D1C07 Canopy Management Flashcards
Specific to canopy management: 1.2.3 Describe vineyard management options. 1.2.4 Explain how vineyard management options relate to the growing environment. 1.2.5 Explain how vineyard management options influence the production and ripening of grapes.
1
Q
What is vertical shoot positioning?
A
- most common type of trellising & most simple - best suited to vines with low-moderate vigour - called “Guyot” training when used on replacement cane pruned vines
2
Q
What will determine the most appropriate training + trellising system?
A
1) the vigour of the vine 2) the topography of the site 3) the need for mechanization
3
Q
What is the definition of yield?
A
A measure of amount of fruit being produced (can be measured per vine or over a set area)
4
Q
What is the definition of vine density? What determines optimum density?
A
- the number of vines that are planted per hectare in the vineyard - the optimum density is determined by vigour of the vine, type of trellising, and what access is needed between rows
5
Q
What is the definition of cordon training?
A
Vine training done on vines with 1+ horizontal arms or “cordons” (usually spur pruned)
6
Q
What are the aims of canopy management? (6)
A
1) maximize effectiveness of light interception by canopy 2) reduce shade within canopy 3) ensure microclimate for grapes is as uniform as possible 4) promote balance between vegetative + reproductive functions of vine 5) arrange vine canopy to ease in mechanization + manual labour 6) promote air circulation to reduce disease
7
Q
What are some examples of summer pruning?
A
- shoot removal, shoot positioning, pinching, shoot trimming, leaf removal and crop thinning and green harvesting
8
Q
What is the definition of head training?
A
Vine training done on vines with little permanent wood (can be either spur pruned or replacement cane pruned)
9
Q
What is replacement cane pruning?
A
- canes are sections of 1 year old wood that have 8-20 buds - typically laid down and need tying to a trellis - number of buds will depend on vigour
10
Q
What is spur pruning?
A
- spurs are short sections of 1 year old wood that have been cut back to 2-3 buds - easier to carry out/can be mechanized
11
Q
How were vines planted before and after the phylloxera epidemic?
A
before
- very close together
- random arrangement
- untrellised or trellised on individual stakes
- worked by hand
after
- straight lines toe enable cultivation using animals and subsequently tractors
12
Q
What is a trellis?
A
- a physical structure consisting of posts and wires that largely supports the grapevine framework (canes, shoots, folliage)
13
Q
When choosing a trellis system for a particular site which are the factors to consider?
A
-legislation
controlled in PDO regulations
-geographical features of the site
topography, wind exposure, rainfall, temperature, frost risk, soil fertility
-effectiveness of light interception
total canopy surface / ha
-cost and time of establishment
posts, wire, plants
-cost and time of maintenance
pruning, shoot positioning
-mechanisation potential
spraying, harvest, pruning
-popularity and attractiveness
14
Q
Why would vineyard managers use several trellis systems within one vineyard?
A
For instance, at the bottom of a slope, a higher trellis may be used to reduce frost risk
15
Q
Other names for untrellised vines?
A
Bush or free-standing vine
16
Q
Common locations for untrellised vines?
A
Still common in southern Europe
17
Q
How is un untrellised vine trained?
A
The vine trunk is trained short, no trellis
18
Q
How are untrellised vine pruned?
A
usually spur-pruned => bush vines or gobelets
can be cane-pruned by tying the canes together to form a “basket” => Santorini, Greece
19
Q
What are the advantages of untellised vines?
A
- least expensive way of growing a vine
- foliage can offer some bunch shade in warmer Mediterranean climate
- canopy management costs are relatively low
20
Q
What are the drawbacks of untellised vines?
A
- low yields due to the low planting density
- un-trellissed vines have been found to be more prone to disease due to less air circulation through canopy
- vineyards operations & harvest must be done by manually
21
Q
What are staked vines?
A
The vines are tied to a post (often wood) (driven into the ground next to the vine) for support.
22
Q
How are staked vines trained / pruned?
A
- In a crown (head) 20 - 30 cm above the ground and 2 - 4 canes are fixed to the stake
- spur-pruned, without a distinct crown, with the bearers radiating from the trunk in a circular shape
23
Q
What are the advantages of stake vines compared to bush vines?
A
- Can be trained higher than bush vines (simplifies vineyard operations)
- Canopy can be positioned to allow greater air circulation which reduces disease risk
24
Q
What are the drawbacks of stake vines?
A
Low density planting
Lower yield potential
Not suitable to high vigour site
25
Common locations for staked vines?
* Côte Rôtie, Southern France
* Spain
* Portugal
* Italy
* California
* South Africa
26
What is the advantage of the simple wire system over bush vines?
* forming a continuous row of foliage
27
What is the general advantage of the single wire system?
* relatively inexpensive to install and train
28
How are single wired vines trained / pruned?
* cordon-trained and spur pruned
* trunk usually divided 15 cm bellow the wire
* permanent horizontal cordon established
* head trained and cane pruned
* crown established below the wire
* up to 4 canes of 10 to 15 nodes fixed or wrapped along the wire
* 2 to 4 2-node replacement spurs
29
What is the main drawback of the single wire trellis system?
How is it solved?
* new shoots often hang down
* offering no protection to the fruit from sunburn
* solved by : designing multiple wire trellis systems which have a foliage wire to train the shoots upwards.
30
Common locations for two-wire vertical?
widely used troughout the world
widely adopted in California in mid 80ies =\> Califoria sprawl
31
Decribe two-wire vertical
* A single fruiting wire
* above this a single foliage wire 0,3 - 0,5 m
Can be suited to mechanical pruning and harvesting (depending on the canopy)
High vigour sites =\> lot of vegetative growth =\> more wires required
* to keep foliage of the ground
to aid canopy management operations
32
Common locations of vertical shoot positioning (VSP) trellis?
* France
* Germany
* cooler regions of Australia and New Zealand.
33
VSP is an example of?
non-divided canopy
34
Where was the VSP adopted?
In places where there is a high risk of fungal disease, in order to keep foliage off the ground, and to simplify spraying and trimming operations.
35
Describe VSP trellis?
* Consists of movable foliage wires which enable shoots to be trained into a narrow vertical canopy
36
How are VSP trellis pruned?
* cane-pruned (traditional Guyot)
* spur pruned on unilateral or bi-lateral cordons
37
Advantages of VSP and its pruning styles?
* all the fruit is in one zone and shoot tips in another
* simplifies mechanical operations (leaf removal, bunch zone spraying, summer trimming)
* vines can be harvested by machine
* can be converted to machine winter pruning
38
Main disadvantage of VSP?
* shoot density is normally high =\> prone to shade
* unsuited to high vigour varieties and high vigour sites
* complex trellis systems have been developed to cope with moderate to high vigour sites.
39
Give examples of vertical, divided trellis
For which sites are they suited?
* Scott-Henry
* Smart-Dyson
Suited for moderate potential sites
40
Where was the Scott-Henry system developed and trialed?
* developed in Oregon
* trialed in New Zealand and Australia
41
Describe the Scott-Henry system?
* vertical, divided system
* two fruiting wires at 1 m and 1,15 m
* shoots on higher wire are trained up between two movable foliage wires
* bottom foliage is positioned downwards with (generally) one foliage wire
* canopy about 2 m tall
* row spacing needs to be 2 m (to prevent shading)
* was developed for cane pruning
* widely adopted (new world) due to suitability for machine harvesting
* superseded by the Smart-Dyson system
42
Describe the Smart-Dyson system
* vertical, divided system
* aka Ballerina system
* cordon trained
* upward and downward pointing spurs
enables pruning by machine
43
What are the 3 principal advantages of the vertical divided systems over VSP?
* -canopy surface area is increased by about 60%
* gives the system a higher increased potential for photosynthesis and yields.
* -shoot density is almost halved
* canopy is less dense,
* fruit exposure is increased
* decrease in disease.
* -there is a de-vigorating effect as half of shoots are trained downwards.
44
What are the drawbacks of the vertical divided system?
- higher establishment costs
- greater level of expertise needed
45
Give examples of multi-wired, horizontal systems?
For what soils are they designed?
* Geveva double curtain
* U- or lyre system
* overhead pergola system
designed for high vigour soils
46
Describe the Geneva double curtain trellis (GDC)
* a horizontally divided trellis
* shoots trained downwards.
* The curtains are supported at the top and are free hanging.
* Curtains are at least 1 m apart, shoots at least 1 m in length
47
Why was the Geneva double curtain system designed?
* to improve yield & fruit composition in vigorous soil.
* The divided canopy led to a reduction in shading
* the downward pointing shoots meant that the basal buds & fruit were exposed to greater amount of sunlight.
* these factors were found to produce higher yields of better quality grapes
48
Explain pruning and harvesting in the Geneva double curtain system :
* spur pruned
* machine harvesting
49
What is the advantage of the downward shoot positioning of the GDC compared to VSP?
* downward shoot positioning causes desirable shoot devigoration
* GDC can convert dense, shaded canopies to low density ones, with more than 50 % yield increases obtained compared to VSP.
50
What are the main drawbacks of GDC?
* -expense of the materials
* the expertise required to train the vines.
51
Common location of GDC?
* AU
* California
* some part of Italy
52
Where was the U of Lyre system developed?
Fance
53
Where was the U of Lyre system adopted?
* California
* New Zealand
* cool regions of Australia, Chili and Uruguay
54
For what sites was the U of Lyre system developed?
* medium to high vigour sites
55
Describe the U of Lyre system?
* a horizontally divided trellis
* shoots trained upwards in two curtains.
* shape resembles a lyre
56
Explain pruning and harvesting with the U or Lyre system?
* can be readily machine pre-pruned
* a French machine harvester has specially been developed for this trellis system
57
What is the disadvantage of the U or Lyre trellis?
* -The centre of " U" need to be kept open to ensure good leaf and fruit exposure
* -shoots need to be positioned correctly & continually trimmed.
* -high cost of construction & maintenance
58
Common locations of Pergola / tendone trellis
* Chile
* Argentine
* Italy
* now more common for table grapes
59
Describe the pergola training system
* trained with trunks about 2 m high
* a system of wooden frames and cross wires supports the foliage and fruit
* framework is usualy high enough for tractors to pass underneath
60
Describe pruning in the U or Lyre system
either cane or spur pruned
61
Why is the pergola training system limited in use?
* High cost in construction
* high labour costs to maintain
*
62
Can a pergola system be used in high vigour sites? explain
Yes but
* canopy needs to be thinned to avoid
* shading problems
* increased risk of powdery mildew and botrytis
63
What trellis system is this?
U or Lyre trellis
64
What trellis system is this?
Geneva double curtain trellis or GDC
65
What trellis system is this?
The Scott Henry trellis system
66
What trellis system is this?
The Smart - Dyson trellis sytem
67
What trellis system is this?
The vertical shoot positioning trellis
68
What trellis system is this?
Two wire vertical trellis
69
What happens in un-pruned vines?
* they produce many short shoots further and further away from thee trunk
* these shoots provide irregular yields with many small bunches of high-acid, sugar-low berries
70
What are desirable objectives of pruning?
* To overcome the vine's natural tendencies, and force it to produce more suitable fruit
* To help organise the plant on the trellis
* Heavily pruned vines =\> fewer shoots =\> fewer leaves =\> reduced photosynthetic capacity =\> reduced vine vigour
* young vines =\> prune lightly, flower removal
* older vines =\> lightly pruned vines decrease in vigour by increasing fruit production
71
To achieve quality fruit, there must be :
* an appropriate balance between the level of crop and the leaf area on each shoot
* The number of flowers (later bunches - level of crop) on the vine shoot is determined in the previous year according to conditions at flower initiation
* The size of each shoot (leaf area) is determined at pruning =\> the more buds left on, the weaker their individual vigour
* more shoots have to share the limited amount of winter reserves and the capacity of the plant's root system
72
What is the effect of a heavy of too low crop on the quality of the fruit?
* a heavy crop on short shoots will lead to over-cropping
* high yields of low quality fruit
* weekens the vine the following year
* shoots that have a disproportional low crop will be over-vigourous
* cary on growing after véraison
* detriment of the quality of fruit
* large leaves and laterals
* canopy shading
73
What is the advantage of helping to orgnanise the plant on the trellis by pruning?
* plant can capture the maximum amount of light (important in cool climates)
* Leaf bunching is avoided
* reduces disease risk
* increase yield and quality
* Bunch ripening is better synchronised
* personel and machines can pass along the alleys without causing damage
* mechanical operations such as spraying and harvesting are more efficient ande effective
74
What is an ideal canopy?
Ideal canopy is homogenous along the row (15 shoots per metre) with an average leaf thickness of 1-1.5 leaves
75
How is vine vigour measured?
vine vigour is measured by weight of wood produced each year
76
What is a the "ideal" balance between fruit and leaf
* a shoot with moderate yiel
* a pencil thick shoot
* 12-15 nodes long with
* inter nodal length of 60mm.
* This should weight approx 30-40g in winter
77
What is the charge?
The number of buds to be left during winter pruning
78
How do you calculate the charge?
Count the number of ideal shoots produced in the previous growing season (small shoots may count as half, larger as 2 of 3)
Or
Remove the canes, weigh them then divide the weight by 30-40
79
How can the charge be affected by vine age?
* In vines less than 8 years old the charge is increased significantly
* in older vines it is increased by 5-15%
* to compensate for non breaking buds caused by winter injury
80
What is canapy management and what is the aim?
The organisation of the shoots, leaves and fruit of the grapevine to maximise the quality of the macroclimate of the leaves and fruit.
The aim is to improve quality and yield and to minimise disease risk.
81
Where is canopy management in particular important?
* In cool-climate regions and in the New World
* improvements in vine management
* planting of the vines on fertile soils
* =\> have exacerbated the problem of high vine vigour in fertile soils
82
What are the main aims of canopy management?
* to maximise the effectiveness of light interception
* to reduce canopy shading, particularly in the fruiting cluster / renewal zone
* to produce a uniform microclimate for fruit
* to achieve an appropriate distribution of the products of photosynthesis
* to arrange the locations of individual organs in restricted zones in space
83
How does canopy management maximise the effectiveness of light interception in vine canopies?
* By presenting a large canopy surface to the sun
* Encouraging early development of that canopy in the spring
* avoiding inter-row shading by having a maximum ratio of canopy height to alley width of 1:1
84
Wjy is the reduction of shading in the fruiting cluster / renawal zone important in canopy management?
In highly shaded leaves, the rate of respiration outstrips that of photosynthesis =\> the leaf consumes rather than produces energy.
Shade reduses the viability and succes of floral initiation in dormant buds =\> causing an imbalance between leaf area and fruit weight
Shaded flowers have lower rates of successful fertilisation and fruit set
Shaded berries keep cooler and so do not ripen as well as in cool climates
Shaded fruit has lower quality flavours and colours (some of the biochemical reactions that produce these are stimulated by sunlight
Shaded fruit and leaves have far greater risks of contracting fungal diseases, espacially powdery mildew and grey rot.
85
What are the benefits of uniform microclimate for fruit produced by canopy management?
* it leads to more synchronised ripening
* it also leads to a greater chance of picking at the optimum period
86
Why is the appropriate distributionof the products of photosynthesis achieved by canopy management so important?
* too much fruit and not enough leaves (overcropping) will generate poor quality fruit and reduce vine vigour
* conversely, too many leaves and not enough fruit will cause over-vigour growth, which will also produce poor quality fruit
87
Why is the arangement of the locations of individual organs (trunk, canes, shoots, leaves and fruit) achieved by canopy management so important?
* this facilitates mechanisation, particularly in pruning, pesticide application and harvesting
88
How is diagnosis done in canopy management?
* By measuring the quality of vine canopies when the grapes are ripening
* look out for :
* the leaf layer number (roughly, the thickness of the canopy)
* the percentage of exposed grape clusters
* leaf size and colour
* the presence of lateral shoots
* the percentage of shoot tips that are still actively growing
89
Who is Dr. Richard Smart?
a leading Australian viticulturist
90
how and what should be assessed before prescribing a canopy management technique
\* the potential fertility of the site by digging up a soil profile
* Water supply
* Soil fertility tests
* Performance of vines on similar soils
\* the vigour of the vine
91
How does Smart class the sites?
In 3 categories :
* high potential
* medium potential
* low potential
92
Describe a high potential site :
High vigour
deep soils usually 1m+
Fertile
Good water supply
High nutrient levels
93
What are the different views for planting density on high potential sites?
View 1 :
* Low density planting (\> 3000 vines / hectare)
* complex big vine trellis systems suggested (Ruakura twin two tier or Geneva Double Curtain)
View 2 :
* High density planting (e.g. Mount Etna, Adelaide Hills)
* to promote competition to reduce vigour
* if not dense enough =\> vigour not restricted sufficiently =\> large canopies that tangle and shade neighbouring vines
94
Describe a medium potential site :
Medium vigour
Soils 0.5 m-1 m deep
Adequate water supply
Average fertility
require average plant density 3000 - 5000 vines/ha
large VSP, Lyre, Scott-Henry recommended
95
Describe a low potential site
Low vigour
Soils less then 0.5m deep
Poor water availability in the season
Low fertility
High planting density 5000+ vines/ha
Ordinary VSP (single or double guyot or cordon)
* if there is sufficient water to meet the vine's needs
* In arid condition water availability will be limiting factor of vine vigour over soil fertility =\> thus very low density planting
96
Excessively low vigour is genarally due to :
How can it be solved?
* Drought stress (solved by irrigation)
* Low soil fertility (solved by increased fertilisation, drainage, addition of soil organic matter etc.
* Disease (solved by diagnosis and treatment)
97
How can excessive vigour be controlled
* selection of low vigour rootstock
* Increase water stress
* cover cropping (dekgewas)
* High density planting
* Removal of alternate vines increasing vine length and reducing shoot vigour and canopy density
* Root pruning
* Retro fitting a more complex trellis system
* Pinching (removal of shoot tips around flowering)
* Shoot positioning, trimming
* Leaf stripping
* Crop Thinning
* Green harvest
98
Explain root pruning
* a sub-soiling tine is passed through the vineyard at 30 - 50 cm from the vine row after harvest or pre-burst
* difficult to predict the response =\> pruning will stimulate root growth
99
Explain pinching :
* a strategy for excessively high vigour
* the selective removal of shoot tips around flowering
* usually done manually
* aims to make uniform shoot growth
* improve berry set
* In vigourous vines, this leads to an increase in the development in lateral shoots =\> have to be removed
100
What is the second most costly manual intervention in the vineyard
Winter pruning
101
What are the two common forms of pruning?
* replacement-cane (guyot)
* spur pruning (cordon)
102
Explain minimal or zero pruning :
* used for Thompson seedless table grapes (Australia)
* have reduced shoot growth and begin to self regulate
* the produce higher yields =\> suited to warmer climates
* a large amount of permanent woord develops over a number of years =\> has te removed now and then
103
Explain replacement cane system
* Popularised in the 1860's by Jules Guyot
* a cane pruned system with one or more spurs
* Cane buds grow into shoots that produce the yield in the following season
* Spur buds produce next years canes
* preventing the vine frow sprawling too far along the trellis
* Choice of single or double Guyot
* choice is usually down to vigour or laws
* Has to be carefully pruned
* straight trunk
* crown wel positioned in relation to the fruiting wire
* remove badly positioned shoots when they grow
* all flowers should be removed from the least vigourous young vines untill they establish themselves
104
What are the advantages of replacement-cane pruning?
* By limiting the carbohydrate reserves, the vine's vigour is kept under control
105
What is the disadvantage of replacement-cane pruning?
* winter pruning requires great skills
* can not be mechanised
106
When pruning replacement cane vines, how do you select the spur and cane?
* The spur should be selected first
* not too low under the crown
* nearer the roots than the cane
* pointing allong the row, not the alley
* the cane selected so that
* further from the roots than the spur
* should be able to be tied down (bowed)
* so it doesn't protrude into the alley
* so it does not invade the neighbouring vine's trellis space
* buds should be spread evenly along the trellis
107
What is "pendelbogen" and why is it used?
* Canes that are tied down in the shape of an arch
* to regulate shoot vigour along their length
* vines will grow more vigorously at their extrimities
* buds at the ends of canes furthest from the crown wil tend to break first and produce the most vigourous shoots
* the longer the cane, the greater the difference in vigour between shoots
* leading to uneven canopies
108
Explain spur pruning without a cordon
* head pruned: spurs that are distributed around the head
* bush vines or gobelet vines (if shoots are tied together at the top)
109
What are cordon / spur systems?
* Systems where the cane is left permanently attached to the fruiting wire so that it becomes a permanent cordon
* The canes coming of these cordons are then spur-pruned
* The shoots arising from these spurs can be trained either upwards or downwards
110
What is the most common cordon system?
Cordon the Royat
* a single or double horizontal cordon
* shoots then vertically trained
111
Give examples of cordon / spur pruned systems
* Cordon de Royat
* Sylvoz, Lenz - Moser systems
* "big vines" trellising systems (Geneva Double Curtain)
112
What are the advantages of cordon systems?
* Easier to prune
* can be pre-pruned mechanically
* retain a larger volume of permanent wood than replacement-cane systems
* Can help provide necessary carbohydrate systems
* =\> is important if bud breaks occurs while frost is still a risk
113
What are the disadvantages of cordon / spur pruning?
* larger carbohydrate reserves also enable the vines to be more vigorous than in replacement cane systems
* the loss of growing points along the cordon
* can be minimised by keeping cordons shorts, pruning according to charge
* If this fails =\> cordon will have to be replaced
* the lenghtening of growing points
114
What points should be considered when pruning concerning wood?
* wood retained should be in good state of health
* look out for spotting due to botrytis, powdery mildew, phomopsis, poorly ripened woord
* Canes with deformities shouldbe eliminate
115
What points should be considered when pruning buds?
* buds on canes formed in the previous year are the most fruitful
* if vine is pruned severely, old buds on the trunk will break
* the embyonic flowers within these will have degenerated
* will produce little fruit
116
What points should be considered when pruning concerning pruning cuts?
* if large cuts have to be made
* leave a stump that can be cut back the following winter
* unwanted canes must be cut back to old wood
* =\> surviving basal buds will turn into watershoots
117
What points should be considered when pruning concerning timing?
* earlier pruning ecourages earlier budburst
* increases risk of spring frost damage
* delayed pruning delays budburst
* avoids spring frost risk
* when left too late
* =\> when buds start breaking =\> takes longer to tie down the canes =\> many young shoots may be damaged
118
What do you do with pruning waste?
* can be collected and used as fuel or mulched in the alleys
* can increase the humus levels in the soil
* diseases (eutypa, blackrot) can overwinter on canes
* then burn pruning waste
119
What are the aims of summer training (Trimming off shoot extrimities)
* to control excessive shoot growth
* facilitate the passage of manpower and machinery
* reduce inter-row shading and winddamage
* Reduces canopy thickness to improve the micro-climate and spray penetration
* encourage the onset of maturity
* descouraging shoot growth
* stimulate berry development
* Aesthetics of the vineyard
120
What is the timing of summer training?
starts in July (northern hemisphere)
not too early, not too severely
121
What is shoot positioning?
Shoot removal
Bud rubbing
Tucking in
122
When should shoots be removed?
If they are:
Badly positioned (and would have to be removed at winter pruning anyway)
In contact or close to the ground
Rootstock shoots
Causing too much canopy shade (especially in the renewal zone)
123
When do you carry out shoot removal?
Summer trimming should take place after spring frosts but before flowering
124
What is the target shoots per metre in summer trimming
15 shoots per metre
125
How long does shoot removal take when done by hand?
17 - 50 hours / ha
126
What is bud rubbing?
Bud rubbing is the removal of the shoot before it has had chance to grow
127
What does the act of tucking in do?
* Aims to organise the canopy
* Helps to facilitate mechanisation
* important in upright canopies
* without it =\> shoots bunch together =\> flop to the ground =\> preventing the passage of machinery
* also important in downward-growing canopies
* shoots will resist growing downwards and form irregular canopies
* can be done by hand, using moveable wires
* can be done by machine
128
Explain the process of leaf stripping
* removal of leaves around the fruit zone
* done between véraison and harvest
* manually or by machine
* to improve the canopy microclimate
* improves fruit quality
* improves fruit health
* to improve spray penetration
* increase the speed of manual harvesting
* can take up to 70 hours / ha
129
What are the 5 major practices in canopy management?
1. Shoot thinning
2. Shoot positioning
3. Cluster thinning
4. Leaf removal
5. Shoot trimming
130
What are the aims of shoot thinning?
Shoot thinning, also called (trunk or cordon) suckering, is the removal of young excess shoot and helps to:
1. Redirect growth
2. Improve Aesthetics
It is done early in the season, when shoots are only 3 to 8cm long.
131
What is shoot positioning?
Shoot positioning, in VSP also known as tucking, is the practice of orienting the shoots in a vertical position parallel to the trunk to create a uniform distribution of foilage thus minimising the shading of the fruit.
Best done direct after bloom and before tendrils have become firmly attached to mimise breakage and to aid developing compound buds.
132
What is cluster thinning?
Cluster thinning is the removal of flower and/or grape clusters on the grape vine and is done to:
1. Control yield and avoid overcopping
2. Improve fruit quality
3. Modify vine balance
Cluster thinning is executed or pre-bloom or after fruit-set
133
What is leaf removal?
Leaf removal or leaf pulling is the removal of 1 to 4 leafs at the base of each shoot at the cool side of the canopy to expose clusters.
134
What is shoot trimming?
Shoot trimming, also called hedging, is the cutting of shoots that grow outside the allocated space in a trellis system in order to control shoot length.
A minimum of 12 to 15 leafs shall be kept per shoot in order to mature fruit and wood.
Depending on whether conditions several passes in a growing season can be required, but never after véraison, since this may cause delaid fruit ripening and reduced wood maturity.
