Canopy

Question 1

The 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 maximizing the leaf surface area exposed to sunlight

Answer 2

• Increases the vine’s photosynthetic capacity (compared to a vine with a dense, shaded canopy)
• Increases the vine’s ability to ripen larger yields

Question 3

Problems associated with dense conopys

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
3. Enhanced colour in black grape skins
4. Decreased malic acid
5. Increased levels of favourable aroma precursors
6. Decreased methoxypyrazines
7. Reduction of fungal disease pressure

Question 5

Define optimal crop load.

Answer 5

The maximum yield of grapes that will allow for the required grape composition for the desired wine style and quality.

Question 6

Describe a balanced cycle of canopy management.

Answer 6

After veraison, sugars and other compounds needed for growth are allocated to fruit development rather than shoot growth. With less shoot growth, the canopy is less likely to become dense and shaded. This lease to higher quality fruit and enhanced bud fruitfulness the next year. The balanced cycle continues.

Question 7

Describe a vegetative cycle of canopy management.

Answer 7

Low yields of fruit can lead to high vigour of shoots and leaves.

The shoots and leaves compete for sugar, negatively impacting fruit development.

This leads to a dense canopy and lower quality fruit due to shading this will result in low yields the next year due to reduced bud fruitfulness the vine enters the vegetative cycle.

Question 8

Define undercropping.

Answer 8

The yield of fruit is too low for the vigour of the vine.

Question 9

Define overcropping.

Answer 9

If the yield of fruit is too high for the vigour of the vine.

Question 10

Five factors that determine the ideal amount of fruit.

Answer 10

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

Question 11

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

Answer 11

Winter pruning

Summer pruning

Question 12

Define yield.

Answer 12

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 13

What types of laws exist over yield?

Answer 13

In EU countries legislation may specify maximum yield per area of land.