Shoot Trimming

Question 1

What is shoot trimming and how is it performed?

Answer 1

Shoot trimming is when we cut the top of the shoots above the top setting wire. This is typically done mechanically.

Question 2

What is the reaction of the plant to shoot trimming

Answer 2

The production of lateral shoots. When we remove the apices we remove the apical dominance

Question 3

The need of repeated trimming is a sign of the vines

Answer 3

being out of balance

Question 4

How many times should we do a trimming in a season?

Answer 4

We can definitely do one, maybe two, but more than that is not good

Question 5

What are the two major things that are changed when we do shoot trimming?

Answer 5

1. Total leaf area
2. The canopy age (we are removing the youngest leaves)

Question 6

What are the other four things that are affected by shoot trimming?

Answer 6

1. Total light interception
2. Leaf and cluster microclimate
3. Leaf-to-fruit ratio
4. Primary-to-lateral leaf ratio

Question 7

When is the best time to perform shoot trimming and why?

Answer 7

The best time is pre-bloom as we are only removing the young leaves and not the mature ones that are the most photosynthetically efficient. However the actual best time is fruit-set

Question 8

What is the main purpose of pergola in trentino

Answer 8

Light interception

Question 9

Why would we not actually want to trim pre-bloom and instead trim at fruitset?

Answer 9

Because at pre-bloom the shoots are not long enough to be trimmed and even if we could it would negatively affect fruit-set

Question 10

How are we negatively affecting fruit set?

Answer 10

Because we would be removing the strongest carbon sink at the time and most of the energy would go to the inflorescences causing an increase in fruit set and at this time in the year, would lead to the cluster becoming too compact

Question 11

What are the three reasons why if we trim at fruit set we get leaves of the laterals that are best for ripening?

Answer 11

• they are younger;
• they are photosynthetically more efficient, because they are located on top of the canopy with the
  right inclination, so they intercept more light;
• they are carried on laterals which are vegetative shoots, so there isn’t any competition with other
  clusters, all of the energy from photosynthesis is moved exclusively to the primary clusters.

Question 12

However, considering that due to climate change the goal is not just reaching ripening, but delaying ripening what can we do?

Answer 12

We can perform shoot trimming at veraison, we won’t get any lateral regrowth, and so we can delay ripening

Question 13

we need at least _________ to reach expected quality

Answer 13

1 m2 of leaf area per kg of fruit

Question 14

The typical compensation effect of photosynthesis because the plant is able to compensates for the laterals removed by

Answer 14

increasing the photosynthesis rate of the main leaves

Question 15

If we trim at fruit set, what month does that fall on? What happens after that?

Answer 15

Around mid June. 45 days after we have veraison and 45 days is the same amount of time for a leaf to be at max function

Question 16

How do laterals affect the vine?

Answer 16

Because laterals don’t usually bear fruit, they benefit the cluster

Question 17

What happens if we were to only leave 6 leaves

Answer 17

Only leaving 6 leaves there is a feedback inhibition for photosynthesis, there is no more compensation because they are at their capacity.

Question 18

When and how are determined by the grower?

Answer 18

False they are determined by the vine

Question 19

The problem of using a delayed shoot trimming as a tool to delay ripening is…

Answer 19

A technical problem, we would need to wait until veraison and at this point we would be cutting the good leaves

Question 20

As we know in sprawl canopy, we should…

Answer 20

be able to maintain an open mostly up ride canopy

Question 21

Two advantages of sprawl canopy?

Answer 21

1. It is less expensive
2. It can be greatly mechanized

Question 22

How can we do a sprawl canopy with varietals that dont like to stay upright? What is a potential consequence of this?

Answer 22

We can do a short trimming on each side and on top to promote lateral shoots. The consequence can be that with such strong laterals, in vines like pinot noir, the laterals can bear clusters

Question 23

The more severe the trimming, the

Answer 23

Larger the lateral shoot is