Flashcards in C4 - The Vine Deck (61):
What are the most important species in modern viticulture?
Which vine species produces nearly all the grapes used in winemaking?
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?
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?
Where does layering take place?
In the vineyard
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?
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?
Which word can be used instead of variety?
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
What is clonal selection?
Choosing individual vines with beneficial mutations
Each individual vine or group of vines that shows a particular set of unique characteristics is known as a ...
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
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?
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
Give an example of a crossing
Cabernet Sauvignon (Cab Franc x Sauvignon Blanc)
What is a hybrid?
A vine whose parents come from two different vine species
What are hybrids and American vine crossings most commonly used for?
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
...has a very complex lifecycle
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 the aphid's 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 to some rootstocks other than resistance to Phylloxera
Protection against Nematodes
What is grafting?
It is the technique used to join a rootstock to a Vinifera variety
What is the most popular modern grafting technique?
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?
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 new variety will grow in the forthcoming season (much quicker)
It's much cheaper than replanting a whole vineyard
What can be used to protect a graft join?
What are leaves principally responsible for?
The process by which plants use sunlight to convert water and carbon dioxide into glucose and oxygen
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
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
Each flower that is successfully pollinated, becomes a berry, so the inflorescences become bunches of grapes, which have evolved to be attractive to animals (encouraging dispersion)
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?
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