Ch. 4 - Viticulture

Question 1

What is viticulture?

Answer 1

Viticulture is the term used for the branch of agriculture that specifically deals with the intentional cultivation of grapevines.

Question 2

Name the parts of a grape vine.

Answer 2

• Trunk
• Root System
• Branches
• Shoots
• Leaves
• Clusters

Question 3

What is a canopy?

Answer 3

The entire portion of the vine, i.e. spurs, canes, arms, leaves & grape bunches including the fruit, is referred to as the canopy.

Question 4

How is cloning carried out?

Answer 4

The grower can choose a healthy grapevine that is known to have desirable characteristics, cut off a short length of a young cane, place it in water where it will start to grow roots, and then plant it in the vineyard. This new plant will be a clone of the vine from which it was cut, genetically identical, and with the same desirable characteristics.

Question 5

How is field grafting carried out?

Answer 5

If there is an existing vineyard that is currently growing
an undesired variety of grapes. As long as the vine’s
rootstock (the major root system) is healthy, the grower can remove its existing branches, make a small incision in the trunk, and insert an unrooted cutting from a desirable vine. The rootstock will heal at the
wound site, and the cutting will begin to grow as if
it had been planted in the ground, except that it will
already have access to an extensive root network.

Question 6

When can a newly planted or grafted vine produce grapes for wine making?

Answer 6

The first crop of grapes to be used for wine is normally

harvested in the third year, which is sometimes called “third leaf”.

Question 7

Why is 30° and 50° latitude in both the Northern

Hemisphere and the Southern Hemisphere connsidered ideal for vine growing?

Answer 7

Generally 30° and 50° latitude in both the Northern
Hemisphere and the Southern Hemisphere bring the change of seasons causing long, warm-to-hot days in
summer, and short, cool-to-cold days in winter.

Question 8

Name the stages of the annual growth cycle.

Answer 8

• Weeping - Weeping occurs as
  the sap begins to flow upward from the trunk and out
  to the tips of the canes.
• Bud break - Tiny shoots called buds emerge from the nodes in the vine’s branches.
• Flowering - The next critical phase, takes place 40
  to 80 days after bud break. Clusters of tiny flowers
  appear at intervals along the shoots. Each flower that
  is fertilized will become the foundation for a grape.
• Berry set - The transition from flower to berry (grapes are sometimes referred to as berries, especially when immature).
• Veraison - The berries grow slowly for about a month
  and a half, at which point a major change in their physiological development takes place. It is most noticeable in red grapes, which begin to take on color at this time.
• Physiological maturity - Physiological maturity refers to the level of phenolic compounds in the grape, including tannins and other compounds that enhance the color, flavor, and aromas of the resulting wine.
• Harvest - Harvest generally takes place a month and a half to two months after veraison, when the grapes are
  ripe in terms of both sugar levels and physiological
  maturity.

Question 9

Which problems can occur during the growth cycle which can cause the berries to not form properly?

Answer 9

• Coulure - can cause poor fruit set, with many flowers failing to become fully developed berries.
• Millerandage (abnormal fruit set) - Sometimes caused
  by bad weather during flowering, results in grape
  bunches that have a high proportion of small seedless
  berries mixed in with the normal, larger, seedbearing
  grapes.

Question 10

How long is the duration from bud-break to harvest?

Answer 10

The time period from bud break to harvest is normally around 140 to 160 days but can be as short as 110 days or as long as 200.

Question 11

Name the fundamental processes of grapevine metabolism that have a direct impact on wine quality.

Answer 11

• Photosynthesis,
• Respiration,
• Transpiration,
• Translocation.

Question 12

What is Photosynthesis?

Answer 12

Photosynthesis is a process common to all green plants in which sunlight is used by the chlorophyll-containing (green) parts of a plant, primarily the leaves, to convert carbon dioxide and water into sugar.

Question 13

How is photosynthesis related to grape ripening?

Answer 13

The rate of sugar production, and thus the rate at which the grapes are filled with sugar, is directly related to the amount of photosynthesis that takes place. Photosynthesis depends primarily on two things: sunshine and temperature.

Question 14

What temperatures are favorable for photosynthesis?

Answer 14

Photosynthesis only occurs when the sun is shining,
and it slows at temperatures less than 50°F (10°C) or
greater than 95°F (35°C). Optimal sugar production
takes place on sunny days with temperatures between
70°F and 85°F (20-30°C).

Question 15

When does Respiration occur in vines?

Answer 15

Respiration occurs as the plant breaks down sugar and related carbohydrates, releasing their energy for use by the plant for activities such as root and leaf growth

Question 16

When sugar is not available what does the vine metabolize?

Answer 16

During veraison and at other times when sugar is unavailable, the vine shifts from metabolizing sugar to metabolizing malic acid (as well as trace amounts of other compounds) for energy.

Question 17

How does temperature affect the rate of respiration?

Answer 17

For every 18°F (-7°C) increase in temperature, the rate of respiration doubles. The warmer it is, the faster the plant respires and the quicker the acid level drops as the vine uses its acid for energy. For this reason, cool nights are usually beneficial for the ripening of grapes, as this will minimize the acid loss during a time when
photosynthesis is not taking place.

Question 18

What conditions are considered best for growing grapes?

Answer 18

For producing grapes that are rich in sugar and still
maintain a significant amount of natural acidity warm-but not hot-cloudless days and cool nights in a well-groomed vineyard that slopes downward, facing the sun.

Question 19

What is Transpiration?

Answer 19

Transpiration is the process by which water evaporates through openings on the underside of the leaves known as stomata.

Question 20

How is transpiration related to weather?

Answer 20

The rate of transpiration is closely linked to weather. It is highest under sunny, hot, windy, and dry conditions, and it is lowest under cloudy, cool, still, and humid conditions.

Question 21

How is availability of water related to transpiration?

Answer 21

The stomata will close if not enough water is brought in through the roots to meet the transpirational demand.Because these openings also control the intake of carbon dioxide, a shutdown of transpiration will also stop photosynthetic activity.

Question 22

What is Translocation?

Answer 22

Translocation is the process by which materials are moved from one area of the plant to another. Sugars, for example, are moved from the leaves, where they are made, to the growing shoot tips, roots, or trunk, where they are needed for energy.

Question 23

What is terroir?

Answer 23

The combined natural aspects of a vineyard, such as
climate, soil, sunlight, and water, can have a major
impact on the overall character and quality of a wine.
The French term for this, terroir.

Question 24

What is the difference between climate & weather?

Answer 24

Weather is the actual meteorological conditions experienced, whereas climate is the historical average weather of a place.

Question 25

What is a Macroclimate?

Answer 25

Macroclimate refers to the conditions of the overall region, and is roughly synonymous with climate. For instance, the effects of the Cascade rain shadow on the Yakima Valley AVA is an example of macroclimate.

Question 26

What is a Mesoclimate?

Answer 26

The term mesoclimate refers to what happens to a specific portion of the region, such as an entire vineyard.

Question 27

What is a Microclimate?

Answer 27

The term microclimat refers to the climate of a small portion of a vineyard, such as a few rows.

Question 28

What is a Canopy Microclimate?

Answer 28

The term canopy microclimate is used to refer to the environment within and directly surrounding a single vine’s canopy (or, at most, a small section of a single row).

Question 29

How much water does a vine require annually?

Answer 29

Vines need about 20-30 inches (51-76 cm) of water

annually, which they can receive through rainfall, irrigation, or a combination of the two.

Question 30

How does fertile soil affect vines?

Answer 30

In fertile soil, a vine has the tendency to produce an overabundance of shoots and bunches, with sugar and flavor components divided among too many grapes.
Theoretically, this can be controlled, but to do so requires considerable labor.

Question 31

How does infertile soil affect vines?

Answer 31

Less fertile soils encourage the vine to produce less vegetation and fewer grapes. This is part of the reason why, historically, grapes for wine have been planted in sites that were not amenable to the cultivation of other food crops.

Question 32

Describe various soil types defined by the sizes of particles.

Answer 32

• Clay: very fine particles that fit together so tightly
that water has difficulty passing through.
• Silt: particles of intermediate size.
• Sand: coarse particles with relatively little water retention capability.
• Gravel: larger pieces of solid inorganic matter;
essentially, inert obstacles that roots must pass
around, or sometimes through, to reach water and
nutrients.

Question 33

How does latitude affect vine growing?

Answer 33

In general, a lower latitude (that is, one closer to the equator) translates into hotter climates. Higher latitudes benefit from longer summer days and cooler nights, but they have a shorter growing season and possibly dangerous frosts and freezes.

Question 34

How does elevation affect vine growing?

Answer 34

Compared to a valley floor vineyard, a vineyard at a higher elevation will be cooler and windier, and may have less fog. Higher altitudes experience larger diurnal temperature swings, which is a positive factor as long as the nights don’t get too cold. Well above sea
level, the sunlight is more intense, encouraging photosynthesis.

Question 35

How does topography affect vine growing?

Answer 35

The way the vineyard is contoured can have any number of effects. Hillside vineyards have fewer problems with frost, but they can be harder to work if they are steep.

Question 36

How does aspect affect vine growing?

Answer 36

In the Northern Hemisphere, a vineyard on a slope that faces south gets the most sun, which is highly desirable in cool regions but not so desirable in hotter ones. In the Southern Hemisphere, the north-facing slopes get the most sun exposure.

Question 37

How does proximity to bodies of water affect vine growing?

Answer 37

Water tends to change temperature more slowly than soil. The larger the body of water, the more it resists
change. Their diurnal temperature range is less, summers are not as hot, and winters are milder compared to other vineyards at the same latitude but located farther from the water.

Question 38

What is maritime climate?

Answer 38

Maritime climates are strongly influenced by an ocean and have high rainfall and mild temperatures overall.

Question 39

What is continental climate?

Answer 39

Continental climates are the opposite: found in areas far from oceanic effects, they have hotter summers and colder winters-sometimes extreme in both directions-and they may have less precipitation.

Question 40

What is mediterranean climate?

Answer 40

Mediterranean climates, typically found within the temperate latitudes, are characterized by warm, dry summers, mild, wet winters, and low humidity.

Question 41

What is marginal climate?

Answer 41

Marginal climate which refers to an area that has such cool temperatures or such a short summer growing season that grapes are just barely able to achieve enough ripeness for harvesting before autumn frosts arrive.

Question 42

What are viral diseases?

Answer 42

Viral diseases can be spread by propagating infected
vine cuttings, so controlling them is dependent upon
avoiding introducing them to new vineyard plantings
or grafted vines.

Question 43

What are Bacterial diseases?

Answer 43

Bacterial diseases are more likely to be spread by insects and animals that carry the microbes.

Question 44

What are Fungal diseases?

Answer 44

Fungal diseases are generally spread by airborne spores and become a problem mostly in warm, humid conditions, which are ideal for the growth and spread of the fungus.

Question 45

What is Botrytis cinerea?

Answer 45

Botrytis cinerea, which, uniquely, can be as beneficial as it can be harmful.when it develops on fully ripe grape varieties that can benefit from it (white grapes, especially Semillon, Riesling, and Chenin Blanc), botrytis is known as noble rot. Botrytis is known to the French as pourriture noble and to the Germans as Edelfaule.

Question 46

How does Botrytis cinerea work?

Answer 46

Botrytis cinerea sends its filaments through the skin
of the grape to tap into the juice. By extracting water
from inside the berries, it concentrates the grapes’
sugars and flavors while adding its own characteristic
aroma, which has been described as being similar to
honeysuckle.

Question 47

What conditions are favorable for Botrytis cinerea?

Answer 47

Botrytis develops best under very special climatic conditions: morning fog, which provides a humid environment that nurtures botrytis growth on the berries, followed by afternoon sun, which prevents the fungus from spreading over the entire vine.

Question 48

Where does Phylloxera originate from?

Answer 48

Native to the eastern United States, phylloxera was
transported to Europe in the mid-1800s on the roots
of young vines of native North American origin.

Question 49

What is a nematode?

Answer 49

Nematode is a soil-based pest. This microscopic roundworm also feeds on the vine’s roots . In addition to causing direct damage to the vine via the worm’s feeding, nematodes also transmit viruses that can kill the plant.

Question 50

What are the preventive measures against nematodes?

Answer 50

The most common solution to the problem is the use of nematoderesistant rootstocks, but certain cover crops, such as mustard, can act as a natural biofumigant.

Question 51

What are the different types of prunings?

Answer 51

• Cane pruning - in which the grower allows one- or
two-year-old shoots (known as canes because they
have not yet become woody and bark-covered like
older branches) to remain; each cane is trimmed to leave about six to ten nodes, or buds.
• Spur pruning - in which several canes are left but
are trimmed to a length of only a few inches, containing just one or two nodes each.

Question 52

What is canopy management?

Answer 52

Techniques that alter the position or number of shoots and grape clusters are collectively known as canopy
management. Canopy management techniques include pruning, leaf trimming, the control of yield
and vine vigor, and the use of a vine training system.

Question 53

Describe Head training or bush training system.

Answer 53

No trellis is used, and the vine grows like a bush or miniature tree; spur pruning is the norm.

Question 54

Describe Guyot training system.

Answer 54

A simple cane-pruned system in which one cane from each vine in a row is trained along a wire, all of them in the same direction, to give maximum separation between grape bunches (single Guyot); alternatively, each vine may have two canes trained in opposite directions along the same wire ( double Guyot).

Question 55

Describe Cordon training system.

Answer 55

Same as Guyot, except spur-pruned. The branch or branches holding the spurs soon become as woody as the vine’s trunk, making it easy to tell the difference between an established cordon and a Guyot system.

Question 56

Describe Pergola training system.

Answer 56

Overhead vines are trained up a tall support and then allowed to spread out horizontally, with the fruit hanging down.

Question 57

For which systems is Vertical Shoot Positioning (VSP) used?

Answer 57

With Guyot or cordon systems, it is typical to see the use of the configuration known as vertical shoot positioning (VSP).

Question 58

Name the popular sugar measurement systems to anticipate the final alcohol level used by different countries.

Answer 58

• Brix - USA
• Baume - France
• Oechsle - Germany & Switzerland
• Klostemeuburger Mostwaage (KMW) - Austria

Question 59

What is organic viticulture?

Answer 59

Organic viticulture is grape growing without the

use of manufactured fertilizers or pesticides.

Question 60

What is Integrated Pest Management?

Answer 60

Integrated Pest Management is a targeted approach to dealing with pests in a vineyard. Its goal is to eliminate or control only those insects that are actually present and causing damage, rather than applying a more general solution that kills all insects, as some may in fact be beneficial.

Question 61

What is Biodynamic viticulture?

Answer 61

Biodynamic viticulture is essentially organic viticulture with the addition of metaphysical elements and a few mandated procedures.

Question 62

Who laid the foundations for biodynamic viticulture?

Answer 62

The philosophy of biodynamics, developed in the early twentieth century by Rudolf Steiner, is part of a larger movement that holds that all parts of the universe are interconnected as an ecosystem and that humans have the capacity to tap into the universal energy through meditation and mental practice.

Question 63

Which organization certifies Biodynamic vineyards?

Answer 63

Certification as a biodynamic vineyard is available through a private organization known as Demeter International.

Question 64

What is sustainable viticulture?

Answer 64

Sustainable viticulture has the same goals as organic and biodynamic viticulture, with one major difference in approach: it abandons the black-and-white criteria of the organic philosophy for a grayscale of relative value in protecting the environment.

Question 65

How is sustainable viticulture different from biodynamic and organic viticulture?

Answer 65

Sustainable viticulture is quiet different as neither organic nor biodynamic principles really address climate change and greenhouse gases, but sustainability does. Another example is water usage: organic practices do not address it, but sustainability recognizes that water is a scarce resource that must be used wisely.