Ch6 Vine Management Flashcards
What are the three main considerations a producer may need to make when choosing a site?
Environmental conditions
Business considerations
Grape variety
Which environmental conditions does a producer have to consider?
Average temperature Rainfall Sunlight Soil fertility Drainage
What business considerations must be made by a producer when selecting a vineyard site?
Proximity to utility infrastructure (power, water etc.)
Availability of a vineyard workforce
Accessibility for machinery
Cost of land
What must a producer consider regarding grape variety when selecting a site?
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
Why is irrigation allowed in some places after new vines have been planted?
To allow the vines to establish themselves
When does a vine’s first yield usually come?
In the third year after planting
At what age on average are vines usually replaced?
30 - 50 years
What is the main factor that makes old vines desirable?
They give a greater concentration of flavours
What are the potential disadvantages to growing an old vine?
Lower yield
Susceptibility to disease
For how long is a vineyard typically left fallow after the vines are dug up?
Three or more years
What are the four main techniques used to manage a vine?
Training
Pruning
Trellising
Planting density
The grower will adapt the four main vineyard management techniques to suit the availability of these resources:
Temperature
Sunlight
Water
Soil nutrients
Name a practical consideration a grower may have to make when establishing a vineyard
Use of machinery
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
What are the two principal branches of vine training?
Head training
Cordon training
Both head training and cordon training can be…to benefit from heat retained by the soil or…to avoid frosts
Low trained
High trained
Describe a head-trained vine
They have very little permanent wood
Some have only a trunk
Some have a few arms protruding 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
Describe a positive and negative of cordon training a vine
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
Cordon training can also be used to create…
Big vine structures
What is pruning?
The removal of unwanted leaves, canes and permanent wood
What is the purpose of pruning?
It shapes the vine and limits its size
When does pruning typically take place?
Every summer and every winter
What is the main purpose of winter pruning?
To determine the number and location of buds that will form shoots in the coming season
Why is it important to ensure that buds are not too close together?
To help with canopy management
What are the two styles of winter pruning?
Spur pruning
Replacement cane pruning
Describe spur pruning
Spurs are either distributed along a cordon or around the top of the trunk
Describe replacement cane pruning
Typically one or two canes are retained
Each cane is tied horizontally to the trellis for support
Most common on head-trained vines
What are the two main disadvantages to replacement cane pruning?
It requires a large, skilled workforce to choose suitable canes and train them
It is more complex than spur pruning
What is the alternative name for replacement cane pruning?
Guyot training
What does summer pruning involve?
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
What is a vine’s ‘canopy’?
All green parts of the vine
What is a grower’s most important concern when considering canopy management?
Whether to trellis
What is a trellis?
A permanent structure of stakes and wires, used to support any replacement canes and the vine’s annual growth
What is a bush vine?
The vines do not have a trellis system and the shoots can hang down as far as the ground
They are head-trained and spur pruned
What kind of climate is a bush-trained vine most suited to? Give two examples..
Warm/hot, dry, sunny
Southern Rhône
Barossa Valley
Why is bush-training best suited to a hot, sunny environment?
The extra shade helps to protect the grapes
Why is bush-training unsuitable for cool or wet regions?
The shade can impede grape ripening
Lack of airflow can promote disease
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
What kind of vines are not suitable for mechanical harvesting?
Untrellised
Give another name for bush-training
Gobelet
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 three important reasons for canopy management?
To control the amount of sunlight that gets to the canopy
To improve air circulation
To aid mechanisation
How does trellising aid mechanisation?
It separates leaves from grapes
What is the secondary benefit of separating leaves and fruit?
Spraying of insecticides and fungicides is more effective
What is the most widely used trellising system?
Vertical Shoot Positioning (VSP)
Which pruning system can VSP be used with?
Either
Describe VSP
Shoots are trained vertically and tied in place onto the trellis
How can VSP be adapted in hot, sunny regions?
Rather than tying the top of the shoots, allowing them to flop over, providing some shade for the fruit
Why might a grape grower choose adapted VSP over bush vine training?
It allows for mechanisation
How is planting density measured?
It is the number of vines planted in a given area
What is a hectare?
An area enclosed by a square with 100m sides
What is the rough range of planting densities?
1,000 - 10,000 vines per hectare
How does an acre relate to a hectare?
One acre is approximately 0.4 hectares
Name a very important set of criteria when deciding on planting density
Availability of nutrients and water
Explain the most advantageous planting density considerations for areas with limited water availability
Low planting density allows each vine’s roots to take up water from a larger volume of soil without any competition
Explain the effect on a vine of having low levels of nutrients but sufficient water?
It can still grow vigorously and produce lots of vegetative growth in preference to fruit
In a situation where a vine has plenty of rainfall/water, what may a grower do to reduce vigour?
Plant at high density to provide competition for resources
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 two human-controlled factors in the vineyard which can affect vine vigour?
Planting density
Pruning
What is the problem for a winemaker when there is ample rainfall and very fertile soils?
Vines can be overly vigorous
Pruning and planting density are often not enough
What is an additional practice which can be used when planting density and pruning aren’t enough to reduce vigour sufficiently?
Vines may be planted at low density with multiple cordons or canes
What is yield?
A measure of the amount of grapes produced
In what units may yield be measured?
Weight
Volume
What are the three principal reasons why a winemaker may need to know yield?
Legal requirements
Contractual obligations
Predicting tank space
How may yield be approximately predicted?
By observing the number of buds left on a vine after winter pruning
Which factors may make predicting yield difficult/inaccurate?
Frost damage
Poor fruit set
Pests and diseases
How may yields be reduced by the winemaker?
By removing immature grapes shortly after véraison
What is the process of removing immature grapes after véraison called?
Green harvesting
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 effect does yield have on grape quality?
No discernible effect
What are the broad potential effects of pests and diseases?
Reduced yield
Reduced fruit quality