Natural factors in the vineyards Flashcards
Cabernet Sauvignon crossing
Cabernet Franc x Sauvignon Blanc
Examples of hybrids
Vidal (Canada)
Muller Thurgau crossing
Riesling x Madleine Royale
Pinotage crossing
Pinot Noir x Cinsault
Most important vine species
Vitis vinifera - main Eurasian specie. Used to make wines for thousands years
American vines - unattractive flavour but resistant to Phylloxera so widely used to produce root-stock for vitis vinifera grafting
How many buds are retained with spur pruning?
a) 2 – 3
b) 4 – 7
c) 8 - 20
a)
What is a clone?
a) Cross of 2 Vitis vinifera grapes
b) Genetic mutation of a parent grape
c) Cross of a Vitis vinifera grape and another Vitis species of grape
b)
Which part of the vine is a cordon?
a) New shoots
b) Arm of permanent wood
c) The buds
?
Water hazards in a vineyard do not include:
a) Drought
b) Excessive water
c) Cloud cover
c)
What is the Phylloxera?
Insect from North America that attacks vitis vinifera. It was accidentally introduced in Europe in the XIX century and destroyed all the vineyards
Where the is not Phylloxera?
Chile, some parts of Argentina and South Australia
Solutions to Phylloxera?
(i) In the IX century the only certain way to deal with it, it was to plant American species or hybrids
(ii) After the IX century the vitis vinifera is crafted onto the root stock of an American vine or hybrid
What is grafting?
Grafting is the technique used to join a root-stock to a vitis vinifera variety
Describe bench grafting
The v. vinifera and the root-stock variety are joined together by machine and stored in a warm environment to encourage the parts to fuse together
Describe head grafting
The existing vine is cut back to its trunk and a bud or a cutting of the new variety is grafted onto the trunk.
Used to switch to a different grape variety between seasons (3 years). It can allow the grower to quickly adjust to market demand
Describe crossing
Crossing is when a new variety is produced from two parents of the same species
Example: Muller Thurgau = Riesling x Madleine Royal
Describe hybrids
Hybrid is a vine whose parents come from two different wine species (e.g. Vidal, Canada). Hybrids are often used as rootstocks
What is a one-year-old wood?
Shoots turning into woody after the winter, in springs become one-year-old wood. It will only produce fruits on shoots that grow from buds that developed the previous year.
Every winter the vine is pruned and the one-year wood will be called (i) spur (ii) cane depending on the number of buds it is left with
Definition of permanent wood
Wood that is more than one-year-old. It is made up of the trunk and arms of the vine (where presents)
Define spur
A cane is a one-year-old wood short with 2-3 buds
Define cane
A cane is a one-year-old wood long with 8-20 buds
What a vine needs?
(i) Heat [sun reflected from soil]
(ii) Sunlight [sun, reflected from water
(iii) Water [rainfall, irrigation, water stored in soil]
(iv) CO2 [atmosphere]
(v) Nutrients [soil, humus, fertiliser]
What is photosynthesis?
A combination of sunlight with CO2 and water, to produce glucose and oxygen. Then the glucose is combined with the nutrients to enable grapes’ ripening and the oxygen is lost through the leaves.
Which factors affect heat?
Latitude Altitude Ocean currents Fog Soil Aspect Continentality Diurnal range
How latitude is affecting heat?
Most vineyards lie between the latitude of 30° and 50° north and south of the Equator
How altitude is affecting heat?
As altitude increases, temperatures drop. This means that regions at high altitude grow vines even though they are close to the Equator (i.e. Cafayate, in northern Argentina)
Why Ocean currents is affecting heat?
Currents transport large volumes of warm and cold water across the surface of the ocean leading to warming and cooling in some regions (i.e. for hot regions cooling: Humboldt Current off Chile, Benguela Current off South Africa, for cold regions warming Gulf Stream off north-west Europe)
Why fog is affecting heat?
Fog can help cool and area that otherwise struggle to produce high quality grapes (i.e. California, Casablanca Valley in Chile)
Why aspect is affecting heat?
The aspect is the direction in which a slope faces. Aspects facing the Equator receive the most heat. This is very important for (i) cool climates where the extra warmth for ripening (ii) steeper slopes (i.e. Mosel, Germany for both)
Why continentality is affecting heat?
The temperature difference between the coldest and the hottest months. Lower in areas close to large bodies of water. The continentality determines the length of the growing season with an impact on the total amount of heat available for the vine
Why diurnal range is affecting heat?
Diurnal range is the difference between day-time and night-time temperatures. During ripening: (i) cool nights help slow the loss of aromas and acidity [for war climate with fresh and aromatic wine] (ii) warm nights accelerate it.
Diurnal range can be influenced by: (i) proximity to water that enables warm (ii) level of clouds as temperature drops more quickly during clear night (increasing diurnal range)
What is continentality?
The temperature difference between the coldest and the hottest months
Main temperature hazards
Winter for: (i) temperature -20° that can damage the vine (ii) mild winter for no dormant period so the vine can produce more than one crop and larger population of insects