Ch. 4: Viticulture Flashcards
1
Q
Viticulture
A
Branch of agriculture that specifically deals with the cultivation of grapevines
Also called “winegrowing”
2
Q
Viticulture Facts
A
Grapevines cover nearly 19 million acres globally
Produce more than 70 million tons of fruit annually
70% goes into wine
3
Q
Vine Physical Structure
A
Trunk
Roots
Arms
Fruit
4
Q
Trunk
A
Connects its underground root system to the aboveground structure
Thickens over time, from slender to tree-like structure
Most trunks encouraged to have one or two arms
Branches
Shoots
Leaves
5
Q
Roots
A
Continue to grow throughout the lifetime of the vine
Capable of pulling water and nutrients from soil deep below surface
6
Q
Arms
A
One or two branches
Support leaves and grapes
Branches start out as “spurs”
Spurs develop into young, thin “canes”
7
Q
Canes
A
Most canes are removed during annual pruning
Canes that are retained and form thicker arms – “Cordons”
8
Q
Grapes (Fruit)
A
Seed repositories
Skin and pulp protect seed and nourish it
Green skin provides camouflage
Pulp is so acidic to dissuade consumption
Skin develops red or gold color as seed approaches maturity.
Encourages birds to eat grapes or carry them away
9
Q
Grapes are Ripe When…
A
Pulp is at maximum sweetness
Seeds are mature
10
Q
Seed
A
Represents a genetically unique entity
Drawing traits from both parents
Infinite, unpredictable variations possible
Takes a long time and high failure rate
11
Q
Cloning
A
Cut off short length of young cane
Place it in water
Starts to grow roots
Planted in the vineyard
More efficient than planting seeds
More consistent results
12
Q
Clone
A
New plant
Genetically identical to the plant from which it was cut
Same desirable characteristics
13
Q
Field Grafting
A
Grower removes existing branches
Makes small incision in trunk
Inserts unrooted cutting from desirable vine’
Rootstock heals
Cutting begins to grow
14
Q
Rootstock
A
Major root system of the vine
15
Q
Grapes from Newly Grafted Vine
A
During first or second season
Clusters of grapes are considered substandard
First crop of viable grapes harvested starting in third year
Called “third leaf”
16
Q
Twenty Years in Grapevine Life
A
Vine becomes less vigorous
Produces fewer clusters and leaves
Quality of the grapes improves
17
Q
Old Vine Wines
A
Wines made from vines 50 years or older
18
Q
Ideal Regions for Winegrowing
A
Between 30 and 50 degrees latitude in northern and southern hemispheres
19
Q
Growth Cycle
A
Weeping
Bud break
Flowering
Veraison
Physical maturity
Phenolic maturity
140 to 160 days
As short as 110 days, as long as 200 days
20
Q
Weeping
A
First sign of growth process
New greenery in spring
Temps rise above 50 degrees
Sap begins to flow upward from trunk out to tips of the canes
21
Q
Bud Break
A
Tiny shoots – buds – emerge from notes in vine’s branches
First critical event leading toward success or failure of vintage
Hazardous time, especially in cooler climates
Late frost can do serious damage
22
Q
Leaves
A
Shoots grow and strengthen
Plant draws upon carbohydrate reserves stored from previous year
Growth is slow
Leaves allow photosynthesis to begin
23
Q
Flowering
A
40 to 80 days after bud break
Clusters of tiny flowers appear along shoots
Self pollinating
Breeze blows pollen from one part of plant to another or to neighboring vines
24
Q
Ideal Weather for Flowering
A
Warm, dry
Rainy or windy conditions prevent pollen from reaching destination within flowers
25
Berry Set/Fruit Set
Transition from flower to berry
26
Coultoure
Can cause poor fruit set
Many flowers fail to become berries
27
Millerandge
Abnormal fruit set
Bad weather during flowering
Grape bunches have high proportion of small, seedless berries mixed in with normal ones
28
Grape Size
.5 to .75 inch in diameter
29
Veraison
Berry growth
Berries grow slowly for about 1.5 months
Major change in development takes place
30
Harvest
Takes place 1.5 to two months after veraison
Grapes are ripe
Reached physical and phenolic maturity
Early fall in warmest regions
Late fall/early winter in coolest regions
31
Phenolic Maturity
Level of character of certain phenolic compounds
32
Time Period from Bud Break to Harvest
Normally 140 to 160 days
Can be short as 110 or long as 200 days
33
Dormant State
Vine drops its leaves
Withdraws sap from branches and shoots
Moves to trunk and roots
Growers will conduct winter pruning
34
Metabolic Processes
Photosynthesis
Respiration
Transpiration
Translocation
35
Photosynthesis
Sunlight is used by the chlorophyll-containing parts of the plant – leaves – to convert CO2 and water into sugar
Sugars are the basic building block of most materials found in vine
Amount of photosynthesis = amount of sugar
Depends on sunshine and temperature
36
Optimal Sugar Production
Takes place on sunny days
Temperatures between 70 and 85 degrees
37
Ideal Conditions for Photosynthesis
Warm Days
Long days
Clear days
Minimal shading
Southern or northern aspect
38
Respiration
Plant breaks down sugar and related carbohydrates
Releases energy for use by plant
Root and leaf growth
Continues throughout growing season
39
Malic Acid Respiration
Plant metabolizes malic acid if sugar not available
Early on, grapes are full of malic acid
After respiration, acid levels are much lower
40
Respiration and Temp
Respiration rate affected by temp
For every 18-degree increase, rate doubles
The warmer it is, the quicker the acid level drops
Cool nights beneficial for grape ripening
Warm to hot afternoons and cool to cold nights allow for maximum photosynthesis and acid retention
41
Best Conditions for Producing Grapes
Warm, but not hot
Cloudless days
Well groomed vineyard
Slopes downward, facing sun
42
Transpiration
Water evaporates through openings on underside of leaves – stomata
Closely linked to weather
43
Stomata
Openings on underside of leaves
44
Transpiration – Highest Rate
Sunny, hot, windy, dry conditions
45
Transpiration – Lowest Rate
Cloudy, cool, still, humid conditions
Stomata will close if not enough water is brought through roots to meet demand.
Shutdown of transpiration stops photosynthesis
46
Translocation
Materials moved from one area of the plant to another
Sugars moved from leaves to growing shoot tips, roots, or trunk
47
Terroir
Combined natural aspects of vineyard
Climate
Soil
Sunlight
Water
48
Weather
Meteorological conditions experienced
Most changeable and uncontrollable of winemaking variables
Biggest factor that causes variation in vintages
Vineyard site selected based on climate, but weather might not cooperate in a particular year
49
Climate
Historical average of weather of a place
Long-term consideration
50
Macroclimate
Conditions of the overall region
Synonymous with ‘climate’
51
Mesoclimate
What happens to a specific portion of the region
Like the vineyard
52
Microclimate
Small portion of the vineyard
53
Canopy Climate
Environment within and directly surrounding a vine’s canopy
54
Importance of Micro and Mesoclimate Distinction
Small differences in climate can account for significant differences in resulting fruit
55
Climactic and Weather Features
Temperature
Precipitation
Humidity
Fog
Wind
Soil
Physical geography
56
Temperature
Great effect on sugar-acid balance in grapes
Helps determine quality of vine
High temps = poor balance
Cold temps can also be significant
57
Winterkill
Ground is frozen several feet down
58
Precipitation
Vines need 20-30 inches of water annually
Through rainfall, irrigation, or combo
Unwelcome during harvest
Water swells and dilutes berries
Hail can wipe out crop if strikes after veraison
59
Humidity
Perfect conditions for growth of fungus and mold
Can degrade quality of grapes
May increase need for fungicides
60
Fog
Can be good or bad
Can reduce temps and sunlight – beneficial in hotter climates
Raises humidity – not harmful when burned off
Can create ideal conditions for Botrytis cinera fungus
61
Wind
Can be good or bad
Can interfere with flowering and pollination
Can put strain on vines
Windbreaks used in some locations
Can be beneficial by reducing humidity and pest concerns
62
Types of Soil
Clay
Chalk
Sand
Gravel
Silt
Slate
Marl
Loess
Limestone
63
What World’s Greatest Vineyards Have in Common
Not very fertile
Soil regulates the supply of water to vine
64
Clay Soil
Very fine particles that fit together tightly
Water has difficulty passing through
65
Silt
Particles of intermediate size
66
Sand
Coarse particles
Little water retention capability
67
Gravel
Larger pieces of solid inorganic matter
Obstacles that roots must pass around to reach water/nutrients
68
Minerals in Soil
Quartz
Feldspar
Calcium carbonate
Also decompose plants/animals
69
Physical Geography
Elements cannot be exactly duplicated anywhere else
Distance from ocean
Contour of land
Latitude
Proximity to mountains, rivers, etc
70
Geographic Factors
Latitude
Elevation
Topography
Aspect
Proximity to bodies of water
71
Latitude
Lower latitude = hotter climates
Higher latitudes – Longer summer days/cooler nights, shorter growing season, possibly dangerous frosts/freezes
72
Elevation
Higher elevation – cooler and windier, maybe less fog
Higher elevation – larger daily temp swing
OK if not too cold
Well above sea level – intense sunlight, encouraging photosynthesis
73
Topography
Way vineyard is contoured
74
Hillside Vineyards
Have fewer problems with frost
Harder to work if steep
75
Flat Bottomland Vineyards
Can be overly fertile
76
Rolling Topography
Can create patchwork of low areas that collect too much water
Higher areas are always dry
77
Aspect
Northern hemisphere – Vineyard facing south gets most sun
Southern hemisphere – Vineyard facing north gets most sun
78
Proximity to bodies of water
Vineyards located near water have far less temp variation
Summers not as hot, winters are milder
Provide source of humidity
Can mean fog, cloud coverage, fungus-encouraging dampness
79
Maritime Climates
Strongly influenced by an ocean
High rainfall
Milder temps
80
Continental Climates
Far from ocean
Hotter summers
Colder winters
May have less precipitation
81
Mediterranean Climates
Warm, dry summers
Mild, wet winters
Low humidity
High pressure atmospheric cells
82
Marginal Climate
Area with cool temps or short summer growing season
Grapes just barely able to achieve enough ripeness for harvest
83
Diseases
Caused by viruses, bacteria, or fungi
Most troublesome at specific times of the year
84
Areas of the Vine Attacked by Disease
Roots
Trunk
Branches
Shoots
Flowers
Grapes
85
Viral Diseases
Spread by propagating infected vine cuttings
86
Bacterial Diseases
Spread by insects and animals that carry the microbes
87
Pierce's Disease
Results in premature leaf fall
Spread by sharpshooter insects
Most common – Glassy-winged sharpshooter
Might feed on infected vine then carry bacteria to healthy fine
Controlled by insecticides
88
Fungal Diseases
Spread by airborne spores
Become a problem in warm, humid conditions
Sulfur or commercial fungicide
Most damaging fungal diseases
89
Odium Fungus
Powdery mildew
90
Peronospora Fungus
Downy mildew
91
Botrytis Cinerea
Noble rot
Can be beneficial or harmful
Gray mold wreaks havoc on ripening grapes
Beneficial when it develops on fully ripe grapes
Sends filaments through grape skin
Extracts water from the berries
Concentrates grapes’ sugars/flavors
Adds its own aroma – honeysuckle
92
Botrytis Optimal Conditions
Morning fog followed by afternoon sun
93
Botrytis – France
Pourriture noble
94
Botrytis – Germany
Edelfaule
95
Pests
Phylloxera
Nematode
96
Phylloxera
Native to eastern US
Accidently introduced to Europe in mid 1800s
Devastated many vineyards
Made its way to other parts of the world
97
Phylloxera Solution
Native American grapevines developed natural resistance
Attempt to interbreed these vines with vitis vinifera
Many hybrids were deemed unsatisfactory
Prized vines grafted onto rootstock of American vines
Most destroyed vineyards were replanted with grafted vines
Only a few vineyards in the world are phylloxera free
98
Nematode
Microscopic roundworm
Feeds on roots
Transmit deadly viruses
99
Risk of Nematode
Increased use of shallow-rooted rootstocks
Use of drip irrigation – reduces vine’s tendency to send roots deep in soil for water
100
Nematode Solutions
Nematode-resistant rootstocks
Cover crops – mustard
101
Pruning
Performed in winter or early spring
Removal of much of the vegetative growth from previous year
Removal all but a few nodes
Also excess foliage and branches
Need to manage size, shape, development of vine
102
Benefits of Pruning
Number of shoots and branches would generate naturally is much higher than desirable
Uncontrolled leave and fruit production would spread nutrients to thinly
103
Cane Pruning
Remove all but one or two canes per vine
Remaining canes attached to horizontal trellis, trimmed
Each cane has six-ten nodes
104
Spur (cordon) Pruning
Vines trained to develop one or more permanent cordons (branches)
Each branch will support several canes
Cut back new canes, leaving behind several spurs
105
Spur
Portion of a cane
Contains several nodes (buds)=
106
Trellised Vines
Use training system
One or two canes or cordons trained along a wire
Use vertical shoot positioning (VSP)
107
Vertical Shoot Positioning (VSP)
New year’s shoots and leaves are trained upward
Braced by trellis during growth
108
Benefits of VSP
Good air circulation
Light exposure
Ease of use with mechanical harvesting
109
Bush Vines
Vines that develop a thick trunk
Typically freestanding
Gobelet style vines
110
Pergola System
Overhead vines trained up a tall support
Allowed to spread out horizontally
Fruit hangs below
111
Canopy Management
Techniques that alter the position or number of shoots and grape clusters
Optimize fruit quality through control of vine yield and vigor
112
Types of Canopy Management
Shoot thinning
Shoot positioning
Leaf removal
Crop thinning
113
Irrigation
Vines might require supplemental water to maintain rate of growth
Also fertilizers or chemical nutrients
114
Managing the Harvest
Grower must decide on optimal time to harvest grapes
Based on ripeness and style of wine to be produced
Also weather, labor availability, and economic considerations
115
Concentration of Sugar Measurement – US
Degrees Brix
Refractomeeter or hydrometer used
Potential alcohol = Brix reading/2
116
Baume
Measurement of potential alcohol
France
Alcohol level in millimeters per 100 millimeters of wine
117
Oechsle
Measurement of potential alcohol
Germany and Switzerland
118
Organic Viticulture
Grape growing without use of manufactured fertilizers or pesticides
Organic viticulture recognition
Certification process overseen by accredited body
State agricultural department or sanctioned private company
119
Organic Viticulture Certification – US
USDA National Organic Program
Vineyard must be free from all prohibited materials for minimum of three years
120
Organic Methods
Compost and manure vs. chemical fertilizers
Additional mowing vs. herbicides
Sulfur mixes as fungicides
Natural predators
121
Integrated Pest Management (IPM)
Targeted approach to pest management
Eliminate/control only those insects that are present and causing damage
Each pest is considered individually
122
IPM Considerations of Pests
Life cycle
Natural predators
Hosts
Used to determine vulnerabilities
123
Biodynamic Viticulture
Organic viticulture + metaphysical elements
Vary among grape growers
124
Biodynamics History
Early 20th century
Rudolf Steiner
All parts of universe are connected as ecosystem
Humans can tap into universal energy
125
Certification of Biodynamic Status
Private organization
Demeter International
126
Sustainable Viticulture
Same goals as organic/biodynamic
Grower shows commitment to long-term future of environment, society, and winegrowing
Abandons B&W criteria for a grayscale of relative value in protecting environment
Leave the land better for the next generation
Doesn’t provide set of rules
127
Examples of Sustainable Methods
Infrequent applications of mild herbicides
Water usage used wisely
128
Sustainable Viticulture Organizations
Lodi Rules Sustainable Winegrowing Program
Napa Green Certified Vineyard/Winery
