Chapter 6: Vineyard Management

Question 1

Site Selection:

Answer 1

When a producer wants to establish a new vineyard, the potential site needs to be assessed for its environmental and practical suitability

Question 2

Environment Conditions:

Answer 2

• The grape grower can use data to work out the potential site’s average:
• Temperature
• Rainfall
• Sunlight Hours
• Fertility of the soil and how well drained it is
• These factors will influence the choice of grape variety as well as the ideal planting density and systems of training and trellising

Question 3

Business Considerations:

Answer 3

• The proximity of a vineyard to the utility infrastructure ( power, water, etc)
• The availability of a vineyard workforce
• The accessibility of a site for machinery, such as: tractors and harvesters
• The cost of the land are all important considerations, in the financial viability of a site

Question 4

Grape Variety:

Answer 4

• The grape variety must suit the climatic conditions of the preferred site
• There must also be a demand for the grapes
• In EU vineyard areas there may also be legal restrictions on the varieties that a producer can use

Question 5

Planting/ Replanting: ( Part 1)

Answer 5

• A new vineyard site must be cleared of any existing vegetation as necessary
• The fertility of the soil may be tested and fertilizers applied to correct any nutrient deficiencies
• Young vines usually bought pre- grafted from a nursery, are planted either by hand or machine
• The young vines are often protected against animals by individual plastic sleeves
• Irrigation is also sometimes allowed, even in regions where it is otherwise prohibited, for help young vines establish themselves
• The first yield, usually comes in the third year after planting
• Although, they can be very long lived, most vines are replaced between the ages of 30-50 years old

Question 6

Planting/ Replanting: (Part 2)

Answer 6

• Some wine estates, will use the term “ Old Vines” or its local equivalent, to denote a wine made from well - established plants
• These vines are thought to produce fruit of exceptional quality, often with a greater concentration of flavors
• The quantity or yield of grapes a vine produces, decreases with age, and it can be increasingly susceptible to disease
  -. A balance has to be struck between quality and profitability
• A vineyard land is left fallow ( unplanted) for three (3) years or more, after the vines are dug up so that it can recover
• A grape grower will have a replanting cycle, that ensures that as little of their vineyard as possible is out of production at any one time

Question 7

Managing The Vine:

Answer 7

• Training, Pruning, Trellising and the Density of the Planting are the main techniques used to manage the vine
• The grape grower will adapt these practices to suit the vineyard’s resources:
• Temperature
• Sunlight
• Water
• Soil Nutrients
• He/She will also take into account practical considerations, such as: the use of machinery in the vineyard
• In all cases the grape grower’s goal is to maximise the production of fruit at the desired quality level as economically as possible
• The interrelationship between all of these factors is extremely complex

Question 8

Vine Training:

Answer 8

• Vine Training typically refers to the shape of permanent wood of the vine and can be split broadly into two categories
  1. Head Training
  2. Cordon Training
• Either system can be:
• Low- trained to benefit from heat retained by the soil
• High trained to avoid frosts

Question 9

Head Training:

Answer 9

• These vines have relatively little permanent wood
• Some only have a trunk
• Some others have a few short arms of permanent wood growing from the top of the trunk
• They can either be “ Spur- Pruned or “ Replacement Cane Pruned”

Question 10

Cordon Training:

Answer 10

• These vines typically have a trunk with one or more permanent horizontal arms or “ Cordons”
• The vines are usually Spur- Pruned
• Cordon Training takes longer to establish because of the greater amount of permanent wood
• The sturdy permanent Cordon with shoots positioned along its length makes mechanization in the vineyard, such as: machine harvesting, easier to achieve
• Vines normally have one or two Condoms, but Cordon Training, can also be used to create big vine structures, where shoots may grow from four or more Cordons

Question 11

Vine Pruning:

Answer 11

• Pruning is the removal of unwanted leaves, canes and permanent wood
• It shapes the vine and limits its size
• Pruning will take place every winter and summer
• Winter Pruning is an important part of the vineyard calendar and its main purpose is to determine the number and location of the buds that will form shoots in the coming growing season
• It is important to make sure that the buds are not close together
• This helps with Canopy management
• There are two styles of Winter Pruning:
• Spur- Pruning
• Replacement Cane Pruning

Question 12

Spur- Pruning:

Answer 12

• “ Spurs” are short sections of one year old wood, that have been cut down to only two to three buds
• The Spurs are either distributed along a cordon of permanent wood ( Cordon Training)
• Or around the top of the trunk ( Head Training)

Question 13

Replacement Cane Pruning:

Answer 13

• Canes are longer sections of one year old wood
• Can have anything between 8 and 20 buds
• Typically only one or two canes are retained and each cane is tied horizontally to the trellis for support
• This type of pruning is most often seen on head- trained vines
• Replacement Cane Pruning is more complex than Spur- Pruning
• Requires a large skilled labour force to choose suitable canes and training them
• It is sometimes referred to as “ Guyot Training”
• One Cane is retained in Single Guyot
• Two Canes in Double Guyot

Question 14

Summer Pruning:

Answer 14

• Involves trimming the canopy to restrict vegetative growth and direct sugar production to the grape
• Rather than to the growth of shoots and leaves
• It can also involve leaf stripping so that bunches of grapes have optimum exposure to sunshine

Question 15

Trellising and Canopy Management:

Answer 15

• The vine’s canopy is made up of all of the green parts of the vine
• Managing this annual growth is a very important part of grape growing and grape growers must choose between a number of techniques
• The most important choice concerns whether or not to use a trellis
• Trellises are permanent structures of stakes and wires that are used to support any replacement canes and the vine’s annual growth

Question 16

Untrellised Vineyards: ( Bush vines or Gobelet)

Answer 16

• In, some regions the vines may not have a trellis system and the shoots will hang down often as far as the ground
• These are called “ Bush Vines” and they are typically head- trained and spur- pruned
• This system is best suited to warm and/ or hot dry sunny regions, such as the Southern Rhône in France and the Barossa Valley in Australia where the extra shade helps to protect the grapes
• In cool or wet regions the shade can impede grape ripening and the lack of airflow can promote disease
• This is avoided in Beaujolais France where the shoots of head- trained, spur- pruned vines are tied together at the tips, which helps expose bunches to air and sunlight
• Untrellised vines are not suitable for mechanical harvesting

Question 17

Trellised Vineyards:

Answer 17

• Each row of vines requires a line of posts joined by horizontal wires
• The vine’s canes and shoots are then tied to the trellis
• Together, this is known as “ Canopy Management”
• There are three important reasons for doing this:
  1. - The arrangement of the young shoots can be used to control the amount of sunlight that gets into the canopy
  
  • In regions with limited sunlight, keeping the shoots apart to create an open canopy maximises the grapes exposure to sunlight helping the grapes to ripen successfully
  • In regions with intense sunlight keeping the grapes shaded by leaves may reduce grape sunburn, a problem that can lead to bitter flavours

2. • An open canopy can improve air circulation through the leaves and grapes
   • This is important in wet climates because damp stagnant air can promote fungal diseases
3. • Trellising can aid mechanisation in the vineyard
   • Positioning the grapes in one area of the vine and the leaves in another means that mechanical harvesting is simplified and the spraying of insecticides or fungicides is more effective

Question 18

VSP ( Vertical Shoot Positioning): ( Trellised Vineyards)

Answer 18

• The most widely used system is Vertical Shoot Positioning ( VSP)
• It can be used with replacement cane or spur- pruned vines
• The vine’s shoots are trained vertically and are tied in place onto the trellis forming a single narrow canopy
• By keeping the shoots apart this system keeps the canopy as open, well aerated and shade free as possible
• In hot sunny regions, VSP can be adapted so that the tops of the shoots are not tied in, but flop over creating some shade in the canopy to protect the fruit
• A producer would choose to use this system rather than an Untrellised Bush Vine because mechanical harvesting can be used

Question 19

Density:

Answer 19

• Planting density is the number of vines that are planted in a given area
• This is typically expressed as the number of vines planted per hectare
• A hectare is an area enclosed by a square with 100 meter sides
• Planting densities can vary from as low as 1000 vines per hectare to as high as 10 000 vines per hectare
• ( Some countries use acres. One acre is approximately 0,4 hectares)
• There are many factors that influence a grape grower’ s decision regarding planting density
• One very important set of criteria that can, is the availability of nutrients and water

Question 20

Very Limited Water Availability:

Answer 20

• Some regions have very low levels of rainfall or very limited access to irrigation
• In these circumstances, low planting density can be beneficial, as it allows each vine’s roots to take up water from a large volume of soil without having to compete against the roots of neighbouring vines

Question 21

Low Levels of Nutrients and Sufficient Rainfall:

Answer 21

• Provided it can access enough water, a vine will thrive in barely fertile soil
• Left unchecked it will grow vigorously and produce a lot of green vegetative growth in preference to fruit
• In order to counteract this, vines may be planted at a high density
• This provides enough competition for resources among the roots to restrict the vine’s vegetative growth
• Ensuring that the vine has the correct number of buds after winter pruning is also important
• The vine stores energy in the form of carbohydrates over winter
• If there are too few buds then each bud will have access to too much energy and will grow vigorously
• If there are too many buds, each one will not have access to enough energy and the vine will struggle to ripen its crop load
• When managed correctly, this combination of density and pruning makes it easier to maintain an open canopy, with all the advantages this confers on fruit quality and disease control
• High planting density with strict control of the number of buds on each vine is common in many European vineyards

Question 22

High Levels of Nutrients and Sufficient Rainfall:

Answer 22

• While very fertile soils are not suitable for viticulture
• There are some vineyard areas, where plentiful nutrients, together with sufficient rainfall, promote vigorous vine growth
• Here high- density planting is often not enough to limit the growth of the vines
• Solution has been developed that involves low- density planting using vines with multiple cordons or canes
• This system is often able to produce good quality grapes at high yields

Question 23

Yields:

Answer 23

• Yield is a measure of the amount of grapes produced
• It may be measured in terms of weight, such as: tonnes of grapes per hectare or volume such as: hectolitres of wine per hectare
• It is important for a producer to be able to manage and predict yields
• Producer may need to observe legal requirements, such as those that exist in the EU
• They may have to meet contractual obligations or the winemaker may simply need to know how much tank space they need to make their wine
• Predicting yields is not straightforward
• An estimate can be made from the number of buds left on the vine after winter pruning
• Frost damage, poor fruit set and pests and diseases can all dramatically reduce the final figure
• If yields are going to be too high then they can be reduced by removing immature grapes shortly after Veraison
• This practise, known as “ Green Harvesting” is risky because, if it is done at the wrong time the vine will compensate for the loss by increasing the size of the grapes that have been retained
• This can not only return the yield to the original size but will also dilute the flavours in the remaining grapes

Question 24

Yields and Quality:

Answer 24

• Traditionally there was a view that high fruit quality could be only achieved by low yields of grapes, it is in fact very hard to make any solid link between quality and yield
• There are number of factors that can affect the relationship between yields and fruit quality, many of which will depend on the individual vineyard site

Question 25

Managing Vineyard Pests and Diseases:

Answer 25

- Vines are susceptible to many pests and diseases - The presence of which may result in a drop in yield and/or reduce the quality of the fruit - Grapes may be lost or damaged by disease or hungry animals - Damage to leaves reduces photosynthesis and limits the vine's ability to ripen its grapes - Some pests and diseases can be controlled , others may kill the vine

Question 26

Pests: - Phylloxera:

Answer 26

- Is an insect native to North America - Has a very complex life cycle taking different forms throughout the year - During one phase it lives underground and feeds on the roots of the vine - Infections enter through the feeding wounds and over of a few years the vine is weakened and dies - Cannot be controlled with chemicals

Question 27

Pests: - Nematodes:

Answer 27

-These are microscopic worms that attack the roots of vines interfering with water nutrient uptake - In certain instances they transmit vine viruses - In terms of treatment , prevention is better than cure - Sanitising the soil, before replanting and using resistant rootstocks have been found to be successful

Question 28

Pests: - Birds and Mammals:

Answer 28

-They can both consume large volumes of grapes - Half- eaten or crushed grapes can lead to an increased risk of fungal diseases - “ Netting” is often the best option against birds - “ Protective Fencing” may be needed to deter mammals, such as: rabbits, deer or wild boar

Question 29

Pests: - Insects:

Answer 29

- They feed on both grapes and leaves - The grape grower may choose to treat the problem with regular spraying of insecticides or a more environmentally friendly technique, such as: integrated pest management

Question 30

Fungal Diseases: - Downy Mildew:

Answer 30

- This fungus thrives in warm, wet and humid conditions - Can affect all of the green parts of the vine - It appears as yellow spots on the upper side of leaves or furry grey patches on the underside - In severe cases the leaves, it causes the leaves to drop prematurely - Inflorescences and very young grapes can also be affected, causing reductions in yield

Question 31

Fungal diseases: - Powdery Mildew:

Answer 31

- This fungus thrives in warm, shady conditions with some humidity - It can affect all of the green parts of the vine including the leaves and grapes - Appears as a grey-white powdery coating - With severe infections, leaves can dry up and drop off the vine prematurely -Infected grapes may shrivel and split or fail to ripen properly

Question 32

Fungal diseases: - Grey Rot:

Answer 32

- This is caused by the fungus Botrytis Cinerea - It thrives in damp conditions and typically attacks grapes - It can taint grape flavours and lead to colour loss in black grapes -In certain conditions and for certain white grape varieties a Botrytis Cinerea infection can be beneficial as it helps, to produce some of the finest sweet wines in the world -In this case the infection is called “ Noble Rot”

Question 33

Fungal diseases:

Answer 33

- Fungal diseases can be controlled using chemical sprays ( fungicides) -Traditionally Powdery Mildew was treated with a sulfur-based spray - Downy Mildew with Bordeaux mixture, a copper-based spray -These treatments are still used but many new chemical treatments now exist -Spraying is usually done by tractor -More sprayings are required in maritime climates, where there is high rainfall during the growing season - All spraying must stop close to harvest time, so, that there are no harmful chemical residues in the wine - The risk of fungal disease developing can also be reduced using appropriate canopy management - A dense vine canopy, restricts airflow and prevents water from evaporating, creating a humid environment - An open vine canopy, allows a greater flow of air which promotes evaporation and keeps it as dry as possible - This has the added financial and environmental advantages of reducing the usage of chemical sprays, which when used,can reach into all parts of the canopy more easily

Question 34

Other diseases: - Viruses:

Answer 34

- Numerous viruses can infect vines - Most do not kill the vine, but by limiting the vine’s ability to function they can reduce yield and quantity - Viruses are highly contagious and persistent and are usually spread via cuttings or Nematodes - There are no treatments or cures - Viruses can only be eradicated by digging up the vines and sanitising the land

Question 35

Others diseases: - Bacterial Diseases:

Answer 35

- A large number of bacteria can also infect a vine - Many just reduce grape quality and quantity but some can kill the vines - Typically these diseases are spread by small insects called “ Sharpshooters” - There are no treatments or cures - Strict quarantine procedures and interrupting the lifecycle of the Sharpshooters are the only ways of preventing the spread of these diseases - As with viruses once a vine is infected, the disease can only be eradicated by digging up the vines and sanitising the land

Question 36

The Vineyard Cycle: 1. Budburst:

Answer 36

* March - April in the Northern Hemisphere * September - October in the Southern Hemisphere - Budburst occurs in the spring. Buds swell and burst, growing into new shoots - Budburst is the start of the growing season - Generally begins when the mean temperature exceeds 10°C (50°F) - The temperature at which budburst occurs depends on the grape variety - Chardonnay and Pinot Noir bud at relatively low temperatures and are called "early-budding varieties'' - Cabernet Sauvignon is a late-budding variety needing warmer conditions - New shoots can be killed by spring frosts, reducing yields, significantly, particularly in early-budding varieties - Spraying against fungal diseases and pests, it practised begins at this time

Question 37

The Vineyard Cycle: 2. Early Shoots and Leaf Growth:

Answer 37

* March- May in the Northern Hemisphere * September- November in the Southern Hemisphere - Shoots grow rapidly until the vine flowers - Initially this is fueled by the vine’s carbohydrates, reserves stored over winter, but as the leaves mature they support the growth via photosynthesis - The vine needs a good supply of water and sufficient nutrients early in the season - If practised shoots are tied to the trellis to ensure the canopy remains open - Spraying continues as necessary

Question 38

The Vineyard Cycle: 3. Flowering and Fruit Set:

Answer 38

* May- June in the Northern Hemisphere * November- December in the Southern Hemisphere - When the inflorescences start flowering the vines needs: warm temperatures, plenty of sunshine and little or no rain, otherwise pollination can be disrupted, reducing fruit set - Fruit Set occurs when a flower starts to develop into a grape - Not every flower becomes a grape and after fruit set unpollinated flowers drop off - If more flowers than normal fail to fertilise this condition is called "Coulure” - Grapes can also sometimes form without seeds and remain small, this is known as " Millerandage” - Both of these conditions reduce yields and usually stem from cold, cloudy or rainy weather during the pollination period - Spraying continues as necessary

Question 39

The Vineyard Cycle: 4. Veraison and Berry Ripening:

Answer 39

* July- September in the Northern Hemisphere * January- March in the Southern Hemisphere - After Fruit Set there is a period of six to eight weeks during which time the grapes start to grow - Both black and white grapes are green at this stage and the grapes feel hard - Veraison signals the point at which the grapes begin to ripen - The grapes skins change colour: 1. Black varieties turn red then purple 2. White varieties become translucent and golden - Between Veraison and harvest, grapes swell and fill with water - During ripening, grape sugar levels rise and the acid levels drop - Colour pigments and flavour compounds also accumulate at this time and tannins develop - Warm and sunny conditions are ideal - Mild water stress inhibits shoot growth encour ages grape ripening - If required, summer pruning takes place to remove excess foliage ensuring the canopy remains open - “ Green Harvesting” (the removal of a proportion of a grape bunches) may take place shortly after Veraison to control yield and improve fruit quality - Not all grape growers use this technique - Spraying continues as necessary

Question 40

The Vineyard Cycle: 5. Harvest:

Answer 40

* September- October in the Northern Hemisphere * March- April in the Southern Hemisphere - Ideally the harvest period, should be dry - Excess rainfall before harvest can cause grapes to swell,diluting the juice and due to damp conditions it can increase the risk of rot - Where practised, spraying must have finished early enough to ensure that there are no harmful chemical residues in the wine

Question 41

The Vineyard Cycle: 6. Winter Dormancy:

Answer 41

* December- March in the Northern Hemisphere * June- September in the Southern Hemisphere - As the weather becomes colder, the growing season ends and a period of winter dormancy begins - The shoots become woody and from this point are known as “ Canes” - The leaves fall and the vine stores its reserves of carbohydrates in its roots - In Continental climates, winter breeze can kill buds and in extreme cases the vine itself - Earth may be piled up around the vine to provide some protection - Winter pruning takes place

Question 42

Viticultural Practises:

Answer 42

- In the second half of the twentieth century the use of man-made chemicals in the vineyard to control pests and diseases significantly increased - There was also a increased use of chemical fertilisers - A number of grape growers still rely on regular and systematic applications of man-made chemicals to protect their vines and fertilise their land - The extent of environmental damage that this amount of chemical spraying has caused both in vineyards and the surrounding areas has become an increasing worry to many grape growers, consumers and legislators - In many major vineyard regions, there are increasing efforts to reduce the quantity of chemicals used - Three main options available grape growers wishing to do this:

Question 43

1. Sustainable Agriculture:

Answer 43

- Man-made chemicals are not prohibited in sustainable agriculture but their use is restricted - Grape growers are encouraged to develop an in-depth understanding of the life cycles of vineyard pests and monitor weather forecasts, so that they can predict and prevent a pest or disease outbreak before it occurs - Rather than, simply following a regimented calendar of spraying, this enables them to time the applications, so they have the greatest impact. As a result, fewer applications are needed - Integrated pest management is a key part of sustainable agriculture - The predators of certain pests may be encouraged to live in the vineyard to control pest populations naturally - This makes vineyard biodiversity essential - Supporting a range of plants in the vineyard rather than a monoculture of vines can provide habitats for predators of pests, help to capture carbon dioxide and provide nutrients for vines when they are mowed and ploughed into the soil

Question 44

2. Organic Agriculture:

Answer 44

- Organic agriculture encompasses many of the same concepts as sustainable agriculture - Only a very limited number of the more traditional treatments against pests and diseases is allowed and only in very small quantities - Accreditation is required from an organic certification body, it the producer wishes to display the organic credentials of their grapes on the label - There are many certification bodies throughout the world - Many of these organisations operate on similar principles,the exact standards each one sets may be slightly different - Therefore, perhaps confusingly some wines made from organically formed grapes may have been subject to stricter rules than others - A universal requirement is that the vineyard must undergo a period of conversion working to organic standards before it can be certified

Question 45

3. Biodynamic Agriculture:

Answer 45

- Biodynamic agriculture is based on the work of Rudolf Steiner and Maria Thun - It adopts organic practises but also incorporates philosophy and cosmology - The vineyard soils is seen as part of a connected system, with the planet Earth, the air and other planets - Practitioners adapt their grape growing practises to coincide with the cycles of the planets, moon and stars - Homeopathic remedies called" preparations" are used to fertilise the soil, treat diseases and ward off pests - There are also certification bodies for biodynamic agriculture

Question 46

Harvest:

Answer 46

- Veraison is the point at which the grapes begin to ripen. It is signalled by change in colour of the grape's skins: * Black varieties turn red then purple * White varieties become translucent and golden - As the grapes ripen, sugar levels rise and acid levels drop - Monitoring the rise in sugar levels is a common way of tracking the ripening process - At this time grapes, also develop their signature flavours and the tannins in the skins of the grapes become less bitter and astringent - There is no completely hard and fast rule that states when a grape is perfectly ripe - The ideal balance between sugar, acid, flavour and tannin will vary depending on the grape variety, the climate and importantly the style and quality of the wine being produced - Ideally the harvest begins, when the grape grower and/or the winemaker believes that the grapes have the exact qualitiesthey need to create the desired style of wine - Poor weather conditions may cause a grower to bring the harvest forward to save their crop - Hail can destroy grapes and rainfall can cause the grapes to swell excessively and dilute the juice - Winemaker also need to coordinate the arrival of the fruit at the winery to make sure it is not suddenly overwhelmed with fruit, it does not have the capacity to process - Harvesting can be done by hand or machine - The decision, to use either method will depend on a number of factors,including now the vineyard is planted, labour availability and cost, the topography of the vineyard, weather conditions and winemaking choices - Premium wine can be made from machine- harvested as well as hand- harvested grapes

Question 47

Machine Harvesting:

Answer 47

- Machine harvesters work by shaking the trunk of the vine and collecting the ripe berries as they fall off, leaving the stalks behind - They are not selective, often collecting some unhealthy unripe and damaged grapes, as well as shaking off bits of leaf, insects and other contaminants, referred to as MOG ( matter other than grapes) - These unwanted elements can be removed during sorting when the grapes arrive at the winery - The scale of some harvesting operations means that this is not always possible - An important advantage of the machine harvester is speed * This might be essential, it the vintage is threatened by bad weather, or with certain grape varieties, such as: Sauvignon Blanc, than can become over-ripe very quickly - Machines can also work through the night, which allows cool grapes to be brought to the winery * This saves money and energy that would be spent on lowering the temperature of the grapes before fermentation and it slows down the process of oxidation - which could lead to off flavours - Harvesting machines can only be used on flat or gently sloping land are best suited to varieties whose grapes are not easily damaged and come away easily from their stem - They cannot be used to pick grapes for wine styles that require whole bunches, such as: Beaujolais or Champagne

Question 48

Hand Harvesting:

Answer 48

- Hand harvesting (also referred to as hand picking) involves pickers cutting off individual bunches of grapes with secateurs - It is slower and more labour intensive and for this latter reason it can be more expensive it there is no large workforce to land - It does allow grape selection to take place in the vineyard, rotten or unripe grapes can be left on the vine - For grapes affected by noble rot, hand picking is essential because the onset and level of rot can vary between bunches and even within a bunch, meaning careful selection is needed - Less damage, tends to occur to the grapes when they are manually harvested and the grapes can be further protected from damage by being transported in shallow stackable trays - Unlike machine harvesting, the grape stems are retained * This gives, whole intact grape bunches that can produce a very clean cure juice, when pressed in white wine making and that are essential for whole bunch fermentations in red winemaking - Hand harvesting may also be the only option steep vineyard slopes, such as many of those found in the: * Douro in Portugal * Mosel in Germany * Northern Rhône in France