L3 Chapter 6 -Vineyard Management

Question 1

What conditions factor into a grape grower’s site selection?

Answer 1

(1) ENVIRONMENTAL FACTORS

-potential average temperature, rainfall, sunlight, fertility of soil, and how well soil drains
-this will influence what choice of grape variety can grow, as well as, planting density and systems of trellising

(2) BUSINESS CONSIDERATIONS

-proximity of vineyard to utility infrastructure (power/water),
-availability of vineyard workforce,
-accessibility of site for machinery
-cost of the land

(3) GRAPE VARIETY

-must suit the climatic conditions of the preferred site
-demand for grape variety
-EU restrictions on grape varieties

Question 2

How is a new vineyard planted?

What should be done to the soil before a new vineyard is planted?

Answer 2

Usually young vines are bought pre-grafted and planted either by hand or machine. They are protected with plastic sleeves.

Before planting the vineyard site should be cleared of existing vegetation and soil tested to correct nutrient deficiencies

Question 3

When does first yield of a new vineyard come?

Answer 3

Typically in the 3rd year after planting

Question 4

When are the majority of vines replaced?

Answer 4

Vines can live a long time, but most are replaced between the ages of 30 and 50 years old.

Vineyards are typically left to fallow (unplanted) for 3 years after vines are dug up, to allow the land to recover

Question 5

What are “old vines”/vielles vignes?

Answer 5

Vines that are typically older than 50 years.
Wine is made from well-established plants and thought to produce, concentrated flavors, and fruit of exceptional quality.

-The yields of old vines, however, produce a smaller yield of fruit and can be susceptible to disease.

Question 6

How are vines managed in the vineyard?

Answer 6

Grape growers manage a vineyards vines in relation to the vineyards resources (sunlight, temperature, water, and nutrients) using:

-training
-pruning
-trellising
-density of the planting area

Question 7

What are the 2 types of vine training?

Explain what each of the differences of each of these.

Answer 7

Vine training refers to the shape of the permanent wood

Two types:

-HEAD TRAINING which has relatively little permanent wood some only.a trunk, or a few short arms of perm wood growing from the trunk)

(can be spur-pruned or replacement cane-pruned)

-CORDON TRAINING- typically have a trunk with one or more permanent horizontal arms. (usually spur-pruned).

cordon training takes longer but is sturdier and easier to use machine harvesting

Question 8

What are the two types of winter vine pruning?

Answer 8

(1) Spur pruning

-can occur on either a head trained or cordon trained vine

-typically seen in warmer climates (California, Washington, and Spain)

-easier to prune

-more traditional method for old vine wines

(2) Replacement cane pruning or guyot pruning

-occurs on a head trained vine

-typically seen in cooler climates (Burgundy, Sonoma, and Oregon)

-by limiting the amount of permanent wood the vine is better protected from frost

-requires a high degree of skill to prune in this way, so typically only seen in prestigious vineyards

Question 9

What is the purpose of winter pruning?

Answer 9

Its main purpose is to determine the number and location of the buds that will form shoots in the coming growing season.

Buds should not be close together.

Question 10

What is the purpose of summer pruning?

Answer 10

Summer pruning involves trimming canopy to restrict vegetative growth so that it can direct nutrients to sugar production of the grape.

Can also involving stripping leaves to give grape bunches more exposure to sunlight.

Question 11

How are trellises used to manage a vine canopy?

Answer 11

Two choices:

(1) untrellised vineyards

-Vines have no trellis and the shoots hang far down and as low as the ground

-best suited for warm/hot/dry/sunny regions like the Southern Rhone or Barossa Valley (Aus) - extra shade helps protects grapes

-not good for cool/wet regions where shade impedes ripening and can promote disease

(2) trellised vineyards

-each row of vines/cane shoots is tied to a line of trellis wires

Question 12

What are 3 benefits of trellis training?

Answer 12

Most beneficial for cool/wet climates

(1) Can be used to control/increase the amount of sunlight that gets into the canopy to aid grape growth. Creating an “open canopy” maximizes sunlight helping grapes ripen successfully

(2) Open canopies increase circulation among the leaves which can help prevent fungal diseases -important in wet climates

(3) can make mechanization in vineyards easier to achieve/spraying of pesticides more effective

Question 13

What is the most widely used trellising system?

Answer 13

Vertical Shoot Positioning (VSP)

VSP is the process of training vine shoots vertically into a single, narrow, canopy.

Keeps canopy as open, well-aerated and shade free as possible

Question 14

How can VSP be adjusted in warmer climates?

Answer 14

In warmer climates the top of the shoot is not tied to the trellis and allowed to flop over to provide some shade.

Question 15

What is planting “density”?

Answer 15

The number of vines planted in a given area (ie. per hectare -a square with 100 meter sides)

low density may be 1000 vines per hectare while high density my be 10,000

Question 16

What is a key factor in deciding planting density?

Answer 16

The amount of water and nutrients available.

Question 17

How should vine density be approached for low rainfall regions?

Answer 17

-In regions with low rainfall/limited access to irrigation- density will be low to allow vines ability to take advantage of water in soil without having to compete.

Question 18

How should vine density be approached for low nutrient, and sufficient rainfall regions?

Answer 18

Where the soil is low in nutrients but gets sufficient rainfall - vines may grow vigorously/produce vegetation. In this situation high density is preferred so that vines are competing for resources and directing to grape growth.

Here winter pruning is important as well. Too few buds means the vines will have too much access to energy, whereas too many means they won’t have enough nutrients and will struggle to ripen.

(Common in European vineyards)

Question 19

How should vine density be approached for high nutrient, and sufficient rainfall regions?

Answer 19

-here high density planting is not enough to limit the vine vegetation growth

-instead systems of low density planting plus multiple cordons/canes used.

Allows for high yields of good quality

Question 20

What are nematodes?

Answer 20

Microscopic worms that attack the roots of the vines interfering with water and nutrient uptake

Question 21

What is downy mildew?

Answer 21

A fungus that thrives in warm, wet conditions.

Yellow spots on top of leaves and grey fuzzy patches under leaves. Can cause leaves to drop or reduce grape yields

Question 22

When and at what temperature does bud burst begin?

Answer 22

Bud burst is the start of the season

It typically begins when the daily mean temperature exceeds 50 F (10C) .

This can depend on the variety. Pinot Noir/Chardonnay are early budding, but Cab Sauv is late budding and needs a warmer climate.

Question 23

What is the biggest risk for early budding varieties?

Answer 23

New shoots can be susceptible to spring frosts, reducing yields

Question 24

What are the 6 periods of the vineyard cycle?

Answer 24

(1) Winter Dormancy
–Dec to March -Northern Hemisphere
–June to Sept - Southern Hemisphere

winter pruning takes place, vines become dormant. earth may be piled up to protect against deadly extreme winter freezes.

(2) Budburst
–March to April -Northern Hemisphere
–Sept to Oct - Southern Hemisphere

Occurs when the mean daily temperature exceeds 10C (50F)

(3) Early Shoot and Leaf Growth
–March to May -Northern Hemisphere
–Sept to Nov - Southern Hemisphere

Photosynthesis begins. Vine needs good water & nutrient supply. Trellising may begin here, if practiced.

(4) Flowering and fruit set
–May to June -Northern Hemisphere
–Nov to Dec - Southern Hemisphere

At this time vine needs warm temps & little to no rain, otherwise pollination will be disrupted, reducing fruit set.

(5) Veraison and Berry Ripening
–July to Sept -Northern Hemisphere
–Jan to March - Southern Hemisphere

6-8 week period where grapes start to grow. Veraison signals grapes ripening. Skin color changes. Sugar levels rise and acidity drops as grapes swell & fill with water.

Warm & sunny conditions ideal.

(6) Harvest
–Sept to Oct -Northern Hemisphere
–March to April - Southern Hemisphere

Ideally conditions are dry during this time, to prevent grapes from swelling & diluting flavors and/or to prevent damp conditions which cause rot.

Question 25

When does spraying for fungal diseases begin?

Answer 25

Spraying of pesticides typically begins at budburst and will continue into early shoot growth, flowering & fruitset, and even veraison. It must have stopped in time for harvest to ensure no harmful chemical residues

Question 26

What is coulure?

Answer 26

Where more flowers than normal drops off in the fruit set (due to being unpollinated). This like millerandage reduces yields and usually stems from cold, cloudy, rainy weather.

Question 27

What is millerandage?

Answer 27

When grapes form without seeds and remain small. This like coulure reduces yields and usually stems from cold, cloudy, rainy weather.

Question 28

What is powdery mildew?

Answer 28

A fungus that thrives in warm, shady conditions with humidity. Severe infections can cause leaves to dry up and drop off the vine prematurely.

Infected grapes shrivel and split

Question 29

What is grey rot?

Answer 29

Caused by the fungus botytis cinerea, which thrives in damp conditions. In black grapes it taints flavors and leads to color loss.

In white grapes it can be beneficial to producing sweet wines (noble rot).

Question 30

How are fungal diseases controlled?

Answer 30

Using chemical sprays, usually done by tractor. More sprayings required in maritime climates where there is more rainfall during the growing season.

For powdery mildew = sulfur based spray

For downy mildew = copper based spray

Canopy management (particularly an open canopy) helps to manage fungal disease. Closed canopies restrict airflow, but open allow for greater airflow which promotes evaporation and keeps it dry as possible

Question 31

What risks do viruses pose to vines?

Answer 31

They limit the vines ability to function and dramatically reduce yield and quality. Highly contagious/persistent, usually spread by cuttings or nematodes. No treatments or cures. Can only be eradicated by digging up the vines and sanitizing the land.

Most do not kill vines

Question 32

What risks do bacterias pose to vines?

Answer 32

They reduce grape quality and quantity. Some can kill vines. Typically spread by small insects called sharpshooters.

Strict quarantines can prevent the disease. No treatments or cures. Can only be eradicated by digging up the vines and sanitizing the land.

Question 33

What are 3 practices used to reduce the quantity of chemicals/pesticides used?

Answer 33

(1) SUSTAINABLE agriculture

(2) ORGANIC agriculture

(3) BIODYNAMIC agriculture

Question 34

What are sustainable agriculture practices?

Answer 34

-Use of man-made chemicals is restricted (not prohibited)

-grape growers are encouraged to understand lifecycles of pests & monitor weather to predict/prevent outbreaks before they occur.

-Rather than have a regular schedule of spraying, spraying occurs at times when it will have the most impact resulting in fewer sprays.

-integrated pest mgmt also used. (ie. encouraging predators of certain pests to live in the vineyard, adn bringing a range of plants that can provide habitats for predators of pests

Question 35

What are organic agriculture practices?

Answer 35

-Similar practices to sustainable, but even less chemicals are allowed and in very small quantities.

-accreditation is required from an organic certified body (however, rules vary and some are more strict than others)

-Universally required however, is that the they must undergo a period of “organic conversion” working to organic standards before they are certified

Question 36

What are biodynamic agriculture practices?

Answer 36

-Based on the work of Maria Thun and Rudolf Steiner

-Adopts practices but also incorporates philosophy and cosmology.

-The vineyard soil is seen as part of a connected system with the planet earth, air and other planets. Grape growing coincides with planet, moon and star cycles.

Homeopathic remedies called “preparations” are used to fertilize soil, treat diseases, ward off pests

Question 37

What happens at veraison?

Answer 37

Grapes begin to ripen. Acid drops and sugars rise. Grapes also develop signature flavors and tannins in skins become less bitter and astringent.

The ideal balance of sugar, acid, flavor, and tannin will depend on the climate, grape variety, and style & quality being produced.

Question 38

When does harvest begin?

Answer 38

Ideally when a grape grower believes the grape has the exact qualities of acid, sugar, flavor and tannin that they need to create the desired style of wine.

However, bad weather may cause a grower to harvest early (ie. to avoid hail which can cause grapes to swell & dilute juice)

Question 39

How is harvesting typically done?

Answer 39

Either by hand or machine harvesting. This will depend on a number of factors:
-labor availability and cost
topography of the vineyard, weather conditions, and winemaking choices

premium wines can be made both by hand and machine harvesting

Question 40

How does machine harvesting work?

Answer 40

Machine harvesters shake the trunk of the vine and collect ripe berries as they fall off, leaving stalks behind. (not selective like hand harvesting, so damaged/diseased grapes can be collected).

Unwanted grapes are removed during sorting when they arrive at the winery (unless large scale winery and not possible)

-speed is a key advantage with machine harvesting -esp if vintage is threatened by bad weather.

-machines can also run at night, allowing cool grapes to be brought to the winery, slowing process of oxidization, and saving money/energy on cooling grapes pre-fermentation.

-can only be used on flat or gentle slopes -best suited to varieties that are not easily damaged

-Cannot be used to pick grapes for wine styles that require whole bunches (ie. Beaujolais)

Question 41

How does hand harvesting work?

Answer 41

Involves pickers cutting off individual bunches of grapes with secateurs.

Stems are retained

More labor intensive & expensive

-BUT allows for grape selection to take place in the vineyard. Rotten/unripe grapes can be left on the vine.

-essential for noble rot, because the onset and level of rot can vary by bunches, meaning careful selection is needed.

-Also tends to cause less damage than machines, and can further protect grapes by placing them in shallow, stackable trays

-May be the only option available for steep vineyard slopes (ie. Douro valley, Mosel, northern rhone slopes)

For white wines: allows for whole, intact grapes which can produce a purer, cleaner juice when pressed

For red wines: essential in whole bunch fermentation