6 - Vineyard Management Flashcards
The vineyard cycle (1+2+2+2+1+1)
- Budburst
- Early Shoot & Leaf Growth
- Flowering & Fruit Set
- Véraison & Berry Ripening
- Harvest
- Winter Dormancy
Budburst (period, N&S)
March - April
September - October
Budburst (what happens, temp, grape ex)
Buds swell and burst, growing into new shoots.
Generally begins when mean daily temp >10C (dep. on gr.var.)
Chard & PN: early-budding (bud at relatively low temp)
CS: late-budding
Early Shoot & Leaf Growth (period, N&S)
March - May
September - November
Early Shoot & Leaf Growth (what happens, fuelled, needs)
Shoots grow rapidly until the vine flowers.
Fuelled by carbohydrate reserves stored over winter and photosynthesis later.
Needs a good supply of water and sufficient nutrients early in the season.
If practised: Shoots are tied to trellis to ensure the canopy remains open.
Flowering & Fruit Set (period, N&S)
May - June
November - December
Flowering & Fruit Set (what happens, needs, dangers)
Inflorescences start flowering.
Needs warm temp., plenty of sunshine and little or no rain.
Fruit set: when a flower starts to develop into a grape.
Unpollinated flowers drop off.
Coulure & Millerandage if cold, cloudy or rainy weather during the pollination period –> reduce yields.
Coulure
If more flowers than normal fail to fertilise
Millerandage
Grapes form without seeds and remain small
Véraison and Berry Ripening (period, N&S)
July - September
January - March
Véraison and Berry Ripening (what happens, needs, vy-man.)
- 6-8 weeks after fruit set
- Véraison: the grapes begin to ripen, gr. changes colour
- Véraison-Harvest: grapes swell and fill with water
- Ripening: grape sugar levels rise, acid levels drop, colour pigments and flavour compounds accumulate, tannins develop.
- Ideal: warm and sunny conditions. Mild water stress inhibits shoot growth and encourages grape ripening.
- If required/practised: summer pruning to remove excess foliage. Green harvesting shortly after véraison.
Véraison
The point at which the grapes begin to ripen. Skin changes colour.
Berry ripening
- colour change
- sugar increase
- acid decrease
- develop signature flavours
- tannins become less bitter & astringent
Harvest (period, N&S)
September - October
March - April
Harvest (ideal cond., if spraying)
Ideally: dry. Excell rainfall before harvest can cause grapes to swell, diluting the juice, and due to damp conditions it can increase the risk of rot.
Spraying must hav finished early enough to ensure that there are no harmful chemical residues in the wine.
Winter Dormancy (period, N&S)
December - March
July- September
Winter Dormancy (what happens, hazard)
- Shoots become woody (canes).
- Leaves fall and the vine stores its reserves of carbohydrates in its roots.
- Winter freeze can kill buds and in extreme cases the vine itself (continental climates)
- Winter pruning takes place.
Considerations regarding site selection
- Environmental conditions
(average temp., rainfall, sunlight hours. Fertility and drainage of soil. Will influence the choice of grape variety, ideal planting density, systems of training and trellising) - Business considerations
(proximity of a vy to the utility infrastructure, vy workforce, accessibility of a site for machinery, cost of the land –> financial viability) - Grape variety
(climatic conditions, demand for the grapes, legal restrictions)
Planting/replanting (cycle)
- cleared of vegetation
- test fertility of the soil –> fertilisers to correct deficiencies
- plant vines (usually pre-grafted) - hand or machine
- plastic sleeves (protect from animals), irrigation (help establish)
- first yield: 3rd year after planting
- replaced between 30-50 yo
- vy left fallow (unplanted) for more than 3 years (recover)
‘old vine’
conc., lower yield, incr. susceptible to disease
Managing the vine (4 main techniques)
The grape grower will …
- training
- pruning
- trellising
- density
The grape grower will
- adapt these practices to suit the vineyard’s resources (temp., sunlight, water, soil nutrients)
- take into account practical considerations (use of machinery)
The grape grower’s goal
maximise the production of fruit at the desired quality level as economically as possible
Vine training (def., main cat.)
The shape of permanent wood of the vine.
1. Head training
2. Cordon training
Low-trained or high-trained
Head training
Relatively little permanent wood. Only trunk, or a few short arms.
Either spur-pruned or replacement cane-pruned.
Cordon training
A trunk with one or more permanent horizontal arms or ‘cordons’.
Usually spur-pruned.
Takes longer to establish.
Makes mechanisation in the vy easier to achieve (ie machine harvesting)
Normally one or two cordons, can also have four or more.
Vine Pruning
- Removal of unwanted leaves, canes and permanent wood.
- Shapes the vine and limits its size.
- Every winter and summer.
Winter Pruning (main purpose and 2 styles)
Determine the number and location of the buds that will form shoots in the coming growing season.
1. Spur pruning
2. Replacement cane pruning
Spur pruning
- Short sections of one-year-old wood that have been cut down to only two to three buds.
- Either distributed along a cordon of permanent wood (cordon training) or around the top of the trunk (head training)
Replacement cane pruning
- Canes are longer sections of one-year-old wood and can have between 8 and 20 buds.
- Typically only one or two canes are retained and each cane is tied horizontally to the trellis for support.
- Most often seen on head-trained vines.
- More complex than spur pruning and requires a large skilled labour force to choose suitable canes and train them.
- Sometimes referred to as Guyot training (Single Guyot, Double Guyot)
Summer pruning
- Involves trimming the canopy to restrict vegetative growth and direct sugar production to the grape.
- Can also involve leaf stripping so that bunches of grapes have optimum exposure to sunshine.
Trellising
Permanent structures of stakes and wires that are used to support any replacement canes and the vine’s annual growth.
Untrellised vy (what, where, how)
- bush vines: head-trained, spur-pruned. Best suited to warm/hot, dry, sunny reg. (South. Rhône, Barossa V.)
- gobelet: shoots tied together at the tips (expose bunches to air & sunlight) –> Beaujolais
- not suitable for mech. harv.
What is canopy management?
- Line of posts joined by horizontal wires.
- Canes & shoots tied to the trellis
3 important reasons for canopy management and trellising
- control amount of sunlight (open vs shaded)
- air circulation
- mechanisation (spraying, harvesting)
Most widely used trellising system
Vertical Shoot Positioning (VSP)
- What is VSP?
- What pruning is used?
Describe how it is done and it’s advantage
Vertical Shoot Positioning
- repl. cane pruned or spur pruned
- trained vertically and tied in place onto the trellis forming a single narrow canopy
- tops of shoots tied or free to flop over (shadow)
- mechanical harvesting can be used
Planting density (def., factors infl.)
- The number of vines that are planted in a given area (ie vines per hectare, 100x100m)
- Vary from 1000 - 10.000 vines per hectare
- Availability of nutrients & water infl. decision regarding pl.dens.
1. limited water avail.: low pl.dens.
2. low nutr. & sufficient rainfall: high pl.dens., corr number of buds
3. high nutr. & suff rf: high pl.dens., multiple cordons/canes
Yields
Measure of the amount of grapes produced (weight or volume)
Why is it important to manage & predict yields?
- legal requirements
- contractual obligations
- tank space
How to predict yields
Estimate from the number of buds left on the vine after winter pruning
(but frost damage, poor fruit set and pests & diseases can dramatically reduce the final figure)
How to reduce yields, and why is it risky?
- Green harvesting: removing immature grapes shortly after véraison.
- 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 –> increase yield and dilute flavours
Yields and quality (trad vs fact)
- Traditionally: thought that high fruit quality could only be achieved by low yields of grapes
- Very hard to make any solid link between quality and yield
Types of pests and diseases (5+3+2)
- Pests (Phylloxera, Nematodes, Birds & mammals, Insects)
- Fungal diseases (Downy & powdery mildew, Grey rot)
- Other diseases (Viruses, Bacterial diseases)
Pests (4)
- Phylloxera
- Nematodes
- Birds and mammals
- Insects
Nematodes
- microscopic worms
- attack roots
- may transmit viruses
- preventing better than cure (sanitising soil before replanting, resistant rootstocks)
Fungal diseases (types, treatment)
- Downy & powdery mildew
- Grey rot
How to controll/treat:
1- Fungicides
- usually by tractor
- more needed in maritime cl
- must stop close to harvest
2- Canopy management
- open vine canopy –> greater air flow
Downy & powdery mildew
- warm, humid environments
- attack green parts
- grapes lose fruity flavours & can give mouldy bitter taint
Traditionally
- DM: Bx-mixture, copper-based spray
- PD: Sulphur-based spray
- What is Grey rot
- conditions
- Attacks
- Grape flavours & colour
- Good rot
- Botrytis cinerea
- damp conditions
- attack grapes
- taint grape flavours, colour loss in black grapes
- certain white grapes & conditions –> noble rot
Viruses
- limiting the vines ability to function - do not kill (usually)
- reduce yield & quality
- highly contagious & persistent
- spread by nematodes or cuttings
- no treatment or cure
- digging up & sanitising
Bacterial diseases
- reduce yield & quality, some kill the vine
- typically spread by small insects called sharpshooters
- no treatment or cures
- strict quarantine procedures & interrupting life cycle of ss
- digging up & sanitising
Viticultural practices
- Sustainable agriculture
- Organic agriculture
- Biodynamic agriculture
Sustainable agriculture
- restricted use of man-made chem. (not prohibited)
- understand lifecycles of vy-pests & monitor weather forecast –> predict & prevent before outbreak
- fewer (timed) applications
- integrated pest-management –> predators of cert. pests may be encouraged to live in the vy
- vineyard biodiversity –> habitat for predators of pests & provide nutrients for vines
Organic agriculture
- only a limited number of more trad. treatments is allowed, only small quant.
- accreditation is required from an organic certification body to show organic credentials on the label
- many cert. bodies: similar principles, slightly diff. standards
- all vy must undergo a period of conversion working to org. standards before it can be certified
Biodynamic agriculture
- Rudolf Steiner & Maria Thun
- organic practises, but also philosophy & cosmology
- vy soil part of a connected syst. w the planet Earth, the air & other planets
- grape growing practices to coincide with the cycles of planets, moon & stars
- homeopathic remedies (‘preparations’) used to fert. soil, treat dis. & ward off pests
- certification bodies
Harvest
- monitoring grape sugars to track the ripening process
- ideal balance depend on: grape varity, climate, style & quality
- weather & winery capasity
- hand vs machine
Hand vs machine-harvest.
Decision depend on:
- how the vy is planted
- labour availability & cost
- topography of the vy
- weather conditions
- winemaking choices
Machine Harvesting (how, plus & minus)
- shaking the trunk & collecting ripe berries falling off
Plus
- speed (essential if bad weather or grapes that over-ripe quickly)
- work through night –> cooler, saves money & energy, sloves down oxidation
Minus
- not selective, (unhealthy, unripe, damaged grapes + MOG (sorting at winery if possible)
- can only be used on flat & gently sloping land
- best suited for grapes that is not easily damaged
- not whole bunches
MOG
matter other than grapes
(leaf, insects and other contaminants)
Hand Harvesting (how, plus & minus)
- Individual bunches with secateurs
Minus:
- Slower and more labour intensive –> more expensive
Plus:
- Allow grape selection in vy (essential for noble rot)
- Less damage
- Stems retained –> Intact grape bunches –> produce clean, pure juice
- Whole bunch fermentations
- Only option on steep slopes
