Grape Growing

Question 1

What is Green Harvesting?

Answer 1

Green Harvesting is the process of removing grape bunches from a vine, with the aim of balancing leaf and/or fruit weight for a crop that can achieve better ripeness.

Question 2

Why is Green Harvesting Important?

Answer 2

The leaves carry out the photosynthesis process that produces the sugars, allowing the grapes to ripen. So if there are too many grapes and not enough leaves, the vine will struggle to ripen the berries. In summary, the remaining grapes will become more concentrated with fewer grapes.

Question 3

What is Chlorphyll?

Answer 3

Chlorophyll is the natural compound in green plants that gives them their vibrant color and helps plants absorb energy. This is when photosynthesis begins. After absorbing light the energy is transferred into two kinds of energy-storing molecules. Through photosynthesis, the plant uses the stored energy to convert carbon dioxide (absorbed from the air) & water into glucose, a type of sugar.

Question 4

What is Veraison?

Answer 4

The onset of grape ripening; When the grapes turn from green to red and naturally sweeten.

Or in the Case of white grapes, the grapes begin to become more translucent.

Veraison is very much the tipping point in a grape vines’ annual life cycle. It’s when the vine alters it’s focus from energy creation, to energy consumption (where it focuses on raising sugar levels & lowering acids)

Question 5

When does Veraison Occur?

Answer 5

Northern Hemisphere: Late July

Southern Hemisphere: Late January

Question 6

What is Must Weight?

Answer 6

A measure of the amount of sugar in grape juice, and hence indicated the amount of alcohol that could be produced if all fermented.

Question 7

Refractometer Scales

Answer 7

1 degree brix = 1 gram of sucrose

Question 8

Brix

Answer 8

A measure of the solids in a liquid. Commonly used to measure the dissolved sugar content of an aqueous solution (essentially simple syrup in a grape).

Question 9

How long does the ripening process take?

Answer 9

Following the onset of veraison, the ripening process takes anywhere from 30-70 days for the grape to become ready to make wine.

Question 10

How many leaves does a shoot need?

Answer 10

Each grape shoot needs14-16 well-exposed leaves to properly ripen a grape cluster.

If to many shoots are crowded together the leaves do not get enough light for effective photosynthesis.

Shaded leaves only function at 6% of their capacity.

Question 11

Millerandage

Answer 11

Extreme uneven ripening. This can lead to wines that smell sweet, but that taste unbalanced, unripe, or green.

Common in: Pinot Noir, Sangiovese, Gewurtztraminer, Zinfandel.

Question 12

At what temperature do dormant buds begin to grow producing shoots?

Answer 12

In the spring, when the daily temperatures are about 50 degrees Fahrenheit (10 degrees Celcius)

Commonly referred to as budburst or bud break.

Question 13

Where are the buds located?

Answer 13

Buds are located between the vine stem & the leaf stem (petiole)

Question 14

What is primordia?

Answer 14

Organs in their earliest stages of development.

Question 15

What are the components of a dormant bud?

Answer 15

-Shoots
-Leaves
-Tendrils
-Flower Clusters (In some cases)

Question 16

What are lateral buds that produce flowers/fruit called?

Answer 16

Second Crop

Question 16

What happens if lateral buds don’t produce /grow in the current season?

Answer 16

The Die

Question 17

What is the Cap? (Calyptra)

Answer 17

A green structure that encloses the reproductive organs and other tissue within the flower.

Question 18

What is the female organ of the vine called?

Answer 18

Pistil (Cone Shaped)

Question 19

What is the male organ on the vine called?

Answer 19

Anther ( The anthers produce many yellow pollen grains, which contain the sperm)

Question 20

What is the tip of the female organ called?

Answer 20

Stigma (Slightly Flared)

Question 21

What is the Bloom Period & how long does it last?

Answer 21

The period in which flowers are open. (Bloom typically happens 50-80 days after bud bursts)

Bloom can last anywhere from 1-3 weeks depending on weather conditions.

Question 22

What is fetilization?

Answer 22

The successful union on the sperm & the egg.

Question 23

What is fruit set?

Answer 23

The growth of berries.

Question 24

Describe the Trunk.

Answer 24

The trunk was formerly an individual shoot After being trained as the trunk in a young vine, it became permanent and supports the above-ground vegetative (leaves & stems) & reproductive (flowers & fruits) structures of the vines.