Viticulture

Question 1

Describe six problems of excessive rainfall during the growing season

Answer 1

1. Flowering and fruit set rain can cause lack of pollination bringing a lower yield for that year.
2. If the vine has too much access to water during the growing season, the vine will continue to grow shoots and leaves during the ripening season. Leaving less sugars for the grapes
3. The extra shoots and leaves can cause shading restricting grape ripening
4. Waterlogged soils can cause roots to become saturated and die
5. Damp conditions that follow rainfall can also encourage the spread of fungal diseases
6. Rain shortly before harvest can cause the grapes to plump up and loose concentration of sugars, flavors, and acids leading to an undesirable wine. In extreme cases the grapes can split leading to more fungal disease

Question 2

Describe the affect of drought on the vine

Answer 2

The vine can temporarily stop transpiration in order to preserve resources and stopping photosynthesis, wilting leaves and the grapes fail to ripen. This can ultimately kill the vine

Question 3

What are the two problems of cloud cover during the growing season?

Answer 3

Low light levels, can cause problems during flowering and fruit set leading to low yields

Slowing the photosynthesis, can stop grapes from ripening fully

Question 4

Describe the affect of Sunburn on the vine

Answer 4

This can lead to bitter flavors developing in the grape skins

Question 5

Describe the affect of winter freeze

Answer 5

A vine can be damaged or killed, especially at the graft union is the most vulnerable

Question 6

Describe the affect of spring frost

Answer 6

It can kill newly burst buds or shoots reducing the yield and health of the vine

Question 7

List 3 management techniques for Spring frosts

Answer 7

Heaters
Wind machines
Sprinklers

Question 8

Describe a management technique for Winter Freeze

Answer 8

“Earthing up”. Where earth or soil can be used to cover up and protect the graft

Question 9

Describe management technique for Intense sunlight

Answer 9

The grape grower can manage the canopy to ensure enough shade is provided

Question 10

Describe a management technique for cloud cover

Answer 10

The grape grower can manage the canopy to ensure sunlight is maximized

Question 11

Describe a management technique for Drought

Answer 11

The grape grower can irrigate the vineyard if local laws permit

Question 12

Riesling thrives in cold climates, cane two reasons why it can grow in colder conditions

Answer 12

It is very tolerant of winters, buds late so it avoids spring frosts

Question 13

Describe a maritime climate

Answer 13

Cool to moderate temperatures, low continentality with rainfall evenly spread throughout the year.

Question 14

What is continentality?

Answer 14

Annual difference between hottest and coldest months

Question 15

What is Diurnal range?

Answer 15

The difference between hottest and coldest temperatures in a single day

Question 16

What is Continental climate?

Answer 16

Great difference between hottest and coldest months. Short, dry summers.

Question 17

What is Mediterranean climate?

Answer 17

Low temperature difference between the hottest and coldest months with warm, dry summers. Low rainfall

Question 18

What does pruning do?

Answer 18

Pruning is the removal of unwanted leaves, canes, and permanent wood. It shapes the vine and limits its size. This determines the number ad location of the buds what will for shoots in the coming season, impacting future yields. This can have an effect on the distribution of nutrients to the vine, spacing of the buds, which will allow for more even ripening.

Question 19

What does canopy management do?

Answer 19

Managing the green parts of the vine, which will ensure that grapes can either be protected from extreme heat to better exposed to sunlight.

Question 20

Why is it important to have grapes brought to the winery cold?

Answer 20

Cold grapes slow down the process of oxidation, which could lead to off flavors

Question 21

Give one solution to Nematodes in the vineyard

Answer 21

Sanitizing the soil before replanting and using resistant rootstocks have been found to be successful solutions

Question 22

What are Nematodes and what do they do?

Answer 22

Nematodes are microscopic worms that attack the roots of the vines interfering with water and nutrient uptake. They can transmit viruses.

Question 23

What conditions encourage Powdery Mildew?

Answer 23

It thrives in warm, humid environments

Question 24

What is a solution to Powdery Mildew?

Answer 24

Sulfur-based sprays and open vine canopies allow a greater air flow, which promotes evaporation and keeps them dry and possible.

Question 25

What is head grafting?

Answer 25

The existing vine is cut back to its trunk and a bud or cutting of a new variety is grafted onto the trunk.

Question 26

What are the advantages of head grafting?

Answer 26

Vine should be able to produce fruit from the new variety at the next vintage, which would take a newly planted wine 3 years. Much cheaper than replanting an entire vineyard.

Question 27

The Mistral is a hazard in Northern Rhone, how do grape growers combat this?

Answer 27

Supporting the vines with either individual stakes or tee-arrangments of stakes

Question 28

What is the dominant soil type in the Northern Rhone and why does it help produce premium Syrah?

Answer 28

Granite, it has low fertility so roots can grow deep and strong. Granite absorbs the heat provided and provides good drainage. This allows Syrah grapes to develop concentrated flavors w/out excess water filling the grapes