Winter Pruning

Question 1

5 goals of winter pruning

Answer 1

*Maintain a canopy shape suitable to cultural practices
* Regulate vegetative growth
* Retain enough fruitful nodes
*Regulate cluster number and their size
*Producing grapes of the desired quality

Question 2

First 3 principles of winter pruning

Answer 2

• Pruning reduces vine capacity
• Crop level reduces vine capacity
• Fruitfulness relates to shoot vigor

Question 3

Last 3 principles of winter pruning

Answer 3

• Shoot vigor is inversely correlated to shoot number and yield
• The grapevine self-regulates
• Shoot direction influences shoot vigor

Question 4

Any time we do winter pruning in a given vine and environment regardless of the pruning type, we are regulating 3 things:

Answer 4

• Number of cropping units (spurs, buds)
• Length of cropping unit
• Position of each cropping unit

Question 5

What is the vine capacity graph showing?

Answer 5

that every time we winter prune, we are reducing either yield potential and vine capacity.

Question 6

What is the difference between vine capacity and vine vigor?

Answer 6

Vine capacity = total leaf area

Vine vigor = speed of growth, cane weight, single cane growth

Question 7

Explain each point of the table:
Weak weak
Weak strong
Strong weak
strong strong

Answer 7

Weak weak: is the case of a small plant of 1 year old or a poor vine, very weak.

Weak strong: the case of mechanical pruning, because we are leaving on several nodes and so each shoot will grow a little.

Strong weak: the case of a young vine during the training phase showing just few shoots very vigorous, but the leaf area is still low.

Strong Strong: a bit rare, but a plant with several shoots and each of those shoots is very vigorous.

Question 8

What are the three modalities of winter pruning?

Answer 8

• Hand
• Mechanical (with or without hand follow up)
• “Minimal”

Question 9

What kind of pruning is this?

Answer 9

Guyot

Question 10

What kind of pruning is this?

Answer 10

Spur pruned cordon

Question 11

The main factor that has to drive us towards Guyot or spur pruning is…

Which do we do for high and low fruitfulness?

Answer 11

Basal bud fruitfulness

For high fruitfulness we can do spur pruning
For low fruitfulness we can do guyot

Question 12

Discuss this situation and the 2 advantages and 2 disadvantages

Answer 12

This is what the simonit guys do for spur pruned cordon

advantages:
- Vascular system is healthier
- smaller wounds and less chance of disease

Disadvantages:
- Because we are moving farther and farther away from the cordon we lose space for canopy
- If we bank on this situation and remove all other vegetation and we dont get the growth that we want we may be hosed for the season (risky)

Question 13

What is CV?

Answer 13

CV is the coefficient of variation

Question 14

What does the CV show us when we compare shoot position and leaf area with guyot and spur?

Answer 14

We can see that guyot has a much higher variation of leaf area per shoot according to the position of the shoot on the cane

Question 15

When spur pruning never ever exceed…

Answer 15

3 count nodes

Question 16

Mechanization with guyot could be problematic because…

Answer 16

You could shorten the cane that you would use for the next year depending on the length of the cane and the length between vines.

Question 17

If well conducted, short pruning should lead to…

Answer 17

More uniform shoot growth, hence ripening.

Question 18

With which training system did mechanical winter pruning begin?

Answer 18

GDC (Geneva double cordon)

Question 19

What is GDC?

Answer 19

It is a horizontally spilt canopy with spurs, the canopy is free as a type of sprawl canopy.

Question 20

_________ is a regulating factor for the vine.

Answer 20

Bud break rate

Question 21

What is the minimal goal that would make you happy with Mechanical winter pruning?

Answer 21

I want to save time, I dont have skilled workers, I also would be happy if I would get the same yield and the same quality. I cant pretend I can increase quality, but maybe I can get a similar yield and similar quality, saving time and money

Question 22

What are they doing?

Answer 22

performing the hand finishing to prune everything left under the cordon, where the machine doesn’t work.

Question 23

When you increase the nodes/vine we also get a…

Answer 23

Decrease in Bud Break

Question 24

With MMP - LF we get? (4)
Medium mechanical pruning - long finish

When should we absolutely not do this?

Answer 24

• higher nodes/vine
• lower bud break(shoot/node)
• a decrease in overall quality
• an increased yield.

To do this with a high basal bud fruitfulness would be worse…

Question 25

What is minimal pruning?

Answer 25

Not winter pruning, only summer pruning

Question 26

Self regulation prevents…

Answer 26

overcropping and vine exhaustion

Question 27

What are the three advantages of minimal pruning?

Answer 27

1. In spring there is a much bigger canopy so there is higher light interception, and earlier photosynthetic activity
2. Lots of shoots with low vigor, they reach around half meter of length and then they stop, so it means that still at flowering there’s no competition with the inflorescences, ideal condition for ripening.
3. Technique allows to get much more clusters, but definitely smaller, loser and with small berries

Question 28

4 considerations with minimal pruning

Answer 28

1. Increased Yield
2. Yield tends to vary from year to year (barely controlled)
3. Quality can be acceptable
4. Best adapted to Med climates. Too cool and we can have delayed ripening and botrytis

Question 29

What is “fence” pruning or semi-minimal pruning?

Answer 29

A modified version of minimal pruning that is best adapted to wet conditions

Question 30

What are the findings with fence pruning? (5)

Answer 30

1. Yield was slightly higher
2. Higher brix
3. Higher color
4. Less botrytis
5. Mechanical harvesting works better

Question 31

Considerations with wood diseases with pruning spur vs guyot (3)

Answer 31

1. It is not really about the size of the cut, but how many cuts we make, so spur can be worse for wood diseases.
2. It also depends on the weather and if its cold and wet after we cut the scarring will be slowed
3. We should perform winter pruning later as also to avoid frost damage