Level 4 D1 Chap 7 - Canopy Management

Question 1

What are the aims of canopy management?

Answer 1

• Maximise effectiveness of light interception by canopy
• Reduce shade on grapes
• Uniform microclimates for grapes for even ripening
• Balance between vegetative and reproductive functions in the vine
• Ease of harvesting (mechanised or by hand)
• Promote air circulation to reduce disease

Question 2

What impact does sunlight have on different compounds in a ripening grape?

Answer 2

• increases sugar through photosynthesis
• increases tannins
• increases polymerisation of tannins
• enhances anthocyanins in black grapes
• decreases Malic acid through grape respiration
• increases favorable aroma compounds & precursors (e.g., terpenes)
• decreases methoxypyrazines

Question 3

What are the implications on the following season from a too low yield in a year? What is this called?

Answer 3

The following year the vine can be too vigorous, reducing bud fruitfulness and encouraging vigorous growth.

This is called under-cropping.

Question 4

What are the implications on the following season from a too high yield in a year? What is this called?

Answer 4

Trunks and roots can be exhausted of carbohydrate, weakening vine growth the following year.

This is called over-cropping.

Question 5

What is a high planting density and a low planting density?

Answer 5

low - 100s of vines per hectare

high - 10,000 vines per hectare

Question 6

What drives the choice of vine density when planting?

Answer 6

• vigour of the variety: low vigour can be more closely planted that high vigour
• trellising techniques to be used
• what access is needed between vines (mechanization)
• local laws may put limits in place

Question 7

What factors determine the choice of vine training, pruning and trellising techniques?

Answer 7

• vine vigour
• site topography
• mechanisation requirements

Question 8

What is vine training?

Answer 8

• shaping of permanent wood (head or cordon training?)

- low or high trained?

Question 9

What are the common types of vine training?

Answer 9

Head training - just a trunk
Cordon training - arms on a trunk

Both can be high (avoid frost, easier harvesting) or low (benefit from heat retained by soil and withstand wind)

Question 10

What are the common types of pruning?

Answer 10

Spur pruning - 2-3 buds

Replacement cane pruning 8-20 buds

Question 11

Describe an untrellised vineyard. When is this used? What is it called?

Answer 11

Called bush vines - simple and inexpensive.

Usually head trained and spur-pruned.

Normally practiced in sunny regions to keep grapes shaded, and in dry regions as vigour is limited (otherwise too much canopy grows) and also where fungal diseases are not an issue.

Not suitable for mechanisation.

Question 12

What is the most common trellising system?

Answer 12

VSP: Vertical Shoot Positioning - best for low/moderate vigour

Question 13

What trellising is used for vigorous vines?

Answer 13

GDC - Geneva Double Curtain
Lyre
Scott-Henry

Question 14

What is the Scott-Henry technique?

Answer 14

Double level VSP (vertical shoot positioning) for high vigour vines

Question 15

What is GDC?

Answer 15

The Geneva Double Curtain training, splits the canopy horizontally

Question 16

List at least 5 summer pruning techniques

Answer 16

Disbudding
Shoot removal
Shoot positioning 
Pinching, during fruit set
Shoot trimming 
Leaf removal
Crop thinning/green harvesting

Question 17

Why carry out summer pruning?

Answer 17

• Reduce competition between vegetation and grapes
• Increase sun/circulation for grapes
• Remove grapes ripening out of sync

Question 18

What does the “right” amount of fruit (“balanced yield”) depend upon?

Answer 18

• growing environment
• the vine itself (grape variety)
• rootstock
• presence of disease
• age of vines
• wine style being produced

Question 19

What are the canopy management techniques available?

Answer 19

• vine training
• winter pruning
• vine trellising
• overall plant vigor management
• summer pruning