Viticulture Flashcards
What percent of total grapes grown go into wine?
70%
What is the term for the branch of agriculture that specifically deals with the intentional cultivation of grapevines?
Viticulture
What is the core of a grapevine called?
The trunk
The trunk of the vine connects the root system of the grapevine underground, to the above ground system of _____, ______, and _____
Branches, shoots, and leaves
What are the one or two branches that sprout from the trunk called?
Arms
The arms of the trunk when first formed are called ____, which eventually turn into thin _____, and then thicker arms or ______
Spurs, canes, cordons
What is the typical amount of arms encouraged on a trunk?
One or two
On which part of the grapevine to grape bunches grow?
The arms
What is the entire portion consisting of arms, leaves, and grapebunches called?
The canopy
When grapes are young, to protect the seeds inside, they are green and taste too _____
Acidic
As grapes age, they go from green to _____
Gold or red/purple
Planting seeds commercial is often considered too unpredictable and lengthy, so a common method for propagation is ____
Cloning
What portion of the grape vine will be cut to produce a clone?
A cane
What is done to the cane of the grape vine in order to propagate the original?
The cane is cut, placed in water so that it will grow roots, and then planted
What is field grafting?
Removing branches from a grapevine producing an undesirable variety, making incisions on the trunk, and inserting an unrooted cutting from a desirable variety into the incision
During what year of a grapevine’s lifespan is the first crop of grapes harvested?
The third year
What is the first crop harvest period also known as?
Third leaf
While there is contentious debate, what is the generally accepted amount of aging required for a grapevine to produce optimal quality grapes?
Six years
What happens to the quantity and quality of grapes as the plant roots age?
The quality of the grapes is said to improve, but the quantity diminishes.
What macro climate is considered ideal for wine growing?
Temperate climates
In between which latitudinal measurements is wine growing ideal?
Between 30 and 50 degrees in both the Northern and Southern hemisphere.
How many months apart are the harvest cycles in the Northern an Southern hemispheres?
About 6 months
What is the period in the Spring during which the process of grape growing begins called?
The weeping
At what ground temperature in the spring does the process of the growing cycle begin
50 degrees F/10 degrees C
What is occurring on the plant during the beginning of the weeping?
Sap grows upward from the trunk towards the tips of the canes
How long does the process of the weeping take?
Only a day or two
After the weeping, when tiny shoots called buds begin to emerge from vine nodes, what is this period called?
Bud break
Why is bud break a critical part of the harvest cycle
Buds are delicate and really susceptible to temperature fluctuations like frost
Before buds begin to produce leaves, from where does the plant derive its carbon dioxide for nourishment?
From CO2 stored during the previous year
When does the growth of the plant really begin to accelerate?
When leaves begin to form so that photosynthesis can occur, and plants can derive energy directly from the sun
What is flowering?
When small clusters of flowers begin to form at intervals along the shoots
When does flowering take place?
Between 40 and 80 days after bud break
How are grape vines pollinated?
They self pollinate
How is the seed (encased in the grape) formed?
When pollen is blown in breeze from one portion of a plant to another, or from a neighboring plant, and the flower is fertilized
What type of weather is ideal during flowering?
Warm, dry weather
What is the transitional period between flower and berry called?
Berry set or fruit set
What is the malady for when flowers fail to transition to grapes called, and what does that mean in English?
Coulure, meaning ‘shatter’
What is the abnormal condition called when grape bunches have small, seedless grapes mixed in with the large, normal ones?
Millerandage
What can cause millerandage?
Bad weather
About how long does it take for tiny grapes to grow into their full size?
About three months
What are the grapes like at first after transitioning from tiny to mature?
Green, dull, hard, and highly acidic
What is the term for the sudden transition of grapes from young to mature at an accelerated rate?
Veraison
When does harvest take place relative to veraison?
Approximately a month and a half to two months later
What about a grape measures its ‘physiological maturity?
The levels of phenolic compounds, including tannins and the rest
What two components of a grape determine its ripeness?
Its sugar levels and its ‘physiological maturity’
What is the typical amount of time between bud break and harvest?
Between 140 to 160 days
What are the extreme low and high range of days between bud break and harvest?
As quickly as 110 days and as late as 200 days
During what season does harvest occur?
Fall
What state does a vine enter during cold autumn nights?
A dormant state
What happens to the plant during its dormant state?
The leaves drop, and the sap retreats into the trunk and roots where it is less susceptible to damage during freezes
What do wine growers do to the vine during its dormancy?
They prune it, reducing most of the year’s growth to keep it manageable and ensure an appropriate yield the following year
At what age do vines begin to decline?
20 years
What is the process by which the vine produces sugar?
Photosynthesis
What is the process by which the vine uses energy?
Respiration
What is the process in which water evaporates through openings in the vines leaves?
Transpiration
What is the process by which materials such as sugars are moved from one area of the plant to another?
Translocation
What is the major root system of a vine called?
Its rootstock
On what two things does photosynthesis depend?
Sunlight and temperature
Between what two temperatures is photosynthesis possible?
Between 50 and 95 deg F
What is the optimal temperature range for sugar production?
Between 70 and 80 deg F
During veraison or other times during which sugar is unavailable for energy, vines begin metabolizing what?
Malic acid
For every ____ deg F in temperature increase, the rate of respiration doubles
18 deg F
What are the openings on the underside of the leaves called?
Stomata
Transpiration, analagous to perspiration in animals, serves what purpose?
Cools the plant down
What is the French word for the combined natural aspects of a vineyard?
Terroir
What is the difference between climate and weather
Weather is the actual meteorological conditions experienced, while climate is the historical average weather of a place
What are the three subdivisions of the term “-climate”?
Macroclimate, mesoclimate, and microclimate
As temperature increases, it causes ____ levels to rise, and _____ levels to drop.
Sugar levels rise, acid levels drop
How many inches of water per year do vines need?
20-30 inches
Rain is not welcome during harvest because it does what to berries?
It causes them to swell, and dilutes their sugar content
Why is high humidity bad?
It could cause fungal growth and diminish quality of grapes?
Why can fog be beneficial?
It can cool down grapes during hot days
What is the fungus called, that fog is an ideal condition for, that is required for certain dessert wines?
Botrytis cinerea
What are two ways in which wind can be disruptive to wine growing?
It can put a lot of undue strain on vines, or interfere with flowering or pollination?
What are two negatives can be reduced by wind?
It can reduce humidity and the impact of pests
Are grapes better suited to fertile or infertile soil? Why?
Infertile soil; because with fertile soil there might be an overabundance of shoots and bunches, and therefore the sugar and flavor components are overly divided.
What is s ‘soil type’ defined by?
The sizes of particles it contains and the composition of said particles
What are four major particle ‘sizes’ of soil?
Clay, silt, sand, gravel
What are five categories of physical geography that might help define terroir?
Elevation, latitude, topography, and aspect, proximity to bodies of water
Lower latitude translates typically into what type of climates?
Hotter climates
Do vineyards located near bodies of water experience MORE or LESS variance in temperature
Less variance
What are the three primary categories of ‘climates’ relevant to the wine world?
Mediterranean, continental, maritime
What are three defining characteristics of a maritime climate?
There is strong influence from the ocean, high rainfall, and mild overall temperature
How are the summers and winters of a continental climate, temperature wise? And the precipitation?
Hotter summers, colder winters, and little rainfall
How would one characterize the summers, winters, and humidity of a Mediterranean climate?
Warm, dry summers, wet mild winters, and low humidity
What is a type of climate called that has such short summers or cool temperatures that there is barely enough time for grapes to ripen?
Marginal climate
What are three causes of grapevine diseases?
Bacteria, fungus, and viruses
How can viral diseases spread among vines?
By propagating with infected cuttings
How are bacterial diseases likely to be caused?
By animals and insects that carry microbes
What is Pierce’s disease?
A bacterial infection of the host vine resulting in premature leaf fall
What types of insects can spread Pierce’s disease?
Different species of sharpshooter insects
What causes fungal disease?
Airborne spores
What types of conditions lend themselves to fungal disease?
Warm, humid conditions
What are two of the most damaging fungal diseases
Powdery mildew, aka oidium, and downy mildew aka peronospora.
What is the type of fungus that can be both harmful and beneficial to grapes?
Botrytis cinerea
When Botrytis is being harmful, it is known as what
Gray mold
When Botrytis is being helpful or intentionally used, it is known as what
Noble rot
What do the French and the Germans call Botrytis
French: Pourriture noble | Germans: Edelfäule
How does Botrytis act on grapes?
It sends filaments into the skin of the grape to extract water
What impact does Botrytis have on a grape?
It concentrates a grapes sugars and flavors, while imparting an aroma of its own
What scent is Botrytis said to impart on the grape?
One of honeysuckle
What are the special climatic conditions that set Botrytis in motion
Morning fog followed by afternoon sun
What is the most serious pest of grapevines?
The tiny louse Phylloxera
Where is phylloxera native to?
The eastern United States
During what time period did phylloxera famously spread into Europe?
The mid-1800s
Why was phylloxera not a problem in the United States?
Native vitis vinifera had developed a natural resistance to the louse, forming galls under the leaves on which phylloxera could feed
What was the first, failed attempt at protecting future vitis vinifera grapes in Europe against phylloxera?
Interbreeding Native American vines with European vines
What was the eventual solution to phylloxera in Europe?
Grafting European vines onto American rootstock
What is another soil based pest of grapevines?
The nematode
What are two ways a nematode is harmful to grapevines?
They damage the roots by feeding on them, and can also spread disease
Why are nematodes such a problem in recent times?
Due to the increased use of shallow-rooted rootstocks and drip irrigation, which don’t encourage roots to dig deep in search of water
What are two methods of preventing nematode infestations?
Using nematode-resistant rootstock, or using cover crops such as mustard as a natural biofumigant
What are several things the grower does during the winter?
Pruning excess growth off the vines, removing greenery from around the vines, and repairing equipment
What are the two general strategies of pruning called?
Cane pruning and spur pruning
What is cane pruning?
When the grower leaves only one-or-two-year-old shoots, trimmed to leave about six to ten nodes or buds
What is spur pruning?
When several canes are left, but trimmed to only a few inches, allowing only one or two nodes each
What is canopy management?
Techniques by which the position or number of shoots and grape clusters is altered
What tasks does canopy management include?
Pruning, leaf trimming, the control of yield and vine vigor, and the use of a vine training system
What is a trellis?
A network of stakes, posts, and support wires that position the wine as desired by the grower
What are four common vine training systems?
Head-training (bush training), Guyot, Cordon, Pergola
What is head training/bush training, and what type of pruning is typically employed?
It is when no trellis is used, and the vine is essentially grown like a bush or miniature tree. Spur pruning is used.
What is Guyoy?
A simple cane-pruning system in which one cane from each plant is trained along a wire facing in the same direction
What is the difference between single Guyot and double Guyot?
Single Guyot is when one cane per plant is trained along a wire in the same direction, double Guyot is when two canes are trained along the same wire in opposite directions
What is cordon training?
Cordon is the same as Guyot except spur pruned. The canes soon become as woody as the trunk.
What is pergola training?
When canes are trained vertically up a support system and then allowed to grow out horizontally with the fruit hanging down
With Guyot or cordon training systems, it is commong to see what configuration in practice?
VSP or vertical shoot positioning
What is vertical shoot positioning (VSP)?
When new growth canes are trained upwards with grape bunches positioned under the leaves in the fruiting area
What are benefits of using vertical shoot positioning?
Good air circulation and sun exposure, as well as ease of access for mechanical harvesting
Throughout much of Europe, what method of providing supplemental water to vines is prohibited?
Irrigation
In the U.S. and many other parts of the New World, sugar content is measured in degrees of what?
Brix
What are the most common tools used to measure sugar levels in grapes?
The refractometer and more old-fashioned hydrometer
What is the formula used to estimate the ethanol content of a finished dry wine relative to its sugar level?
It is estimated at about 5/9ths or about 55% Brix value
A grape harvested at 24 degrees Brix would have what ethanol level?
24 x 0.55 = 13.3%
In France, what is the unit of measurement used to estimate potential alcohol levels
Baume
What is the system for estimating ethanol content in Germany and Switzerland?
Oechsle
How is Oechsle measured?
Find the density of the grape must, subtract 1.0, and multiply by 1,000
What is the measurement of ethanol content known as in Austria?
Klosterneuberger Mostwaage (KMW)
What is organic viticulture?
Grape growing without the use of manufactured pesticides or fertilizers
What program in the United States is capable of certifying a vineyard as having employed organic practices?
The USDA’s NOP (U.S. Dept. of Agriculture’s National Organic Program)
For how many years must a vineyard be free of all chemicals prohibited by the NOP to be considered organic?
Three years.
What is IPM?
Integrated pest management
What is the goal of IPM?
To control and eliminate only those pests that are actually present and detrimental to a crop, rather than killing all insects (as some may actually be beneficial)
What is biodynamic viticulture?
Biodynamic viticulture is essentially organic viticulture with the addition of various metaphysical elements
When was biodynamic viticulture proposed and by whom?
In the early 20th century by Rudolf Steiner
How is certification as a biodynamic vineyard possible?
Through a private company called Demeter International
What is sustainable viticulture?
A method of viticulture with some goals in common with organic and biodynamic viticulture, however with out some of the strict rules of the former, with more of a long-term goal of decisions desigend to reduce overall environmental impact
