crossing defined?
A new variety which is produced from two parents of the same species
Examples of crossing
- Cabernet Sauvignon (Cab Franc x Sauvignon Blanc)
- Muller Thurgau (Riesling x Ma deleine Royale)
- Pinotage (Pinot Noir x Cinsault)
*technically every grape varieties used today is a crossing.
What is a hybrid?
A vine whose parents come from two different vine species, typically American vine is one of the parents.
What are hybrids and American vine crossings most commonly used for?
Rootstocks
What is Phylloxera?
An insect that is native to North America which Vinifera is unable to defend itself against
What caused wholesale destruction of European vineyards in the nineteenth century?
Phylloxera when it was accidentally introduced to Europe
…has a very complex lifecycle
Phylloxera
What is the most harmful phase of Phylloxera’s lifecycle to a vine? What happens?
When it lives underground and feeds on the roots of the vine. Infection enters through the feeding wound, weakening and eventually killing the vine.
How do American varieties protect themselves against Phylloxera?
They clog its mouth with a sticky sap and form a protective layer behind the feeding wounds to prevent secondary infection
Strict quarantine procedures have successfully protected which areas against Phylloxera?
Chile, parts of Argentina and South Australia
What was the only protection against Phylloxera when it first hit Europe?
American species or hybrids
What was the better, but more expensive solution to Phylloxera which was found at the end of the 19th century?
Using American vines/hybrids as rootstocks
Give two other advantages of some rootstocks, other than resistance to Phylloxera
- Protection against Nematodes
- Drought resistance
What is grafting?
It is the technique used to join a rootstock to a Vinifera variety
What is the most popular modern grafting technique?
Bench grafting
What does bench grafting involve?
Short sections of cane from both varieties are joined together by machine and stored in a warm environment to encourage fusion
What is the less common type of grafting?
Head grafting
When is head grafting used?
When a grape grower with an established vineyard decides to switch to different variety between seasons
How is head grafting performed?
- The existing vine is cut back to its trunk
- A bud or cutting of the new variety is grafted onto the trunk
What are the biggest advantages of head grafting?
- The vine will produce the fruit of the new variety at the next vintage (much quicker)
- It’s much cheaper than replanting a whole vineyard
What can be used to protect a graft join?
Wax
What are leaves principally responsible for?
Photosynthesis
Summarise photosynthesis
The process by which plants use sunlight to convert water and carbon dioxide into glucose and oxygen
Describe buds
- Form in the join between the leaf and the shoot
- They mature inside their casing, so that eventually they contain miniature all the structures that will become the shoot, leaves, flowers and tendrils
Describe tendrils
Tendrils allow the vine to support itself by wrapping around a structure
What are flowers?
- The reproductive organs of the vine
- It has male and female parts
- It’s grouped in bunches called inflorescences
Describe berries
- Each flower that is successfully pollinated, becomes a berry, so the inflorescences become bunches of grapes, which have evolved to be attractive to animals that eat the grapes and disperse the vine’s seeds.
When do shoots turn woody?
During the winter after they have grown
When do buds burst?
The spring after they have formed
Why is it important to manage one year old wood?
Because vines will normally only produce fruit on shoots that grow from buds that developed the year before
When is the vine usually pruned?
Every winter
What is a cane?
One-year-old wood which is left with 8-20 buds
What is a spur?
One-year-old wood which is left with 2-3 buds after pruning
What is permanent wood?
Wood that is more than one year old
Where is the permanent wood on the vine usually?
The trunk and the arms
What are the functions of the roots?
- To absorb water and nutrients from the soil
- To anchor the vine
- To store carbohydrates for the winter
Vitis vinefera is the main ________ species.
Eurasian
How many important species of vine native to North America?
Three
How many grape varieties belonging to the V. vinefera species?
Thousands
Why researchers constantly looking for new grape varieties?
- they want varieties that can thrive in certain climate and soil conditions
- improved disease resistance
- deliver a higher quality or quantity of grapes.
Example of an exception variety created by hybrid using American vine as a parent
Vidal in Canada
Buds can be described as….
embryonic shoots
functions of glucose to a vine
Glucose is a sugar that is used to support vine growth and make ripe grapes taste sweet.
Each flower that is successfully pollinated, becomes a….
berry
What is one-year-old wood?
Shoots turn woody during the winter after they’ve grown. The following spring, they become one-year-old wood.
