Vineyard Cycle

Question 1

Bud Burst - which months does bud burst occur?

Answer 1

Northern hemisphere - March - April
Southern Hemisphere - sept - Oct

Question 2

Bud burst - key points

Answer 2

Occurs in spring and is the start of the growing season
Buds swell and burst into new shoots

Question 3

Bud Burst - what temperature does it need to be for Bud Burst to happen?

Answer 3

Usually when the mean temp is above 10.C
It also depends on grape variety. Pinot noir and Sauvignon blanc early budding varieties and doesn’t mind cooler temps whereas Cabernet Sauvignon is a late budding variety and need warmer temps

Question 4

Bud Burst - what negative factors affect bud burst?

Answer 4

Frost can kill buds at this stage and reduce yields especially in early budding varieties

Question 5

Early Shoot and Leaf Growth - what time of year does this cycle occur?

Answer 5

Northern Hemisphere - March - May
Southern Hemisphere - Sept - Nov

Question 6

Early Shoot and Leaf Growth - Key Factors

Answer 6

Shoots grow rapidly until the vine flowers

Question 7

Early Shoot and Leaf growth - what fuels this stage?

Answer 7

Initially it is fuelled by carbs retained in roots from winter dormancy. Once leaves start to form then this is fuelled by photosynthesis

Question 8

Early Shoot and Leaf Growth - what does the vine need in order for shoots and leaves to grow?

Answer 8

Good supply of water and sufficient nutrients as well as sunlight which can be achieved through tying shoots to trellis wire to keep the canopy open if practised

Question 9

Flowering and Fruit Set - when does this occur?

Answer 9

Northern Hemisphere - May - June
Southern Hemisphere - Nov - Dec

Question 10

Flowering and Fruit Set - what does the inflorescence need to start flowering?

Answer 10

It needs sunlight, warm temps and no rain otherwise pollination can be affected and fruit set affected

Question 11

Flowering and Fruit Set - When does Fruit Set Occur?

Answer 11

When flowers start to develop in to grapes

Question 12

Flowering and Fruit Set - what is coulure?

Answer 12

Not every flower turns into a grape unpollinated flowers drop off the vine if more flowers than normal do not turn to grapes this is coulure.

Question 13

Flowering and Fruit Set - what is Millerandage?

Answer 13

This is when grapes can form without seeds and remain small. This reduces yields

Question 14

Flowering and Fruit Set - What causes Millerandage?

Answer 14

Cold, cloudy or rain during pollination

Question 15

Veraison - when does this occur?

Answer 15

Northern Hemisphere - July-Sept
Southern Hemisphere - Jan - March

Question 16

Veraison - what colour are the grapes at this stage

Answer 16

Both black and white grapes are green at this stage and feel hard

Question 17

Veraison - How long does Veraison last for?

Answer 17

6-8 weeks after fruit set and this is where grapes start to grow

Question 18

Veraison - What happens during Veraison?

Answer 18

Grapes start to ripen
The skins start to change colour from black to red/purple and white to translucent/gold

Question 19

Veraison - What 5 things happen between Veraison and Harvest?

Answer 19

Grapes swell and fill with water
Acidity levels drop
Grape sugar levels rise
Colour pigments and flavour compounds accumulate
Tannins develop

Question 20

Veraison - What conditions does the vine need in order for Veraison to be successful?

Answer 20

Warm sunny weather as well as mild water stress to concentrate energy to the grapes to increase flavour

Question 21

Veraison - what will summer pruning do to help the vine through this period?

Answer 21

Summer pruning will remove excess foliage to make sure the canopy remains open

Question 22

Veraison - what can the grower do to to control yields?

Answer 22

He can green harvest to control yields which will also concentrate flavours

Question 23

Harvest - when does this occur?

Answer 23

Northern hemisphere - Sept-Oct
Southern Hemisphere - March-April

Question 24

Harvest - What conditions are ideal for the harvest period and why are these conditions important?

Answer 24

Dry - Excess rainfall can cause grapes to swell and dilute flavours
Damp conditions can also promote rot

Question 25

Harvest - if practised when should spraying end?

Answer 25

It should end a long time before harvest so that chemicals are no longer in the grapes

Question 26

Winter Dormancy - when does this occur?

Answer 26

Northern Hemisphere - Dec-March
Southern Hemisphere - June - Sept

Question 27

Winter Dormancy - what happens to shoots during winter?

Answer 27

Shoots turn to wood and they are now called cane

Question 28

Winter Dormancy - what other things occur at the start of this period?

Answer 28

Leaves fall and vines start store reserves as carbohydrates in the roots

Question 29

Winter Dormancy - what can kill buds and vines in winter?

Answer 29

Extreme cold around -20.c can kill the vine and buds

Question 30

Winter Dormancy - what can be done the combat extreme cold?

Answer 30

Earth may be piled up around the vine to provide some protection

Question 31

Winter dormancy - what are the growers duties during winter?

Answer 31

Winter pruning - this is where the grower can control yields by deciding how many buds there will be next season