The vine, growing environment and vineyard management (ch4-7) Flashcards
Name the two vine species that we can identify, and describe what they are used for.
- Vitis vinifera; the main Eurasian species producing nearly all grapes for wine production
- American vines. Rarely used for wine production because of unattractive flavours, but produce rootstocks to which Vitis vinifera can be grafted. American vines are resistant to Phylloxera.
Describe the two techniques the vinegrower can use to grow or propagate a grape variety.
- Cutting. Take a section of a vine shoot and grow it as a new plant
- Layering. Bend down a cane and lead it under the ground, make it come up somewhere else. The part underground starts growing roots, and then is cut from the original plant.
So all grapes of one variety are identical, and the group of individual plants can be traced back to the original plant through a series of cuttings and/or layerings.
What is a ‘cultivar’?
A cultivar is the same as a variety (vine variety or grape variety)
What is a ‘clone’, and describe ‘clonal selection’.
A clone is an individual vine or group of vines that shows a particular set of unique characteristics (for example high drought resistance, disease resistance or certain flavour characteristics).
Clonal selection is propagation by cutting or layering of vines with positive mutations from an original variety, so the positive characteristics of this mutation can be carried forward in new plantings.
Describe how a new grape variety is created by fertilization, and why only occasionally this yields positive results.
A new grape variety is formed by cross-fertilization, bringing pollen from the male part of the flower of a vine to the female part of the flower of another vine. The pollinated flower develops into a grape with seeds that can start to grow the new variety.
Many seeds are needed for cross-fertilization, and many seedlings fail in the first two years. On top, it takes many years before you have production of a new variety and the quality and characteristics can be judged. So this process is costly and time-consuming.
What is a crossing? Give two examples of well-known crossings in the wine world.
A crossing is the production of a new grape variety from two parents of the same species (so two parents of Vitis vinifera!).
Examples are:
Cabernet Sauvignon = Cabernet Franc x Sauvignon Blanc
Merlot = Cabernet Franc x Magdeleine Noire des Charentes
Müller Thurgau = Riesling x Madeleine Royal
Pinotage = Pinot Noir x Cinsault
What is a hybrid? Give one example of a well-known hybrid.
A hybrid is a vine whose parents are from two different species (Note: a clone comes from two parents of identical species!).
An example is Vidal (Canada), Baco Noir (Canada), Rondo (Europe) and Regent (Europe)
Describe what Phylloxera does to the vine.
Phylloxera is an insect that feeds on the roots of the vine. Infections can enter through the feeding wounds and infect the vine roots, weakening the roots and ultimately make the vine die.
American vines have a sap that clogs the mouth of the insects and form protective layers that close the feeding wounds so no infections can occur.
Describe the two forms of grafting.
Grafting is to join a rootstock to a Vitis vinifera variety (providing the protection to Phylloxera of the rootstock and the flavor of the European vine.
- Bench grafting joins two sections of cane of both the Vitis vinifera and the rootstock variety by machine, stored in a warm environment to make the two parts fuse.
- Head grafting happens in the vineyard, cutting an existing vine back to its trunk or a cutting of the new variety is grafted onto the trunk.
Describe the four ‘green parts of the vine’.
The green parts grow each new year on the shoots (one-year-old wood):
- Buds: forming in the joint between the leaf and the shoot; they develop all structures that form shoot, leaves, tendrils and flowers the next year).
- Tendrils: these tendrils grip a supporting structure such as a trellis wire and wind itself around it to keep the shoots upright and support the shoots
- Leaves: Responsible for photosynthesis (sunlight is used to convert water and carbon dioxide into glucose and oxygen)
- Flowers and berries: flowers are the reproductive organs with male and female parts. Successful pollination makes a berry grow.
Describe the transformation over winter of the shoots and one-year-old wood.
Over winter, the shoots of the previous year become woody and are the one-year wood of next year. In spring of the next year, the buds burst and grow into the new shoots.
What are the two names for the one-year-old wood after winter pruning?
- A cane: long one-year-old wood with 8-20 buds
- A spur: short one-year-old wood with only 2-3 buds
What are the three functions of the roots of a vine?
- Absorb water and nutrients from the soil
- Anchor the vine
- Store carbohydrates to survive the winter
Explain the difference between budburst and fruit set.
Budburst happens early spring, and marks the start of the growth of new shoots.
Fruit set happens late spring, when the vine starts to flower and grapes start growing.
What is the defining factor determining whether a particular grape can grow somewhere?
Heat. The vine needs heat for flowering, fruit set, and ripening.
Name one soil factor that can make a vine-growing area warmer, and one soil factor that can make a vine-growing area cooler.
Warmer: dark soils, soils with high stone and rock content ensure that warmth is reradiated onto the vines.
Cooler: soils with high water content are cooler as they transport heat away from the vine.
Which factors in the vineyard contribute to the amount of heat the vine receives?
Except for sunlight, there is:
- latitude (30-50 deg regions)
- altitude
- ocean currents (Humboldt cools, Gulf Stream warms)
- fog
- soil
- aspect (the direction the vineyard faces, and the steepness)
Explain the difference between continentality and diurnal range.
Continentality is the difference in temperature between the coolest and warmest month (areas close to water masses generally have lower continentality, further inland higher continentality: continentality determines the length of the growing season)
Diurnal range is the difference in temperature between day and night (warm nights accelerate ripening, cool nights help to slow the loss of aromas and acidity: cloud cover reduces diurnal range (warmer nights, cooler days))
What is the risk of spring frost in the vineyard?
What 4 things can vinegrowers do to protect against spring frost?
Spring frost is a result of cold air collecting, freezing water vapor on the ground or the vine. At bud burst, this can kill the burst buds and the young shoots.
Vinegrowers use:
- Heaters
- Wind machines
- Sprinklers (spray water on the vines, water freezes and delivers heat to the vine protecting it)
- Thoughtful vineyard design (train vines high, avoid cold air to settle, put a vineyard on slopes)
How does latitude affect the amount of sunlight a vine has available to it?
The further away from the Equator, the longer the days are in summer, which provides extra sunlight (Riesling can ripen in Germany, which would not happen at lower latitude).
Explain why a vinegrower needs to regulate the amount of water available to a vine.
In spring, the canopy will need to grow, and water from the ground is needed to assist in the growth and supply of nutrients. Once the canopy has grown, it is good to limit the amount of water, such that the plant focuses on grape ripening rather than leaf growth.
Describe the three main irrigation techniques.
- Drip irrigation: every vine has its own dripper, causing an optimum amount of water but expensive
- Sprinklers: cheap but waste a lot of water and create damp conditions in the vineyard
- Flood irrigation: cheapest but only in flat vineyards
What are the four temperature categories for climatic indication?
- Cool climate (average growing season temperature below 16.5 deg)
- Moderate climate (average growing season temperature 16.5 - 18.5 deg)
- Warm climate (average growing season temperature 18.5 - 21 deg)
- Hot climate (average growing season temperature above 21 deg)
Describe the three climate categories.
1. Continental climate: high continentality, short summers with rapid temperature drop in autumn. Cool continental is at risk of spring frost, and low temperatures in growing season can affect flowering, fruit set, and ripening)
2. Maritime climate: cool to moderate temperatures, low continentality. Rainfall evenly spread. Grapes ripen far into the autumn (still rainfall in spring and summer can be negative)
3. Mediterranean climate: low continentality with warm and dry summers. Lower rainfall so less effect on the health of grapes, but also a risk of drought.
Describe the water-holding capacity of soils of clay, humus, sand, and stones.
Water is stored in the soil by binding to clay particles and humus (risk of becoming waterlogged)
Sand and stones do not hold water well and facilitate water drainage (risk of drought, even when there is high rainfall)
What are the main nutrients for a vine coming from the soil?
Nitrogen
Phosphorus
Potassium
What is chlorosis?
A lack of nutrients: the leaves turn yellow, less photosynthesis, fewer grapes, and lower quality grapes struggle to ripen. So vinegrowers need to use fertilizers to avoid this.
What are the two training systems the vinegrower can use in the vineyard?
Head training: Little permanent wood. Only a trunk, or just a few short arms of permanent wood. Can be spur-pruned or replacement cane-pruned.
Cordon training: One or more permanent wood arms (cordons), usually spur-pruned and suitable for machine harvesting.
What is the purpose of summer pruning and of winter pruning?
Summer pruning; the purpose is to restrict vegetative growth and direct sugar production to the grape, rather than to growth of shoots and leaves. Can also involve leave stripping to protect against excessive sunshine.
Winter pruning: determine the location and number of buds that will form from shoots in the coming year.
Name the two styles of winter pruning and explain what is done.
Spur pruning: cut short sections of one-year-old wood such that a few buds only remain. Spurs are around a cordon of permanent wood (cordon training) or at the top of a trunk (head training)
Replacement cane pruning: sections of one-year wood with 8-20 buds remain. Tie the remaining canes horizontally to the trellis. This is also called Guyot training.
What can be reasons to keep a vineyard untrellised?
In warm, hot or dry sunny regions you need extra shade to protect the grapes. This can be achieved by leaving the shoots to hang down.
In cool or wet regions you want to expose bunches to sunlight, so you can tie-up the shoots from head-trained spur-pruned vines so that more sunlight reaches the grapes. This system is called ‘gobelet’.
What are the 3 reasons for trellising the vineyards?
- Contol the sunlight into the canopy. An open canopy can help sunlight enter and reach all grapes, while a closed canopy provides shade and can prevent against sunburn.
- An open canopy can improve air circulation (wet climates: avoid fungal diseases)
- Aid mechanization in the vineyard.
How would wines be planted in a vineyard with limited water availability?
Low density so that each vine’s roots take water from a large volume of soil (no competition)
How would vines be planted in a vineyard with low levels of nutrients and sufficient rainfall?
There’s enough water, so avoid excessive vegetative growth by high planting density introducing competition between the vine roots. The number of buds after winter pruning is essential: divide the available energy stored in the vine in winter (the carbohydrates) over the right number of buds.
How would vines be planted in an area with high levels of nutrients and rainfall?
High-density planting is often not enough in these conditions and then low-density planting is used with multiple cordons or canes.
What are the most common pests in vineyards?
Phylloxera
Nematodes (microscopic worms: replant or use resistant rootstocks)
Birds and mammals (rabbits, wild boar): use fences or nets
Insects (use spraying with insecticides, or integrated pest management)
What are the most common fungal diseases in a vineyard?
Downy mildew: affects the green parts, off-flavors
Powdery mildew: affects the green parts, off-flavors
Grey rot: Botrytis cinerea, flavors and colors are lost. Use chemical sprays: fungicides, like Bordeaux mixture with sulfur or copper, and reduce the risk by canopy management)
How are bacteria commonly spread in the vineyard?
By sharpshooters. Can’t be treated. Only prevent by quarantine or interrupting lifecycle of sharpshooters.
Name the three methods of environmental-friendly vineyard control.
Sustainable agriculture
Organic agriculture
Biodynamic agriculture
What is characteristic for sustainable agriculture?
- Man-made chemicals are not forbidden but restricted
- Predators of pests can live in the vineyard to control pest populations
What is characteristic for organic agriculture?
- Only very limited number of treatments against pests and diseases allowed
- Accreditation is required
- Vineyard undergoes a period of conversion before it can be certified
What is characteristic for biodynamic agriculture?
- Organic practices combined with philosophy and cosmology
- Soil forms a system with the planet, the air, and other planets
- Preparations (homeopathic) used to fertilise the soil
What can be a reason to consciously choose for machine harvesting in the vineyard?
What are the disadvantages of machine harvesting?
It is quicker: you can harvest larger quantities in less time
Night harvesting is possible (cooler, slows down oxidation)
Disadvantage: berries can be damaged, lots of other materials (MOG = Matter Other than Grapes) comes off, only flat or gently sloping land, strong grapes required, not for whole-bunch fermentation
What can be a reason to consciously go for hand harvesting in the vineyard?
- Grape selection can take place in the vineyard
- Careful selection of noble rot affected grapes
- Less damage to the grapes
- Stems are retained
- Possible on steep slopes
- Disadvantage: slower, labor-intensive so costly
What is coulure?
Not all flowers become grapes: unpollinated flowers drop off after fruit set. If more grapes than normal fail to fertilize this is called coulure
What is millerendage?
Grapes form without seeds and remain small.
