Flashcards in Unit 1 Viticulture- The Vine Deck (53):
What is the function of the roots?
Absorb water and nutrients, store carbohydrates to allow winter survival, anchor the vine
What part of the vine stores CHO?
Trunk and arms
What is the difference between prompt and dormant buds?
Prompt buds break in the same year they are formed, and dormant buds break the following spring
How can you determine the nutrient requirements of a vine?
Petiole (leaf stalk) analysis
What are tendrils?
Tendrils search out trellis wires and wind around them, enabling shoots to stay upright
What natural factor can result in low fruit set?
Too much rain or wind during flowering which can blow away the pollen
What is wood ripening?
When CHO are stored in canes to provide energy for the following year, after version and before ripening
What is the result of shoots being destroyed by spring frost at bud burst?
Secondary buds will grow but are much less fruitful
What is coulure ?
Failure of fruit set
How are vines treated in the first two to three years of growth?
The vine grows its trunk and permanent wood, the vine must focus on vegetative growth, so bunches are usually removed, the root system is established
Why can the first few crops from a vine be very high quality?
The trunk and arms are thin, the CHO reserves are low, which limits the vigour of shoot growth. This results in a very good fruit to leaf balance and well exposed fruit.
What happens to the vine between 7 and 20 years?
- Permanent wood thickens (but less and less)
-Canopy needs to be managed to avoid excessive shading
- Potential yields are the highest
-Quality drops after the first few years
What happens to the vine after 20 years?
- Declining vigor
-Fruit to leaf balance is restored to early year levels but yield declines
- The grower may replant, or may be used as old vines
What are the 4 main criteria to consider when selecting vines?
1. Adaptation to climate
2. Resistance to disease
3. Adaptation to soil conditions
4. Economic characteristics (High yield, mechanization high quality)
Where are interspecific hybrids forbidden?
What are interspecific hybrid varietals?
Crosses of one vinifera varietal with another
What are some examples of interspecific hybrid varietals?
Muller-Thurgau, Alicante Bouschet
What is mass selection and why is it no longer used?
Passing through vineyard before harvest and marking the best plants from which to take cuttings, not done due to necessity of grafting instead of taking cuttings and success of cloning
What is cloning?
Plants originating from a single parent propagated vegetatively by cuttings and therefore genetically identical
On what was clonal selection first carried out on?
Silvaner in Germany
What is the difference between clonal selection and mass selection?
With clonal selection only a handful (<10) of plants are selected and propagated extensively, whereas mass selection results in poly-clonal populations
What 7 factors are used to select clones?
1. Yield (fertility, berry size)
2. Sugar concentration
3. Phenolic constituents
4. Resistance to disease and draught
5. Freedom of viral infection
6. Ease of grafting
What are the 4 disadvantages of clonal selection?
1. Disease spreads easily
2. Clones are very specialized to certain regions/styles of wine
3. Leads to increase in yield/overproduction
4. Led to reduction in vine genetic resources
Are GM vines available for use in commercial vineyards?
What is layering?
When vine canes are buried in the ground then separated from the parent plant once they have established their own roots
What two species are difficult to root from cuttings and benefit from layering?
Why are vines not grown from seeds?
Propagation from cuttings is easier, allows for grafting on phylloxera resistant rootstock, it is difficult to predict characteristics of plants grown from seeds
What is the best time to take cuttings?
Autumn or early winter when CHO reserves are high
How are cuttings treated after taken from the parent vine?
30-45 cm long, bundled, labelled, stored at 5C prior to grafting, they can be heat treated by placing them at 50C for 30 min in order to rid them of pests and nematodes, if they are not grafted they can be planted right away
How do you grow cuttings successfully?
-Lots of water
-Keep them warm (15-25C)
-Use loose well drained soil that has good aeration and drainage
What is head grafting?
Changing varieties in an established vineyard (just the top and leaving rootstock)
What is done in bench grafting?
Bench grafting is indoors, scion is soaked then dipped in paraffin wax and grafted to the root, they are stored in high humidity crates and they join together with a callus of cells. `
What is top grafting good for?
Change cultivars in an established vineyard
Which type of v. vinifera is used today- silvestris or sativa?
Sativa- good fruit set, large fruit. Sativa eliminated by phylloxera
Can v. vinifera be planted ungrafted?
Only in phylloxera free areas, resistance to nematodes is also poor
What species is used mostly as a rootstock and have a good resistance to phylloxera but suffer from iron deficiency in chalky soils?
What species is used as a rootstock and susceptible to chlorosis?
What species is hybridized with riparian and rupestris in order to produce lime resistant rootstocks ?
What flavours to lees and age add to chardonnay?
Lees: Yogurt, creaminess, savouriness
Age: Hazelnut, honey, oatmeal, toast
What type of fungal disease is chardonnay prone to?
What aromas are typical of a cool climate pinot gris?
Honeyed, nutty, earthy, tropical fruit, spicy, medium acidity
What are the two ways "pink pinot grigio" is made?
By taking advantage of the variety's tinted skin or blending a small quantity of red wine
How is pinot blanc similar to chardonnay?
On the nose- pear, green apple, citrus, dry, high acid- but generally lighter in body and less complex
What does pinot blanc blend with in Alsace?
Why is gewürztraminer usually high alcohol?
It is difficult to achieve flavour ripeness at moderate alcohol levels
What muscat variety is usually dry or off dry?
What notes can you get from muscat blanc a petit grains?
Grape, peach, floral, orange blossom, rose, spice, medium acidity and usually sweet
- more complex than muscat ottonel or muscat of alexandria
Where is muscat ottonel grown?
Alsace and central europe
What are three negatives about the muscat grape?
1. Prone to mildew
2. Attracts insects
3. Unless oxidatively aged, wines fade quickly
What makes chenin blanc hard to harvest?
It ripens unevenly, resulting in the need to try and avoid unripe/leafy flavours at harvest
What does the label fume blanc usually indicate?
Oak aged sauvignon blanc from USA
Why is viognier never heavily oaked?
Its flavours are delicate, can easily be lost in oaking