Section 2 - Vineyard Management Flashcards
What 3 factors influence a vineyard site selection?
1) Environmental conditions
2) Business considerations
3) Grape variety
What environmental conditions are taken into account to influence a vineyard’s site selection?
- Average temperature
- Rainfall
- Sunshine
- Soil fertility
- Soil drainage
What business considerations are taken into account to influence a vineyard’s site selection?
- Proximity to utility infrastructure
- Availability of labour
- Accessibility to machinery
- Cost of land
Why are grape varieties taken into account when choosing a vineyard site?
Must suit the climatic conditions and there must be a demand for the grape.
In the EU there might be restrictions on what grapes are grown.
How is a vineyard planted?
1) New vineyards are cleared of vegetation
2) Young vines from the nursery are planted by hand or machine and are often protected against animals by plastic sleeves
3) Irrigation is sometimes allowed to promote growth
4) First yield is taken the third year following planting
When is a vineyard replanted?
30-50 years when they are replaced
Old vines are thought to produce premium grapes however the quantity and quality reduces over time.
Vineyards are left fallow (unplanted) for 3 years to allow recovery.
What are the 4 techniques used to manage the vine?
Training
Pruning
Trellising
Density of planting
What does training do to the vine and what are the two types?
Shaping the permanent wood of the vine. Both can be low trained to benefit from the heat from the soil or high trained to avoid frost.
1) Head Training
- Little permanent wood, some only a trunk. They can be spur pruned or replacement head pruned.
2) Cordon Training
Typically have trunks with one or more permanent horizontal arms or cordons.
What are the benefits and drawbacks of cordon training?
Can take longer due to more permanent wood
Sturdy permanent cordon makes machine harvesting easier
Vines normally have 1-2 cordons but can be used to make larger vine structures where shoots may only grow from 4-5 cordons
What is vine pruning?
Removal of unwanted leaves, canes and permanent wood.
When does vine pruning take place?
Summer and winter
Both determine the number and location of buds on the vine. This is key not to be too close together.
What are the two types of winter pruning?
1) Spur pruning
2) Replacement cane pruning
What is spur pruning?
Short sections of one year old wood is cut to 2-3 buds.
Spurs distributed along a cordon of permanent wood (Cordon training) or around the top of the trunk (head training)
What is replacement cane pruning?
Longer sections of one year old wood (8-20 buds).
One or two canes retained and tied horizontally to the trellis.
More complex and labour intensive to choose canes.
This is most common on head trained vines.
can be referred to as Guyot training (one can single, two canes double Guyot)
What does summer pruning involve?
Cutting the vegetal growth and directing sugar production to the grape rather than to the shoots and leaves.
This can involve leaf stripping to reduce the canopy and to give more optimal sunlight.
What is trellising and how does it aid canopy management?
Canopy - all green parts of the vine
Biggest choice in the vineyard is to decide whether to trellis the vine as this impacts how the vine grows.
What does an untrellised vineyard look like?
Shoots hang down as far as the ground (bush vines - typically head trained or spur pruned)
Best used in warm, dry and sunny regions where the shade protects the grapes (Eg: Southern Rhone, France, Barossa Valley in Aus)
Why are untrellised vineyards avoided in cool and wet regions?
Prevent disease due to lack of air flow
Shoots of head trained spur pruned vines are tied together at the tips to expose the vine to air and sunlight
eg: Beaujolais, France
How are untrellised vineyards harvested?
By hand - cannot be machine harvested
What does a trellised vineyard look like?
Posts joined together by horizontal wires.
The vine’s canes and shoots are tied to the trellis (canopy management)
Why is it important to trellis a vineyard?
1) Control sunlight coming into the canopy
2) Improve air circulation (important in wet climates)
3) Aid mechanisation in the vineyard
- Grapes and leaves separated eases harvesting and spraying of insecticides and pesticides
What does VSP stand for?
Vertical Shoot Positioning
What is VSP?
Technique that is widely used as it can be used with replacement cane or spur pruned vines.
The shoots are trained vertically and tied to the trellis to form a simple, narrow canopy. This keeps the canopy open, derated and shade free.
In hot regions, VSP is adapted so the top of shoots flop over to create a canopy to protect fruit. This technique is used instead of untrellised canopy management to allow machine harvesting.
What is density and how does it impact the vineyard management?
Number of vines planted in a given area.
Typically the number of vines per hectacre
Densities can be 1,000-10,000 vines per hectacre
One acre ~ 0.4 hectacres
What are the factors that affect density?
1) Very limited water availability
2) Low levels of nutrients and sufficient rainfall
3) High levels of nutrients and sufficient rainfall
4) Yields
How does limited water availability impact density in a vineyard?
Low rainfall and poor access to irrigation can mean low density is beneficial. The vine maximises the water in take and there is less competition for water.
How do low levels of nutrients and sufficient rainfall impact vineyard density?
Vines that are planted at high density in these conditions have to compete for nutrients, counteracting vigourous growth with too many nutrients.
Common in European vineyards.
Number of buds at winter pruning is key:
- Too few buds, grow too vigourously
- Too many bugs, not enough energy to grow, vine struggles to ripen
How do high levels of nutrients and sufficient rainfall impact vineyard density?
Fertile soils not favourable.
In the New World where these soils exist, high density planting is not enough.
Must use vines with multiple cordons or canes that are able to produce good quality grapes at high yields.
Explain how and why the yield of a vineyard must be carefully managed.
Yield = Amount of grapes produced - this must be managed and predicted.
Producers must abide by legal yield requirements (EU) and meet contractual obligations.
The yield estimate is made from the number of buds after winter pruning but frost, poor fruit set, pests and disease can reduce the yield.
If the yield is too high, this can be reduced by removing immature grapes after verasion (green harvesting). This is risky as the vine can compensate by increasing the size of the retained grapes (dilutes the flavour / retain yield to original size).
What happens when pests impact the vineyard?
Damage leaves which reduces photosynthesis and limits the vines ability to ripen grapes.
What are some examples of vineyard pests?
1) Phylloxera
2) Nematodes
3) Birds and mammals
4) Insects
What is a nematode?
Microscopic worms that attach roots and interfere with water and nutrient uptake. They can transmit vine viruses, prevention is better than cure.
To prevent, it is best to sanitise the soil before replanting and using resistant rootstock.
Why are birds and mammals a pest in the vineyard?
Create half eaten and crushed grapes increase the risk of fungal diseases.
Netting is best used to protect against birds.
Fencing is needed for rabbits, boar and deer.
Why are insects a pest in the vineyard?
Feed on grapes and leaves.
Use insecticides or integrated pest management to control.
Why are the two types of fungal diseases which pose a risk in the vineyard?
1) Downy and powdery mildew
2) Grey rot (botrytis cinerea)
How does downy and powdery mildew occur in a vineyard?
Funghi that thrives in warm, humid environments.
It impacts all green parts of the vine and the grapes.
This causes grapes to lose fruit flavour, leaving a bitter and mouldy taste.
How do you treat a vineyard that is threatened by mildew?
Powdery - treated with a sulfer based spray
Downy - treated with Bordeaux mixture copper spray
How does grey rot impact a vineyard?
Thrives in the damp and attacks the grapes specifically. Colour loss occurs in black grapes and this taints the flavour.
It can be beneficial in some white grape varieties (noble rot)
How can canopy management prevent against grey rot?
Trellising prevents damp conditions and the need to use chemicals to prevent the rot.
Chemicals are sprayed by the tractor and are required in maritime climates with high rainfall.
How do viruses impact the vineyard?
- Limit the ability for the vine to function, reduces yield and quality
- Contagious and persistent
- Spread via cuttings and nematodes
- No treatment or cures, eradicated by digging up the vines and sanitising the land
How does bacterial disease impact the vineyard?
- Reduces grape quality and quantity, can kill the vine
- Spread by small insects (sharp shooters)
- No treatments or cures
- Strict quarantine and interrupting lifecycle of sharp shooter only way to prevent the spread
- Dig up the vine and sanitise land to eradicate
What are the 3 main viticultural practices to reduce chemical use in the vineyard?1
1) Sustainable agriculture
2) Organic agriculture
3) Biodynamic agriculture
What is sustainable agriculture?
- Manmade chemicals are restricted, not prohibited
- Understand the lifecycle of pests and monitor weather to prevent pests and outbreaks
- Time applications of chemicals to reduce spraying
- Integrated pest management - predators of pests encouraged to control pest populations
- Range of plants in the vineyard rather than a monoculture to provide habitats for pests and nutrients for vines when mowed or ploughed into the soil
What is organic agriculture?
- Similar to sustainable agriculture but only a limited number of more traditional treatments for pests and diseases allowed in very small quantities
- Accreditation required from organic certification body to put organic credentials on the label
- Many bodies with different standards so some may have stricter conditions than others
- All must undergo a period of conversion working to organic standards before certification
What is biodynamic agriculture?
- Based on the work of Rudolf Steiner and Maria Thun
- Organic practises combined with philosophy and cosmology
- Vineyard soil as a connected system with Earth, air and other planets
- Adapt grape growing to coincide with cycles of plants, moor and stars
- Homeopathic remedies ‘preparations’ used to fertilise soil, treat diseases and ward off pests
- Certification bodies exist for biodynamic agriculture
At what point is a vineyard harvested?
VERASION = When the grapes have fully ripened, signalled by a change in skin colour. When sugar, acid, flavour, tannin and climate tie together for perfect ripeness.
As the grapes ripen, the sugar levels rise and the acid drops. Grapes develop flavour and tannins become less bitter.
Monitoring sugar levels key but no hard and fast rule of time to harvest.
Poor weather can bring the harvest forward.
Grapes can be hand or machine harvested depending on labour, topography of vineyard and weather etc.
What is machine harvesting?
Shakes the trunk of the vine and collect the berries as they fall
Leaves the stalks behind
Not selective (collects damaged grapes, can shake off other matter (MOG) such as leaves, insects and other contaminants which later have to be removed in the winery)
What is the main advantage of machine harvesting?
Speed
- Key when the harvest is threatened by poor weather or when grapes can go overripe quickly
- Work through the night so that cool grapes are sent to the winery
- Saves energy and money to lower grape temperatures pre-fermentation and slows oxidation which brings off flavours
What is the main disadvantage of machine harvesting?
Can only be used on flat / gentle slopes
Only suitable for grapes which cannot be easily damaged
Cannot be used for wines requiring whole bunches eg: Beaujolais and Champagne
What is hand harvesting?
Pickers cut individual bunches of grapes with secateurs
What is the advantage of hand harvesting?
Less damaged grapes / better quality of picking
Retains the grape stem - produce clean juice in white wine making which is key for fermentation in red
Helps pick grapes with noble rot
What are the disadvantages of hand harvesting?
Slow and labour intensive
Expensive
Only option in steep vineyards
eg: Douro in Portugal, Mosel in Germany, Northern Rhone in France
