2.1 Dormancy

Question 1

When is Dormancy in the Northern Hemisphere?

Answer 1

November–March

Question 2

When is Dormancy in the Southern Hemisphere?

Answer 2

May–September

Question 3

Why does dormancy occur?

Answer 3

Average air temperatures below 10°C (50°F) are too cold for the vine to grow and therefore in winter the vine is dormant.

Question 4

What temperatures does the vine need during the dormancy stage? What adverse conditions can occur during dormancy?

Answer 4

• Temperatures below 10°C (50°)
• Adverse conditions:
• – Extremely cold temperatures
• – Unusually mild temperatures

Question 5

What does dormancy start with? End with?

Answer 5

Winter dormancy typically starts with leaf fall in the autumn and ends with budburst in the spring.

Question 6

How does the vine support itself during dormancy?

Answer 6

Until it has grown new leaves, the vine supports its growth by using stores of carbohydrates, mostly starch, accumulated during the previous growing season in the roots, trunk and branches.

Question 7

At what temperatures can vines be severely damaged? Killed?

In what regions is this a problem?

Answer 7

• Temperatures below −15°C (5°F).
• Temperatures below −25°C (−13°F) will kill most V. vinifera.
• Problematic during Winter in Canada, New York State and China

Question 8

What type of vineyard activities are done during dormancy?

Answer 8

Winter pruning is carried out during this dormant period

Question 9

What marks the end of winter dormancy?

Answer 9

Budburst