Mastering Canopy Management Techniques

Question 1

The six main canopy management techniques:

Answer 1

1. site assessment to determine the ideal grape variety, rootstock vigor, planting density and row orientation
2. vine training
3. winter pruning
4. vine trellising
5. overall plant vigor management (nitrogen fertilization, irrigation, cover dropping, etc.)
6. summer pruning

Question 2

What operations are performed during summer pruning?

Answer 2

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

Question 3

Why is canopy management important when establishing a vineyard?

Answer 3

• choices regarding vine density will affect the vine training and trellising
• must be decided before planting anything

Question 4

What is vine density?

Answer 4

• the number of vines that are planted per hectare of vineyard
• range from a few hundred vines per hectare to over 10K

Question 5

How is the optimum vine density determined?

Answer 5

• the vigor of the vine (which is in turn influenced by natural resources and planting materials)
• the type of trellising system used
• what access requirements between the vines

Question 6

How would one plant vines that are high in vigor?

Answer 6

• 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 6

How would one plant vines that are low in vigor and VSP trained?

Answer 6

Can be planted very closely together within the row as the individual vines are relatively small

Question 6

How would one plant vines in dry regions without irrigation?

Answer 6

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

Question 7

What is the general rule of between-row spacing?

Answer 7

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

Question 8

What also needs to be considered when planning between-row spacing?

Answer 8

The width of any machinery that might be used.

Question 9

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

Answer 9

north-south orientation

Question 10

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 10

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

Question 11

What effect do prevailing winds have on row orientation?

Answer 11

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

Question 12

From an efficiency point of view, what row orientation is often the optimal option?

Answer 12

Orienting rows to the longest side of the vineyard

Question 13

What row orientation option is needed for vineyards on slopes at an angle of greater than 10%?

Answer 13

Need to be planted up and down the slope rather than across, or machinery may slip.

Question 14

What is vine training?

Answer 14

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

Question 15

Two main categories of vine training?

Answer 15

1. head training
2. cordon training

Question 16

Describe low-training of a vine.

Answer 16

• the vine trunk is short
• benefit from heat retained by the soil
• provide greater protection from wind

Question 17

Describe high training of a vine.

Answer 17

• vine trunk is long
• better to avoid frosts
• make manual interventions (e.g. harvesting) easier

Question 18

Describe head training.

Answer 18

• these vines have relatively little permanent wood
• permanent wood usually consists of the trunk and head of the trunk
• they can either be spur-pruned or replacement can-pruned

Question 19

Describe cordon training.

Answer 19

These vines typically have a trunk and one or more permanent horizontal arms of permanent wood, called “cordons”.

• usually spur-pruned
• cordon training takes longer to establish than head training due to the amount of permanent wood.

Question 20

Define winter pruning.

Answer 20

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

Question 21

What are the two main types of winter pruning?

Answer 21

1. spur pruning
2. replacement cane pruning

Question 22

Describe spur pruning.

Answer 22

• 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 23

Difference in ease of spur or replacement cane pruning?

Answer 23

- spur pruning is easier to carry out and can often be mechanized - replacement cane pruning is more complex and requires skill to pick suitable canes and train them

Question 24

Define and describe canes.

Answer 24

- canes are longer sections of one year-old wood, and can have anywhere 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 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

What are the benefits of bush vines?

Answer 27

- simple - inexpensive

Question 28

What is the climate where bush vines are popular, and why?

Answer 28

- 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 29

Three advantages of trellised training systems?

Answer 29

1. maximize light interception 2. increase air flow through the canopy, to reduce fungal disease 3. aids mechanization, by positioning the fruit in one area

Question 30

What is the disadvantage of trellising?

Answer 30

- expensive to establish, and requires maintenance

Question 31

Describe vertical shoot positioning (VSP).

Answer 31

- 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 vigor

Question 32

Describe Guyot training.

Answer 32

- when VSP is used on replacement cane pruned vines - single: one cane retained - double: two canes retained

Question 33

What are four split canopy systems?

Answer 33

- Geneva Double Curtain - Lyre - Scott-Henry - Smart-Dyson

Question 34

What are the three aims of summer pruning?

Answer 34

- enhancing grape ripening - reducing chances of fungal disease - making the vineyard easier to manage

Question 35

Describe debudding

Answer 35

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

Question 36

Why might growers often leave a high number of buds on the vine at winter pruning?

Answer 36

In case buds are damaged early in the growing season, e.g. by spring frost

Question 37

Describe shoot removal.

Answer 37

- 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-organized, open canopy

Question 38

Describe shoot positioning.

Answer 38

The shoots are tucked into the trellis wires in an organized manner to better organize the canopy and facilitate mechanization.

Question 39

Describe pinching.

Answer 39

- removes the tips at flowering - improve fruit set

Question 40

Describe shoot trimming.

Answer 40

- 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 41

Describe leaf stripping.

Answer 41

- removing leaves - reduce shading of fruit and hence enhance ripening - lower disease pressure through better air circulation and improved spray penetration

Question 42

Where might leaf stripping be avoided?

Answer 42

In warm and hot climates, excessive removal of leaves can expose the grapes to too much sunshine and heat and lead to sunburn.

Question 43

Describe crop thinning or green harvesting.

Answer 43

- removal of bunches of grapes - increase ripeness of those grapes left on the vine

Question 44

What is the timing of green harvesting?

Answer 44

- near veraison 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 the uniformity of ripening