C6 - Vineyard Management (reviewed) Flashcards
What are the three main considerations a producer may need to make when choosing a site?
Environmental conditions -
- Average temperature, Rainfall, Sunlight, Soil fertility, Drainage
Business considerations:
- Proximity to utility infrastructure (power, water etc.),
- Availability of a vineyard workforce,
- Accessibility for machinery Cost of land
Grape variety:
- It must suit climatic conditions,
- Demand,
- Legal restrictions
How is a new vineyard prepared?
- Existing vegetation is cleared
- Fertility tested (and corrected with fertiliser if necessary)
- Young vines are planted by hand or machine
- Vines protected from animals with plastic sleeves
- Irrigation allowed to help young vines establish themselves
- First yield usually comes 3 years after planting
Why is irrigation allowed in some places after new vines have been planted?
To allow the vines to establish themselves
Discuss vine age.
- First yield usually come in the third year after planting
- They are kept until they are 30-50 years old on average before being replaced
- Upside of old vines: greater concentration of flavours
- Downside: lower yield, more susceptible to disease
For how long is a vineyard typically left fallow after the vines are dug up?
- Three or more years
- A vineyard will have a replanting cycle that ensures as little of their vineyard is out of production at any point in time
What are the main techniques used to manage a vine? How will they adapt it?
Four main techniques:
- Training
- Pruning
- Trellising
- Planting density
These techniques are adapted based on
- Temperature
- Sunlight
- Water
- Soil nutrients
What is the ultimate goal of a grape-grower?
To maximise the production of fruit at the desired quality level as economically as possible
What is vine training?
The shape of the permanent wood of the vine. Two main training tpyes:
- Head training
- Cordon training
Both can be
- Low trained - to benefit from heat retained by the soil or
- High trained - to avoid frosts
Describe a head-trained vine
- They have very little permanent wood
- Some have only a trunk
- Some have a few arms growing from the trunk
- They can be spur-pruned or replacement cane pruned
Describe a vine which is cordon trained
- A trunk with one or two arms of permanent wood
- Usually spur pruned
- The sturdy permanent cordon with shoots positioned along its length, makes mechanisation easier
- It can take longer to establish because of the greater amount of permanent wood
- Can also be used to create big vine structures
What is vine pruning?
The removal of unwanted leaves, canes and permanent wood to shape the vine and limits its size. Happens every summar and winter
- Summer pruning: Trimming the canopy to restrict vegetative growth and direct sugar production to the grape It can involve leaf stripping so that bunches have optimal exposure to the sun
-
Winter pruning:
- Determines the number and location of buds that will form shoots in the coming season.
- Ensuring the buds are not too close to each other helps with canopy management (the green parts of the vine)
Why is it important to ensure that buds are not too close together?
To help with canopy management aka managing all green parts of the vine
What are the two styles of winter pruning? Describe.
Spur pruning -
- Spurs are short sections of one year old wood
- Spurs are either distributed along a cordon or around the top of the trunk
- 2 or 3 bud per spur
Replacement cane pruning (also called Guyot training)
- Typically one or two canes are retained
- Each cane is tied horizontally to the trellis for support
- Most common on head-trained vines
- It requires a large, skilled workforce to choose suitable canes and train them It is more complex than spur pruning
- 8-20 buds per cane
What is a grower’s most important concern when considering canopy management?
Whether to use Trellis or leverage Bush vine
Trellis:
- Permanent structure of stakes and wires, used to support any replacement canes and the vine’s annual growth
- Suitable for machine harvest as the trellis separates leaves from grapes
Bush vine (or Gobelet):
- The vines do not have a trellis system and the shoots can hang down as far as the ground,
- Extra shade helps to protect the grapes
- They are head-trained and spur pruned
- Ideal for Warm/hot, dry, sunny (e.g, Southern Rhône, Barossa)
- Not recommended for cool climate as the shade can impede grape ripening and lack of airflow can promote disease
- Not suitable for mechanical harvesting
Describe vines in Beaujolais
- They are head-trained and spur-pruned
- The buds are tied together at the tips, helping to expose bunches to air and sunlight
Describe the two main aspects of trellised vineyards. What is their collective term?
- Each row of vines requires a line of posts joined by horizontal wires
- Canes and shoots are tied to the trellis
- Canopy management
What are the main reasons for canopy management?
- To control the amount of sunlight that gets to the canopy
- To improve air circulation (important for wet climates)
- To aid mechanisation (havesting, spraying more effective)
What are the benefits of separating leaves and fruit via trellis system?
- Makes mechanical harvesting possible
- Spraying of insecticides and fungicides is more effective
What is the most widely used trellising system?
Vertical Shoot Positioning (VSP)
- Shoots are trained vertically and tied in place onto the trellis
- Both prunning methods are possible
In hot sunny regions
- VSP is adapted by allowing the shoot to flop over, providing some shade for the fruit rather than tying the top of the shoots
- A grape grower choose adapted VSP (over bush vine training) as it allows for mechanisation
Describe planting density.
- Measured by the number of vines planted in a given area (100m sides area)
- Rough range is 1,000 - 10,000 vines per hectare
- Density depends on availability of nutrients and water
- Low planting density allows each vine’s roots to take up water from a larger volume of soil without any competition
How does an acre relate to a hectare?
One acre is approximately 0.4 hectares
Explain the factors that can influence the grower’s decision regarding density
Availability of nutrients and water
Very limited water availability:
- Low planting density can be beneficial as it allows each vine’s roots to ake up water from a large voume of soil without having to compete
Low levels of nutrients but sufficient water:
- Plant at high density to provide competition for resources and production of a lot of green vegetative growth.
- Also ensuring the right number of buds after winter pruning is also important. If there are too few buds, each will have access to too much energy and grow vigorously. if too many buds, the vine will struggle to ripen the crop load.
High levels of nutrients and sufficient water:
- Not suitable for viticulture and high density planting may not be enough to limit the growth => use low density planting with vines with multiple cordons or canes. This can often produce good quality wines at high yields
How may pruning be used to affect vine vigour in a well watered area? Describe why accuracy is important.
Careful winter pruning can affect vine vigour
Too few buds left means the buds will have too much energy in the form of carbohydrates and will grow too vigorously and vice versa
What are the human-controlled factors in the vineyard which can affect vine vigour?
- Planting density
- Pruning
Discuss yield
- A measure of the amount of grapes produced - measured in Weight or Volume
- Approximated by observing the number of buds left on a vine after winter pruning but can be affected by Frost damage Poor fruit set and Pests and diseases
-
Can be reduced with removial of immature grapes shortly after véraison (green harvesting)
- If done at the wrong time, the vine will compensate for the loss by increasing the size of the grapes that have been retained, causing flavour dilution and a re-increase of yield
- Winemaker need to know yield in order
- Comply with Legal requirements
- Contractual obligations
- Predicting tank space
Why must green harvesting be carefully timed?
If done at the wrong time, the vine will compensate for the loss by increasing the size of the grapes that have been retained, causing flavour dilution and a re-increase of yield
What are the broad potential effects of pests and diseases?
- Reduced yield
- Reduced fruit quality
What effect does leaf-damage have on a vine?
It reduces photosynthesis and consequently limits the vine’s ripening ability
Discuss the different types of pests?
Phylloxera -
Nematodes:
- Microscopic worms that attack the roots of the vine, interfering with water and nutrient uptake and can transmit diseases.
- Best is prevention by sanitising the soil before replanting and using resistant rootstocks
Birds and mammals:
- They can eat large numbers of grapes and leave half eaten/crushed grapes are more susceptible to fungal disease.
- Nets and fences are best options against them.
Insects:
- Feed on grapes and leaves.
- Can be controlled with insecticide sprays or integrated pest management
Discuss fungal diseases
Downy and powdery mildew:
- Thrive in warm, humid environments
- Attack all the green parts
- Impact: grapes lose their fruity flavour and the wine develops a mouldy, bitter falvour
- Powdery mildew treated with sulphur-based spray
- Downy mildew treated with Bordeaux Mixture (copper based spray)
Grey rot:
- Caused by Botrytis Cinerea which can be beneficial for Noble rot
- Thrives in damp conditions
- Attacks the grapes, which can lose their colour
- Spraying is usually done by tractor and most stop close to harvest so that there are no harmful chemical residues in the wine
Mitigation
- Risk of fungal diseases can be reduced by using appropriate canopy management
- An open vine canopy allows greater flow of air, promoting evaporation and keeping it dry
- which is financially and environmentally beneficial, as sprays are not needed.
Discuss other diseases
Viruses:
- Most do not kill the vine but reduce its ability to function and can dramatically reduce yield and quality
- They are usually spread via cutting or nematodes
- There are no treatments
- Can only be eradicated by digging up vines and sanitising the land
Bacterial diseases:
- Reduce grape quality and quantity, some can kill the vines
- Spread by small insects called sharpshooters
- Cannot be treated or cured
- Can be prevented with strict quarantine procedures and interrupting the lifecycle of the sharpshooters
- Can only be eradicated by digging up vines and sanitising the land
What are the different emerging viticultural practice
The use of man made sprays/chemicals to control pests and diseases and increased use of fertilisers increased concern due to damages the environment
- Sustainable agriculture
- Organic agriculture
- Biodynamic agriculture
Discuss Sustainable agriculture
- Man-made chemicals are not prohibited
- Growers are encouraged to pay closer attention to pest lifecycles and weather, in order to prevent diseases and outbreak before it occurs
- Use of Integrated Pest Management (encouraging the presence of the pests’ natural predators)
Discuss Organic agriculture
- Similar to sustainable agriculture, but with only a limited number of the traditional treatments against pests and diseases and in smaller quantities
- Accreditation is required to display organic credentials
- All vineyards need to undergo a period of conversion before they can be certified
- Inconsistent. standards due to accreditation boards varying standards - except all need to undergo a period of conversion before they can be certified
Discuss Biodynamic agriculture
- Founded by Rudolf Steiner and Maria Thun
- Adopts organic practices but also incorporates philosophy and cosmology
- Vineyard soil is seen as part of a connected system with Earth, the air and other planets
- Practitioners adapt growing practices in coincidence with cosmic cycles
- Homeopathic remedies called treatments are used as fertilisers, disease treatment and pest deterrent.
- Need to be certified to officially become biodynamic
Describe the vineyard cycles and timing for northern hemisphere (southern)
- Budburst: March - April (September - October)
- Shoot & Leaf Growth: March - May. (September - November)
- Flowering and fruit set: May - June (November - December)
- Véraison: July - September (January - March)
- Harvest: September - October (March - April)
- Winter dormancy: December - March (July - September)
Describe budburst
- Budburst: March - April (September - October)
- Usually begins at 10C but it depends on the grape variety
- Example of early-budding varieties: Chardonnay and Pinot Noir
- Example of late-budding variety: Cabernet Sauvignon
- Biggest risk to during budburst is spring frost
- Spraying begins are budburst
Describe ‘early shoot and leaf growth’
- Shoots grow rapidly until the vine flowers
- Initially fuelled by stored carbohydrate reserves
- Energy provided partially by leaves as they grow and begin to photosynthesise
- Part of the vine cycle when water and nutrients are the most important
- If practiced, shoot-tying takes place during this phase
Describe Flowering and fruit set
Inflorescences start florwering and the vines needs:
- Warm temperatures
- Plenty of sunshine
- Little to no rain else pollination may be disrupted, reducing fruit-set
Fruit set occurs when a flower develops into a grape.
- Not every flower becomes a fruit and unpollinated flowers drop off
- Coulour is when more flowers than normal fail to fertilise
- Millerandage: grapes form without seeds and remain small
- Usually they are cause by cold, cloudy or rainy weather during pollination and they reduce yields
- Spraying continues as necessary
What is generally the cause of Millerandage and Coulure?
Cold, cloudy or rainy weather during pollination
Describe veraison
- Period of 6 - 8 weeks
- It is the point at which grapes begin to ripen
- Skin changes colour (R turn purple, W: translucent or gold)
Describe Ripening
- Grapes swell and fill with water
- Sugar levels rise,
- Acid levels drop
- Colour pigments and flavour compounds accumulate
- Tannins develop
- Warm and sunny conditions is required with mild water stress to inhibit shoot growth and encourage grape ripening
- Monitoring in the rise in sugar levels happens during ripening process
- The grapes will develop their signature flavours
- Tannins in the grape skins become less bitter and astringent
- If necessary the following happens:
- Summer pruning - to remove excess foliage, ensuring the canopy remains open
- Green harvesting - to control yield and improves fruit quality
Describe harvest
- Starts when the vigneron believes the grapes have the exact qualities needed to create the desired style of wine Ideally need dry condition.
- Poor weather conditions may cause a winemaker to bring the harvest forward
- Excess rainfall before harvest can cause the grapes to swell, diluting flavour
- Chances of rot are increased too
- Spraying must finish a reasonable time before harvest to ensure there are no harmful residues in the wine
Describe winter dormancy?
- Shoots become woody
- Leaves fall
- The vine stores carbohydrates in its roots
- In continental climates winter freeze can kill buds and the vine itself in extreme cases V
- ine can be protected by piling earth up around the vine Winter pruning happens
What dictates when the ideal balance of sugar, acid, flavour and tannin is reached in a grape?
- Grape variety
- Climate
- Style/quality of wine being produced
What does hail do to crops?
Destroys them
Why do winemakers need to coordinate the arrival of fruit at the winery?
To make sure it is not suddenly overwhelmed with fruit it does not have the capacity to process
Name the main factors which dictate how a vineyard should be harvested
- How the vineyard is planted
- Labour availability/cost
- Vineyard topography
- Weather conditions
- Winemaking choices
How must premium wine be harvested?
By machine or hand
How do machine harvesters work?
By shaking the trunk of the vine and collecting the ripe berries as they fall off, leaving the stalks behind
What are the major disadvantages/difficulties of machine harvesting?
- They are unselective, often collecting unhealthy, damaged and unripe grapes, as well as bits of leaf, insects and other contaminants
- They can only be used on flat or gently sloping land
- They are best suited to varieties whose grapes are not easily damaged and come away easily from their stems
- They cannot be used for wines whose grapes need to be picked in whole bunches
What is MOG?
Matter Other than Grapes
- Unwanted contaminants collected often by machines during harvest
- They can be removed at the winery during sorting
- Some harvesting operations are too large making sorting impossible
What is arguably the biggest advantage of machine harvesting?
Speed
- The vintage may be threatened by bad weather
- Some varieties may become overripe very quickly
Machines can work overnight
- Grapes can be brought back to the winery when they are still cool
- If they are cool, money is saved on cooling them before fermentation
- It slows down the process of oxidation
Name two wines whose grapes need to be picked in whole bunches
Champagne Beaujolais
Describe hand harvesting
It involves pickers cutting off individual bunches of grapes with secateurs
List the main advantage/disadvantages of hand harvesting
Advantage:
- It allows grape selection to take place in the vineyard
Disadvantage
- It is slower
- It is more labour-intensive
- It can be more expensive
For which wines is hand-harvesting essential? Why?
- Those requiring grapes affected by noble rot
- Onset and level of rot can vary between bunches
- Less damage occurs
- Grapes can be further protected from damage by transporting them in shallow, stackable trays
Unlike machine harvesting, the…are retained
Stems
Why is it good that hand harvesting allows stems to be retained
Whole, intact bunches can produce a very clean, pure juice when pressed during white winemaking It is essential for whole-bunch fermentations in red winemaking
Give three examples of places where machine harvesting is not possible. Give the reason
- Douro
- Mosel
- Northern Rhône
