Viticulture Flashcards
How long has man domesticated the vitis vinifera?
Almost 5000 years.
Where did viticulture begin on earth?
When was the earliest evidence for grape domestication?
When was the earliest evidence of wine?
When was the earliest evidence of winemaking?
It’s uncertain where, exactly, viticulture began, but the strongest theories suggest that it arose between the Black and Caspian Seas in Transcaucasia (which includes Armenia, Georgia, and Azerbaijan), as well as in eastern Turkey, the Levant, and northern Iran.
—The earliest evidence for grape domestication, in the form of 8,000-year-old grape seeds, was found just north of Armenia at Shulaveri gorge in Georgia.
—The oldest example of wine—7,400-year-old residue on clay pots—was discovered just south of Armenia at Hajji Firuz Tepe in Iran.
—Across the Black Sea in northern Greece, findings from a settlement called Dikili Tash suggest that grapes were being crushed into wine there 6,300 years ago.
—The cave named Areni-1, in Armenia 6,100 years old, is the first place where grapes and winemaking tools have been discovered together. To put things in perspective, it’s not until a millennium or so later that wine shows up in the tombs of Egyptian pharaohs.
What begins the annual life cycle of the vine?
When does it occur?
What temperature?
Budbreak, in the spring (March/April in the northern hemisphere, September/October in southern hemisphere)
Bud will finally emerge from dormancy as the average air temperature surpasses 50F
Not counting bleeding/weeping in February.
What is weeping/bleeding?
Watery sap lost from the vine due to pruned canes in February. This is the first visible sign of the start of the new vine growth cycle.
What is the vine most susceptible to during budbreak?
Frost.
How long after budbreak does flowering occur?
6-13 weeks.
Or a month and a half to three months.
What is flowering?
How long does it last?
Between 6-13 weeks after budbreak, embryo bunches bloom into small flowers for about ten days. The self-pollinating grapevine begins the process of fertilization, which leads to fruit set.
What is fruit set?
What is it also known as?
Nouaison “NEW-a-zon” in French. Marks the transition (one week on average) from flower to grape berry. It is the result of successful pollination achieving fertilization of the ovules and the development of seeds.
-Fruit set usually hovers around 30%, as the remaining embryo berries “shatter”, falling from the cluster.
Finish this sentence. Most wine grape varieties contain up to four seeds. The more seeds there are, the ________ the berry.
larger
What percentage of flowers become berries?
About 30%.
What is shatter?
Flowers that do not set and fall from the cluster. Usually, about 70% of all embryo berriers shatter.
What are berries like through July?
Remain hard, high in acidity and low in sugar.
What is veraison and when does it begin?
“the onset of ripening” the changing of the color of the grape berries and the transition from berry growth to berry ripening. It is when grapes begin to truly ripen, as sugars are moved from the leaf system to the fruit in August/February. During veraison, the grapes soften and change colors–turning from green to red-black or yellow green–and acidity decreases.
What is cane ripening and when does it happen?
Occurs in tandem with veraison, as the stems on each shoot begin to lignify, accumulating carbohydrates to sustain the plant through the winter.
What is vendange?
Harvest. Occurs once sugar and acid have optimal balance. Begin as as early as late August, and may last through the beginning of November.
What is physiological ripeness?
Concept of ripeness comprising not only must weight and pH, but also the ripening of tannin and other phenolics, the condition of the berry and its pulp, and seed lignification—often requires longer “hang time” for the grapes on the vine.
What mean annual temperature range does a vine prefer?
Final month of ripening?
Mean annual level between 50° and 68°F, with an ideal of 57°F.
Final month of ripening needs to be 60°- 70°F.
To successfully ripen, what average summer temperature do white grapes and red grapes need?
White grapes prefer 66°F. Red grapes prefer 70°F.
What are the temperature bands of latitude for cultivation?
30° and 50° in both the northern and southern hemispheres.
What is the California Heat Summation Index?
Classifying climates solely by temperature–and therefore recommending varieties appropriate to that temperature. The scale divides climates into five Regions based on the number of degree days.
How are degree days calculated for the California Heat Summation Index?
By multiplying the days in each month of the growing season (defined as April 1 through October 31) by the mean number of degrees over 50°F for that month. The months’ totals are then added together to arrive at the heat summation.
What are the regions for the heat summation and their degree days?
Region Ia 1,500-2,000° days F (850-1,111° days C)
Region Ib 2,000-2,500° days F (1,111-1389° days C)
Region II 2,500-3,000° days F (1,389-1,667° days C)
Region III 3,000-3,500° days F (1,667-1,944° days C)
Region IV 3,500-4,000° days F (1,944-2,222° days C)
Region V 4,000-4,900° days F (2,222-2,700° days C)
What is photosynthesis?
Process through which plants use carbon dioxide, water, and light to create their own food and release oxygen into the air.
Think of plants as chefs that create their own food with these three ingredients (carbon dioxide, water, and light)
Leaves have small openings called stomata which absorb carbon dioxide in the air and release oxygen back into the atomosphere. Chloroplast, also found in the leaves, (and what gives leaves their green color) take carbon dioxide, water, and light and create sugar (glucose) and oxygen, the process of photosynthesis. The oxygen is released back into the atomosphere through the stomata, while the sugar is stored as carbohydrates.
What is the minimum amount of sunshine required to support viticulture?
1,300 hours.
-As sunshine during the growing season increases farther one moves away from the equator, vines in the cooler climates often enjoy more sunshine than vines in warmer climates.
Approximately how many inches of rain does a crop require annually?
20-30 inches.
What is vine stress?
What occurs?
When a vine receives too little rain, a condition that promotes smaller berry size and yields but will lead to interrupted ripening and complete shut down of the vine if the stress is too severe.
Name two things that happen when a vine receives too much rain?
It will dilute fruit quality and creates a friendly environment for fungal diseases.
Definition of terroir? Short and long?
“Total natural growing environment“ Jancis Robinson
-favorite definition to date
-The set of variables that characterize a particular place, encompassing everything from soil to slope to wind to the amount of sunlight a vineyard receives during the day.
Terroir is the entire system of factors that influence the development of the vine–factors that, depending on the style of viticulture and wine-making applied, may be magnified or subsumed in the resulting wine.
What is aspect?
Degree and direction of a slope.
Four techniques that are a part of canopy management?
Winter pruning
Leaf removal
Shoot positioning
Use of trellising systems.
What are clones?
identical genetic reproductions of a single vine.
What qualities are considered when selecting a clone? (6)
Disease resistance Hardiness Yield Aromatics Structure Color
What is the difference between clonal selection and selection massale?
Clonal selection is the practice of selecting a single superior plant in the vineyard and then taking cuttings from this vine for propagation.
-In mass selection, a group of superior vines are selected for propagation. With mass selection, the identity of individual vines is not maintained, which is the principal difference between the two approaches.
While the results may be less precise than those gained through clonal selection, a broader genetic diversity is maintained
Three most resistant types of rootstock used to combat Phylloxera in the late 19th century?
V. riparia, V. rupestris (St. George), and V. berlandieri
Three other reasons, besides fighting phylloxera, would one select a particular rootstock?
- to withstand other diseases and drought
- tolerance to salt and lime
- its effect on vine vigor.
How long will a newly grafted and planted vine take to produce a crop of grapes suitable for harvest?
Not till it’s third year.
What age is a grapevine considered mature?
Sixth year.
At what year does a grapevine begin to decline in yield?
20
What age are vines generally considered uneconomical?
50 years of age.
What are the two types of training methods? Describe each.
Cordon trained- Vine has at least one permanent cane that extends from the trunk, called an arm or cordon. Require a trellising system
Head trained-No permanent cordon, and the trunk ends in a knob, or head. Head trained vines may be supported by a simple stake, or not at all. Although head-trained vines may technically be trellised (i.e. the Guyot training system), head-training is commonly asserted as an alternative to trellising, synonymous with bush vines.
What is spur pruning? What climate is it typically used? Manual or Mechanical? Advantages? Disadvantages?
Spur pruning is a form of winter vine pruning whereby the canes are cut back to two-bud spurs. Normally the spurs are spaced along a cordon top and point upwards. The cane furthest away from the cordon is completely removed, the one nearest is shortened to two nodes to produce next years spur, providing sufficient quantity of fruit.
- it is common to see in warmer climate growing regions, including California, Washington, and Spain.
- Spur pruning is a more traditional training method. -
- Advantages: Spurs (the stub of a cane that contains 1-3 buds) are generally easier to prune by hand and the operation can also be mechanized easily. Certain training systems, such as goblet method, are ideal for areas prone to drought and known to produce outstanding old vine wines. Also, setting the spur spacing results in the correct shoot spacing in the canopy, which in turn leads to well-exposed leaves and fruit.
- Disadvantages: it is not particularly well suited to very vigorous vineyards, however, as excessive shade can lead to the loss of both yield (due to low bud fruitfulness) and quality.
What is cane-pruning? What climate is it typically used? Manual or Mechanical? Advantages? Disadvantages?
- Cane pruning (Guyot) is a form of winter vine pruning in which the buds are retained on longer bearers called canes, typically including six to 15 buds; typically used for vines with fewer fruitful buds at the base of canes. At pruning the two year old cane, and consequently much of this years growth, are completely removed. Of the two canes originating from the spur, the one closest to the cordon is pruned to leave a replacement two node spur, whereas the cane further away is left intact, although shortened. This is next years two year old cane.
- it is especially used in cool-climate wine regions including Burgundy, Sonoma, and Oregon.
- By limiting the vine’s lignified growth (the hard brown part) to just the trunk, the vine is less vulnerable to frost and better protected than spur pruned vines.
- usually takes longer to perform by hand than the spur pruning, as it requires manually cutting back nearly all the vine’s prior growth and correctly selecting a single cane (or two) that will be responsible for next season’s production.
- the tendency in warmer wine regions is to use spur pruning, which can be equally productive, requires less labor, and can be mechanized.
