7. Canopy Management

Question 1

what are the aims of canopy management?

Answer 1

• maximize effectiveness of light interception by vine canopy
• reduce shade within canopy
• ensure uniformity of microclimate for grapes so they ripen uniformly
• promote balance between vegetative and reproductive functions of vine
• arrange canopy for ease of mechanization/hand harvesting
• promote air circulation to prevent disease
• vine balance

Question 2

what is vine balance?

Answer 2

suitable balance between vine vigor and it’s yield. not over cropped and not under cropped. there is a link between yield of vine and quality of the fruit

Question 3

what is a vegetative cycle?

Answer 3

If a vine is under-cropped, there is not much fruit to ripen, therefore the vine focuses more on green growth versus fruit growth and ripening. This leads to a dense canopy and lower quality fruit. Reduced fruitfulness in the season leads to less fruit in the next season, and so on

Question 4

what is under-cropping?

Answer 4

when the yield of fruit is too low for the vigor of the vine. leads to vegetative cycle

Question 5

what is over-cropping?

Answer 5

When the yield is too high for the vigor of the vine. leads to weak vines for future yields.

Question 6

what determines vine vigor?

Answer 6

-growing environment: soil fertility, climate, natural vigor of vine, choice of rootstock, disease, wine style, vine age

Question 7

When are decisions made that influence the number of shoots and potential yields?

Answer 7

Winter pruning is the key time period

Question 8

explain how vine balance is relative

Answer 8

the yield at which a vine is balanced will depends on the natural resources of the vineyard, planting material, age of vine, presence of disease, and wine style

Question 9

what influences optimum vine density?

Answer 9

vigor of the vine (which is influenced by natural resources and planting materials), type of trellising , access needed between vines.

Question 10

what determines within-row spacing?

Answer 10

• vine vigor
• low vigor vines, VSP trained, can be planted closer together within the row to maximize vineyard land
• high vigor vines need more space, or risk overlapping canopies which increase shade and reduce ripeness and quality.

Question 11

Why are vines in dry regions, without irrigation, planted at low density?

Answer 11

so roots may spread out without competition from other vines in search for as much water as possible.

Question 12

why is between-row spacing important?

Answer 12

so one row does not shade the next

-vigorous vines that are high-trained and trellised need greater spacing between rows.

Question 13

row orientation depends on what?

Answer 13

climate and logistical factors, winds, sunlight exposure, slope (for mechanization)

Question 14

vine training and trellising depends on what three things?

Answer 14

• vigor of the vine
• site topography
• need for mechanization

Question 15

what effects vine vigor?

Answer 15

natural resources (temp, water, nutrients), planting material (grape clone, variety, rootstock), presence of disease (can lower yields), human interventions (limiting irrigation, low vigor rootstocks)

Question 16

why’s topography important regarding trellising?

Answer 16

many trellising systems cannot be used on steep slopes or windy sites.

Question 17

Why is considering mechanization important for trellising?

Answer 17

certain trellising systems are better suited for mechanization - VSP

Question 18

What is head training?

Answer 18

-relatively little permanent wood. Can be spur-pruned or replacement cane pruned

Question 19

what is cordon training?

Answer 19

these vines typically hav a trunk and one or more permanent horizontal arms of permanent wood (cordons). Usually spur-pruned. Takes longer to establish than head training.

Question 20

what are the two types of vine training?

Answer 20

head training and cordon training

Question 21

what are the two types of winter pruning?

Answer 21

Spur pruning and replacement cane pruning

Question 22

describe spur pruning

Answer 22

spurs are short sections of one year old wood (shoots from last growing season) that have been cut back to only 2-3 buds. Spurs can either be distributed along a cordon (cordon training) or around the top of the trunk (head training). Easier to carry out than replacement cane and can often be mechanized.

Question 23

describe replacement cane pruning

Answer 23

canes are longer sections of one year old wood and can have 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 required skilled labor to select suitable canes and train them.

Question 24

How does the number of buds left on a vine influence the balance of the vine?

Answer 24

the number of buds left depends on the vigor, more buds left for higher vigor vines. this influences the number and size of shoots in the growing season, and amount of fruit.

Question 25

Why would a vineyard be untrellised?

Answer 25

If unable to be mechanized due to steep slope, vineyards are in hot, sunny, and/or dry conditions which restrict vigor.
-simple, inexpensive, but cannot mechanize

Question 26

Vertical shoot positioning trellis systems are best suited for which vines?

Answer 26

low to moderate vigor

Question 27

Advantages of VSP trellising?

Answer 27

• simple

- can be used on both head trained, replacement cane-prune vines AND cordon-trained, spur-pruned vines

Question 28

Why would a grower use a more complex system than VSP for trellising vines?

Answer 28

If a vine is vigorous and ripens high yields of fruit, VSP would create dense canopy

Question 29

Why prune in summer?

Answer 29

• enhances grape ripening
• reducing chance of fungal disease
• makes vineyard easier to manage

Question 30

types of summer pruning?

Answer 30

disbudding
shoot removal
shoot positioning 
pinching
shoot trimming
leaf removal
crop thinning/green harvest

Question 31

describe disbudding

Answer 31

removal of buds to manage vine balance and yields, and to remove buds that are poorly positioned. disbudding late in the spring can be used to adjust the number of buds and bring vine into balance. also to remove buds of non-fruit bearing shoots.

Question 32

describe shoot removal

Answer 32

removal of lateral shoots that are infertile or poorly positioned. helps maintain open canopy

Question 33

describe shoot positioning

Answer 33

shoots tucked into trellis to organize canopy and help mechanization

Question 34

describe pinching

Answer 34

removes the shoot tips at flowering to improve fruit set

Question 35

describe shoot trimming

Answer 35

cutting shoots to limit growth and reduce canopy thickness. enhances fruit ripening by reducing competition for carbs.. lowers disease pressure by providing better air circulation

Question 36

describe leaf removal

Answer 36

removing leaves to reduce shading of fruit and enhance ripening, will also lower disease pressure through better air circulation and spray penetration.
*excess removal can increase chance of sunburn in hot climates

Question 37

What determines the number of buds left on the vine during pruning?

Answer 37

The vigor of the vine. More buds are left for more vigorous vines.