2.3 Shoot & Leaf Growth

Question 1

When is Shoot and Leaf Growth in the Northern Hemisphere?

Answer 1

March–July

Question 2

When is Shoot and Leaf Growth in the Southern Hemisphere?

Answer 2

September–January

Question 3

What is Shoot and Leaf Growth?

Answer 3

When the shoots continue to grow, and leaves and inflorescences (a cluster of flowers on a stem) mature.

Question 4

When does the fastest rate of shoot and leaf growth occur?

Answer 4

The fastest rate of growth generally occurs between budburst and flowering

Question 5

What nutrients initially supports shoot growth?

Answer 5

• Initially: Carbohydrates stored in the roots, trunk and branches of the vine support the initial shoot growth.

Question 6

What eventually supports shoot growth?

Answer 6

• As leaves develop and mature, they provide energy for further growth via photosynthesis, and therefore need adequate warmth and sunlight for this to take place.

Question 7

What 4 factors might contribute to low carbohydrate levels?

Answer 7

In the previous season:

• Excessive leaf removal
• Water stress
• Mildew infections
• High crop loads

Question 8

What main problem can occur during shoot and leaf growth? Why is this problematic?

Answer 8

Water stress

• Can limit photosynthesis and shoot growth
• Can limit nutrient uptake through the roots

Question 9

What does stunted shoot growth lead to?

Answer 9

• Small, weak shoots
• A reduction in leaf number or smaller leaves
• Inflorescences that do not flower properly
• Grape bunches that do not ripen fully
• Poor quality
• Lower yields

Question 10

What does the vine needs during this stage? What are some adverse conditions?

Answer 10

What the vine needs during this stage:

• Stored Carbohydrates
• Warmth, sunlight, nutrients and water

Adverse conditions:

• Low carbohydrate levels (caused by conditions in the previous growing season)
• Water stress