D7: Canopy Management Flashcards
1
Q
What are the six main aims of canopy management?
A
- maximise effectiveness of light interception
- reduce shape
- uniform microclimate for grapes (ensuring equal grape ripening)
- balance vegetative and reproductive functions of the vine
- ease mechanisation/manual labour
- promote air circulation so reducing risk of disease
2
Q
Describe an imbalanced vegetative cycle (where there is an imbalance between shoot and fruit growth)
A
- fruit weight per shoot is reduced
- Shoot growth is stimulated due to less fruit growth
- Canopy density increases due to more leaf area
- Shade depresses bud-break, bunch initiation, fruit set, berry growth
= vegetative cycle
3
Q
Describe a balanced cycle (where there is balance between shoot and fruit growth)
A
- fruit weight per shoot is increased
- shoot growth is depressed due to more fruit growth
- canopy density decreases due to less leaf area
- shade stimulates budbreak, bunch initiation, fruit set and berry growth
= balanced cycle
4
Q
What is the link between canopy management and yield?
A
- vine canopy which is well exposed to sunlight is good for yields in the NEXT growing season as get more inflorescences developing inside latent buds
- maximises leaf area exposed to sunlight
- increases photosynthetic capacity
- can ripen larger yields
- reduces fungal disease by promoting air circulation
- helpful in ensuring fungicides reach all parts of vine when sprayed
5
Q
What is the link between canopy management and quality?
A
- greater overall photosynthesis so increased sugar levels
- increased tannins, greater polymerisation, less bitterness
- enhanced anthocyanin development in black grapes
- decreased malic acid (broken down more in warm conditions)
- increased level of some aroma precursors (e.g. terpenes)
- decreased methoxypyrazines
EXAMPLE
in a black grape which is NOT fully ripe: high acid, harsh tannins, unripe fruit characteristics
6
Q
What is the impact of hot temps and intense sun?
A
- can cause sunburn
- has a negative impact on quality and yields
7
Q
What is the link between canopy management and vine balance?
A
- optimal crop load allows grower to grow max yield of high quality grapes
8
Q
What is overcropping?
A
- yield of fruit too high compared to vigour of vine
- vine takes sugars from carbs and stores them in trunk/cordons/roots
- weakens vine as doesn’t then have these essential stores for winter and spring
9
Q
What is the importance of achieving good balance in the vine?
A
- higher/more vine leaves = more ability to photosynthesise and produce sugars and compounds needed for growth so can ripen a larger crop load
- limited resources = won’t grow; shoots and leaves low in vigour; cannot ripen full crop load
- right grape and clone = e.g. cab is more vigorous than merlot
- right rootstock
- disease = viruses can lower vine vigour
- age = older vines are less vigorous
- pruning = timing of summer and winter pruning have significant impact on balance
10
Q
What is ‘yield’?
A
- measure amount of fruit produced (either measure per vine or over a set area)
- yield at which vine is balanced depends on natural resources in vineyard, planting material (including age) and style of wine being produced
- higher yield within set area, more wine can be made and sold
- EU legislation specifies max yields in some areas
- even if yield of individual vine is low, vines may be planted at higher density to ensure as high a yield as possible
11
Q
What are six possible canopy management techniques?
A
- Site assessment (determines grape variety, rootstock vigour, planting density, row orientation etc)
- vine training
- winter pruning
- vine trellising
- overall plant vigour management (fertilisation, cover cropping, irrigation etc)
- summer pruning
- all key considerations pre-establishment
- weather impact in one year can be huge (flowering, fruit set, ripening)
12
Q
What are the seven components of summer pruning?
A
- disbudding/debudding
- shoot removal
- shoot positioning
- pinching
- shoot trimming
- leaf removal
- crop thinning/green harvesting
13
Q
What do you need to consider when thinking about density of planting?
A
- influences within-row and between-row spacing
- influenced by vigour of vines, trellising needed and access between vines
- low vigour vines and VSP trained vines can be planted close together
- want to make sure that you maximise land (esp if expensive) so don’t want to leave too much space
- high vigour vines need space in order to be balanced, ensure canopy isn’t overlapping (reducing light exposure) so grapes don’t reach ripeness etc
- need to consider irrigation (as if in dry area needs to make sure roots have space to spread)
- row spacing is important - should be far enough apart so no shading, allows machinery to get through, impact on trellising
14
Q
What is the cheapest and easiest form of vine density?
A
- low density
- wide spaced
- easier to maintain but need to consider all points relating to vine density
15
Q
What do you need to consider when thinking about row orientation?
A
- climate and logistical factors
- N/S orientation provides most exposure although issue of grapes on west-side of canopy could get too much exposure in afternoon sun
- need to consider wine as well - choose 90 degree angle to direction of wind to provide most protection
- on slopes, need to plant up and down rather than across so machinery doesn’t slip (unless terraced)
