Canopy Management

Question 1

Aims of Canopy management

Answer 1

1. Maximise the effectiveness of light interception by the vine canopy
2. Reduce the shade within the canopy
3. Ensure that the microclimate for the grapes is as uniform as possible so that grapes ripen evenly
4. Promote balance between the vegetative and reproductive functions of the vine
5. Arrange the vine canopy to ease mechanisation and/or manual labour
6. Promote air circulation through the canopy to reduce incidence of disease.

Question 2

Purpose of maximising leaf surface area exposed to sunlight.

Answer 2

• Increases the vine’s photosynthetic capacity
• Increases the vine’s ability to ripen larger yields

Question 3

Problems associated with dense canopies.

Answer 3

Poor air circulation

Higher humidity within the canopy

Suitable conditions for fungal diseases to develop

Fungicides will have less penetration into the canopy

Question 4

Seven effects of good canopy management on grape quality due to increased exposure to sun and heat.

Answer 4

1. Increased sugar levels
2. Increased tannin levels and riper tannins in grape skins (polymerisation of tannins = less bitter)
3. Enhanced colour in black grape skins (anthocyanins)
4. Decreased malic acid (warmer temperatures lead to more malic acid being broken down in cellular respiration)
5. Increased levels of favourable aroma precursors (Terpenes)
6. Decreased methoxypyrazines
7. Reduction of fungal disease pressure

Question 5

Five factors that determine the ideal amount of fruit.

Answer 5

1. Climate
2. Water and nutrients
3. Grape variety
4. Choice of rootstock
5. Desired wine style

Question 6

At what stage of the annual vineyard activities can the number of shoots on a vine be controlled?

Answer 6

Winter pruning

Summer pruning

Question 7

Define yeald

Answer 7

A measure of the amount of fruit produced. Either presented as weight per vine (kg/vine) or weight per unit of area. (tonnes/hectare).

Question 8

6 main canopy management techniques:

Answer 8

1. Site assessment to determine the ideal grape variety, rootstock vigour, planting density and row orientation
2. Vine training
3. Winter pruning
4. Vine trellising
5. Overall plant vigour management (nitrogen fertilisation, irrigation, cover cropping etc.)
6. Summer pruning

Question 9

What vineyard operations are performed during Summer Pruning?

Answer 9

• shoot removal
• shoot positioning
• pinching
• shoot trimming
• leaf removal
• crop thinning/green harvesting

Question 10

How would one plant vines that are high in vigour?

Answer 10

• Will need greater within-row spacing to grow and be in balance
• Planting these vines too close together could lead to overlapping canopies and increased shading, reducing ripeness and quality.

Question 11

How would one plant vines in dry regions without irrigation?

Answer 11

Low density so that the roots can spread out, without competition, in search for as much water as possible.

Question 12

General rule of between-row spacing?

Answer 12

Vine rows should be planted far enough apart so that one row does not shade the next.

The width of any machinery that might be used must also be considered

Question 13

What orientation generally provides the most even sunlight exposure through the canopy?

Answer 13

north-south

Question 14

Conditions in the afternoon are usually warmer than those in the morning so what might a grape grower do with north-south orientation rows?

Answer 14

Grape bunches on the west side of the canopy (which are exposed to the afternoon sun) may require more shading from leaves to protect them from sunburn.

Question 15

What effect does prevailing winds have on row orientation?

Answer 15

Grape growers may choose to orient the rows at a 90° angle to the direction of the wind to provide most protection from it.

Question 16

What is Vine Training?

Answer 16

Typically refers to the shape of the permanent wood of the vine.

Question 17

Two main categories of vine training?

Answer 17

1. head training
2. cordon training

Question 18

Describe low-training of a vine.

Answer 18

• The vine trunk is short
• Benefit from heat retained by the soil
• Provide greater protection from wind

Question 19

Describe high training of a vine.

Answer 19

• The vine trunk is long
• Better avoid frosts
• Make manual interventions (e.g. harvesting) easier

Question 20

Describe Head Training.

Answer 20

• These vines have relatively little permanent wood.
• The permanent wood usually consists of the trunk and head of the trunk.
• They can either be spur-pruned or replacement cane-pruned.

Question 21

Describe Cordon Training.

Answer 21

• These vines typically have a trunk and one or more permanent horizontal arms of permanent wood, typically called ‘cordons’.
• They are usually spur-pruned.
• Cordon training takes longer to establish than head training due to the amount of permanent wood.

Question 22

Define winter pruning.

Answer 22

The removal of unwanted parts of the vine in winter to determine the number and location of buds that will form.

Question 23

Describe spur pruning.

Answer 23

• Spurs are short sections of one-year-old wood that have been cut back to only two or three buds.
• Spurs can either be distributed along a cordon (cordon training) or around the top of the trunk (head training).

Question 24

Define and describe “canes”.

Answer 24

• Canes are longer sections of one-year-old wood and can have anything between 8 and 20 buds.
• They are typically laid down horizontally and need tying to a trellis for support and positioning.

Question 25

Define and describe trellising.

Answer 25

• Permanent structures of posts and wires that help to support and position the vine’s shoots
• Vine’s tendrils will naturally curl around the trellis wires and help keep the canopy in place.
• The grape grower will also tie in branches and shoots to the trellis as necessary.

Question 26

Define bush vines.

Answer 26

No trellising

Head-trained

Spur-Pruned

Question 27

Climate where bush vines are popular and why?

Answer 27

Hot and sunny regions

Dry conditions

The shade created is beneficial to avoid sunburn

Dry conditions inhibit disease in a potentially humid fruiting zone

Question 28

Advantages and disadvantages of trellised training systems?

Answer 28

1. Maximise light interception
2. Increase air flow through the canopy (reducing risk of fungal disease)
3. Aids mechanisation, by positioning the fruit in one area
4. expensive to establish and requires mantainance

Question 29

Describe Vertical Shoot Positioning (VSP).

Answer 29

• The vine’s shoots are trained vertically and are held in place onto the trellis forming a single narrow canopy.
• Best suited to vines with low or moderate vigour.

Question 30

Describe Guyot training.

Answer 30

Describe Guyot training.

• When VSP is used on replacement cane-pruned vines
• Single: one cane retained
• Double: two canes retained

Question 31

Four split canopy systems.

Answer 31

1. Geneva Double Curtain
2. Lyre
3. Scott-Henry
4. Smart-Dyson

Question 32

Three aims of summer pruning.

Answer 32

• Enhancing grape ripening
• Reducing chance of fungal disease
• Making the vineyard easier to manage.

Question 33

Describe debudding.

Answer 33

AKA debudding

• Removal of excess buds

Goals:

1. manage vine balance and yields (quality, law)
2. to remove buds that are poorly positioned (downward facing, close together)
3. remove buds of non-fruit bearing shoots (competition)

Question 34

Describe shoot removal.

Answer 34

• Removal of shoots, often laterals, that are infertile or poorly positioned (e.g. too close together or low down on the trunk)
• Help to maintain a well-organised, open canopy.

Question 35

Describe shoot positioning.

Answer 35

The shoots are tucked into the trellis wires in an organised manner to better organise the canopy and facilitate mechanisation.

Question 36

Describe pinching.

Answer 36

• Removes the shoot tips at flowering
• Improve fruit set.

Question 37

Describe shoot trimming.

Answer 37

• Cutting shoots to limit growth and reduce canopy thickness
• Enhances fruit ripening by reducing competition for carbohydrates between the shoot tips and fruit
• Lowers disease pressure through better air circulation and improved spray penetration.

Question 38

Describe leaf stripping.

Answer 38

• Removing leaves
• Reduce shading of fruit and hence enhance ripening
• Lower disease pressure through better air circulation and improved spray penetration.

Question 39

Describe crop thinning or green harvesting.

Timing?

Answer 39

• Removal of bunches of grapes
• Increase ripeness of those grapes left on the vine.

Timing of green harvesting.
- near véraison to enhance ripening.
- In cases where fruit ripening is uneven (e.g. because of uneven budburst, frost or the presence of bunches on lateral shoots), the least ripe bunches of grapes may be removed to improve uniformity of ripening.