Chapter 4: Viticulture Flashcards
How much of the global output of grapevines produce wine?
Approximately 70%; remaining is table grapes, raisins or juice
Branch of agriculture that intentionally focuses on cultivation of grapevines
Viticulture
What are spurs
The buds of what will become a cane
The entire portion of the vine including the leaves and fruit is called the
Canopy
Explain how grapes protect themselves in earlier stages
By using camouflage as the grapes are green blending into the leaves and surroundings. Also the grape is very acidic (doesn’t taste good). The vine itself will grow leaves around the grapes further hiding the grapes.
The commercially viable way of grapevine propagation is called
Cloning
A genetically identical with same desirable characteristics is known as a
Clone
When a grower removes existing branches (that are not desired) and makes small incisions and inserts an unrooted cutting (from a desirable vine). This process is known as
Field Grafting
Describe the Ideal conditions for photosynthesis
Warm days, long days, clear days, minimal shading and sun facing when on slopes.
Process by which plant breaks down sugar and carbohydrates, releasing energy for use by plant.
Respiration
Process by which water evaporates through openings on the underside of leaves. Cools the plant.
Transpiration
The final metabolic process in which materials are moved from one area of a plant to another (Sugars)
Translocation
Describe the Annual Growth Cycle starting in Winter
Winter the vine is dormant and retains energy in anticipation for the spring; in the spring the first sign of awakening is called weeping. This is when vines begin to show their first greenery + sap flows upward; Bud Break is next, in this phase the vine begins to show tiny shoots called buds; Flowering takes place next, in this phase flowers appear on shoots; eventually will turn into fruit (if pollinated); Fruit-set is when the fruit begins to develop (begin small, dull green and hard); Veraison is when the fruit begins to accelerate, skins become thicker, acidity begins to decrease and sugars begin to rise. The color of the grapes also change, yellow/golden for white and darker red for black grapes. Harvest is the final and equally important step.
First critical event in the annual life cycle is ___ because the new growth is vulnerable to temperature extremes particularly colder weather.
Bud Break
Once _____ can begin, the plant can begin to create new energy through sunlight to accelerate growth.
Photosynthesis
____ typically occurs around a 1.5 - 2 months after veraison.
Harvest
Shatter or Coulure
Causes poor fruit set with many flowers failing to develop ripe grapes.
Occurs approx. 40-80 days after bud break
Flowering
Vinifera grapevines are ______, which means they do not require insects/bees for _________.
Self-pollinating and fertilization
What is millerandage and when does it occur?
During fruit set; Grapes can develop a high portion of grapes develop that do not have seeds and mixed with larger normal grapes; can be caused by bad weather.
What are the ideal regions for wine growing
Between 30 and 50 degrees latitude from the northern and southern hemisphere
What is the life cycle of a vine?
Vines can live beyond 50 years but after approximately 20 years, the vines become less vigorous produces less fruit, but often more quality grapes.
What does third leaf refer to?
Newly planted vines will typically begin producing fruit in the first annual growth but it is considered lesser quality fruit until around the third year or known as the third leaf
Climates are strongly influenced by an ocean and have high rainfalls and mild temps
Maritime Climate
A problem that causes poor fruit set
Coulure/shatter
Soil-based roundworm
Nematode
Oidium
Powdery mildew that comes from a fungal disease that can impact fruit/leaves
Peronospora
A fungal disease also known as downy mildew
A bacterial disease spread by insects such as glassy-winged sharpshooters
Pierce’s disease
A destructive louse that feeds off the roots of vinifera vines
Phylloxera
Type of vine training that does not use a trellis
Head or Bush Training
Pergola
Type of vine training that trains the vine up a tall support
Inoculation
Inoculate a wine is to add an active yeast culture to the must (juice) to activate fermentation.
Brix
Measures the concentration of sugar in degrees. Using a refractometer or hydrometer. To estimate the ethanol level in a finished dry wine …. 55% 24 degrees ( 24 * .055)
Baume
France method of determining the potential alcohol level in 100 milliliters of wine.
12 degrees Baume = 12% alcohol
Oechsle
Used in Germany and Switzerland Subtract 1.0 and multiply it by 1,000.
Density reading of 1.068 = 68 which is roughly 9% potential alcohol.
Typical Precipitation required to grow grapes
20-30 inches; though could be less; irrigation sometimes allowed usually in new world vs old world
Soils
Clay, chalk, sand, gravel, marl, loess and limestone
Vines prefer infertile soils
Soils regulate the water; ground water can be used to support regions with less rainfall; deeper root structure taps into the source; also soils play a part in keeping the ground from being overly wet … which can cause rot
