D1: Canopy management 11

Question 1

The key aims to canopy management:

Answer 1

1) maximise the effectiveness of light interception by the vine canopy

2) reduce the shade within the canopy
3) ensure that the microclimate for the grapes is as uniform as possible so that the grapes ripen evenly

4) Promote balance between the vegative and reproductive functions of the vine
5) arrange the vine canopy to ease mechanisation and or manual labour
6) promote air circulation through the canopy to reduce incidence of disease

Question 2

Vine organs (buds leaves and fruit) develop in different ways when they are in shade or exposed to sunlight:

Answer 2

1) in the wild a vine needs it fruit to be exposed to the birds for propagation of its seeds
2) in forest conditions, it will grow untill it finds sunlight
3) viticulture: a canopy well exposed to sunlight promotes a greater number of inflorescences developing inside the latent bud (called for fruitfulness)
4) maximise the leaf surface area so increased photosynthesis and leads to larger yields

Question 3

Good canopy management can also reduce the chance of fungal diseases:

Answer 3

1) poor air circulation= slower drying out of canopy= increased chance on fungal diseases
2) dense canopies are problematic when spraying fungicides, as it is more difficult to ensure the spray reaches all the areas of the canopy

Question 4

The influence of canopy management in determining the exposure of the leaves and grapes to sunlight also has a possitive effect on grape quality:

Answer 4

1) increased sugar levels in grapes through greater overall photosynthesis in the vine
2) increased tannin levels and greater polymerisation of those tannins, which leads to less bitterness
3) enhanced anthocyanin (colour) development in black grapes
4) decreased malic acid: warmer grape temp, leads to more malic acid being broken down in cellular respiration, otherwise acidity levels in the wine could be unpleasantly high (tartaric acids remain)
5) increased levels of some aroma precurcors and aroma compounds (such as terpenes, who give many of the fruity and floral aromas such as the grapey aromas found in muscat)
6) decreased methoxypyrazines, which give herbaceous character in CS

Question 5

All these processes taken together can result in fully ripened grapes with high quality potential, in relation to black varietes:

Answer 5

1) Without full ripeness, grapes would have unpleasantly high levels of acidity, harsh tannins and unripe frui character, all of which would reduce wine quality
2) fully ripened grapes: produces wine with a good depth of colour, ripe fruit aromas, balancing acidity and ripe tannins

Question 6

Suitable balance between the vines vigour and crop load is essential for successful grape ripening and sustained production over future growing seasons:

Answer 6

1) until véraison, the vines sugars and nutrients are mainly allocated to shoot and root growth and storage
2) after veraison, sugar and other compounds needed for growth are mainly allocated to the fruit and shoot growth is depressed

3) Because shoot growth is reduced, the canopy is less likely to become dense and shady and light exposure in the canopy is improved, leading to high quality fruit
* also results in enhanced budfruitfulness the next year

** balanced cycle

Question 7

By comparison if the yield of fruit is too low for the vigour of the vine:

Answer 7

1) under cropping: shoot growth continues through the vinecycle because there is not much fruit to ripen
2) the growing shoots are competing for sugar and other nutrients with the grapes and can lead to negatively grape formation and ripening
3) this also leads to a denser canopy, so less sunlight is reacing the grapes, hence lower grapequality
4) also can lead to lower yields next year due the to reduced bud fruitfulness
5) low yields in the next season may lead to undercroppin for the vines vigour that season

*** vegative cycle

Question 8

If the yield of fruit is too high compared to the vigour of the vine (over cropping:

Answer 8

1) the vine may gain sugars from the carbohydraes stored in the trunks, cordons and roots
2) the vines generally needs these carbohydrates sources in the next winter and spring and too high crop load therefore weakens the vine in future years

Question 9

The ideal amount on fruit on the vine will depend on:

Answer 9

1) its growing environment
2) warm temp, enough water and fertile soils vines can grow vigorously, producing a lot of shoots and leaves
* many leaves: greater photo: enough sugar and other compounds needed for growth

** these vines can succesfully ripen a large crop load

Question 10

The correct balance of the vine will also depend on the vine itself:

Answer 10

1) some varieties or clones are more vigorous tthan others: CS more than Merlot
2) some rootstocks more vigour than others

Question 11

diseases also influence vigour, viruses can lower vine vigour

Answer 11

Similar, very old vines will be less vigorous than vines that are 10-40y old

Question 12

Winter pruning is the key time when decisions are made that will influence number of shootsand crop load in the coming growing season.

Answer 12

Summer pruning techniques may be applied during the growing season to amend the vine balance and enhance ripeness

Question 13

Yield is a measure of the amount of fruit prduced

Answer 13

1) this can be measured per vine (eg kg per vine) or over a set area (eg kg per ha or tons per acre)
2) it is likely to produce fruit of lesser quality on an unbalanced vine

3) the yield at which the vine is balanced will depend on:
* Natural resources of the vineyard
* planting materials
* and the winestyle

4) even yield per vine is low the yields per ha can be high due the density of vines planted to gain as much yield as possible from the vineyard area
* in EU legislation may specify max yields per ha

Question 14

Canopy management encompasses a range of techniques that include:

Answer 14

1) site assessment to determine the ideal grape variety, rootstock vigour, planting density and row orientation

2) vine training
3) winter pruning
4) vine trellising
5) overall plant vigour management (nitrogen fertilisation, irrigation, cover cropping)

6) summer pruning:
* shoot removal
* shoot positioning
* Pinching
* shoot trimming
* leaf removal
* crop thinning/ green harvesting

• • canopy management should be a key consideration when establishing a vineyard
• choices regarding vine density will affect the vine training and trellising and therefore need to be decided before vine planting

Question 15

Vine density is the number of vines planted per ha of vineyard.

Answer 15

vine densities range from as low as a few hundered vines per ha to over 10000 per ha

Question 16

vine density will influence within row spacing and therefore needs to be considered during vineyard establishment.

Answer 16

1) the optimum vine density is influenced by the vigour of the vine (which in turn is inflenced by natural resources and planting materials)
2) the type of trellising system is used and what access is needed between the vines

• vines that are low in vigour and VSP trained, can be planted close to eachother
• vines with a greater within row space are not taking fully advantage of the vineyard space and this can be non effective in Burgundy where the land is very expensive to buy and and therefore a high density is maximising the space of the expensive lands

Question 17

Vines that are too high in vigour will need a greater within row spaceing to grow and be in balance.

Answer 17

Planting these vines too close together will lead to overlapping of the canopies, reducing ripeness and quality

** vines grown in dry regions without irrigation may also be planted at low density, despite not being large in size, so that the roots can spread out (without competition for other vines) in search for as much water as possible

Question 18

Between row spaces also need to be considered:

Answer 18

1) vines rows should be planted far enough apart so that one row does not shade the other
2) therefore vigorous vines that are high trained and trellised need greater spacing between the rows
3) the width of any machinery that might be used also needs to be considered when planning between row spacing

** overall, low density, widely spaced trellised vineyards are usually cheaper to establish and maintain than high density, thightly spaced vineyards requiring less planting materials and permitting easier mechanisation

Question 19

Row orientation will depend on both climatic and logistical factors:

Answer 19

1) a north south orientation provide the most even sunlight exposure through the canopy
2) the warm afternoon sun, requires the bunches of grapes at the west side to have a thicker canopy to shade

3) prevailing winds may also be a factor in decisions on row orientation
* choose to orient the rows at a 90° angle to the direction of the wind to provide most protection

4) from a logistical point: orienting rows parallel to the longest side of the vineyard is often the most efficient option
* vineyards on a slope at an angle of greater than 10% need to be planted up and down the slope rather than across or machinery may slip (unless the vineyard is terraced)

Question 20

The optimum method of vine training need to be decided at vineyard establishment: the most appropriate training and trellising method will depend on:

Answer 20

1) The vigour of the vine:
2) The topography: many trellising systems cannot be used on steep slopes or windy sites

3) the need for mechanisation: certain training and trellising systems are more suited to mechanisation than others

Question 21

Vine training:

Answer 21

Vine training: shape of the permanent wood:

1) head training
2) cordon training

• both can either be short trained: to benefit from the heat retained by the soil or provide greater protection from winds
• or high trained: to protect agains frost or make manual interventions such as harvesting easier

Question 22

Head training:

Answer 22

These vines have relatively little permanent wood

• the permanent wood usually consist of the trunk sometomes with a few short stubs growing from the top of the trunk
• • they can be spur pruned or replacement cane pruned

Question 23

Cordon training:

Answer 23

1) these vines typically have a trunck and one or more permanent horizontal arms of permanent wood
2) usually spor pruned: cordon training takes longer to establish than heat training due the amount of permanent wood

Question 24

Vine pruning:

Answer 24

It is the removal of unwanted parts of the vine it can take place in winter and summer and it determines the number and location of buds that will form shoots in the coming growing season

Question 25

Spur pruning:

Answer 25

Spurs are short sections of one year old wood (the shoots from the last growing season that have lignified (verhard) that hae been cut back to only two or three buds
** spurs can either be distribute along a cordon or arojnd the top of the trunk or around the top of the trunk (head training) spur pruning is easier to carry out than replacement cane pruning and can often be mechanised

Question 26

Replacement cane pruning:

Answer 26

Canes are longer sections of one year old wood and can have anything in between 8-20 buds they are typically laid down horizontally and need tying to a trellis for support and positioning

** more complex than spur pruning and requires a skilled labour force to pick suitable canes and train them

the number of buds left on the vine will depend on the vigour of the vine, with more buds left on for more vigorous vines

** this in turn influence the number and size of shoots in the growing season and the amount of fruit, thus greatly influencing the balance of the vine