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.
What is a shoot?
A new growth or fruiting cane (which will harden to become a woody cane) consists of a stem with leaves and tendrils which become bunches of grapes. Collectively, the shoots and leaves of a vine form its canopy.
Spur
Shortened grapevine cane. A spur is a stub formed by pruning the cane to between one and four nodes, usually two.
What is the Guyot system? What is the Guyot Double? What pruning/training system does it use?
The Guyot system requires a vertical trellis on which the canes can be suspended, and has one spur and one main two-year-old cane.
The Guyot double variant supports two main canes, extending outward from the trunk on opposite sides.
It is the most basic of cane-pruning/head-training systems.
What is the Gobelet system? What pruning/training system does it use?
An ancient technique common in the Southern Rhône and Southern Italy, wherein the vine, often unsupported, resembles a goblet, with each year’s fruiting canes extending from the spur-pruned, shortened arms atop the trunk. In Italy the Gobelet system is known as albarello; in Spain, en vaso. Australians often refer to such vines as bush vines
It is the simplest form of spur-pruning/head-training.
What is the Cordon de Royat? What pruning/training system does it use? What grape/region is it specifically used for?
The Cordon de Royat system is similar to the Guyot system, with a single spur-pruned permanent cordon extending horizontally from the trunk, rather than a two-year-old cane.
It is one of the simplest spur-pruned/cordon-trained systems and the preferred training style for Pinot Noir in Champagne.
What is Geneva Double Curtain? What pruning/training system does it use?
It is a vine-training system whereby the canopy is divided into two pendent curtains, trained downwards from high cordons or canes. The system was developed in upstate New York in the early 1960s. The foliage is trained downwards from these cordons, forming the so-called double curtains. This training system was one of the first examples of a divided canopy developed in the New World and, by reducing shade, it increases both yield and grape quality, although it offers very little vine protection. The GDC system is particularly useful for wide row spacing vineyards of high vigour. Some notable increases in yield and wine quality have resulted from use of the system.
What is the Lyre system? What kinda of pruning/training system is it?
A vine-training system whereby the canopy is divided horizontally into two curtains of upward-pointing shoots which resembles a lyre in shape (U-shape.) The lyre system improves the canopy microclimate and leads to improvement in yield and wine quality because of better leaf and fruit exposure to sunlight.
The system is being adopted in New World vineyards in particular, especially in California, and to a lesser extent in Australia, New Zealand, Chile, and Uruguay, but it has also been trialled in Beaujolais.
The lyre system is essentially an inverted geneva double curtain, with the two adjacent curtains of foliage trained upwards rather than downwards. Both systems are used to reduce the shading of dense canopies.
The lyre system is typically recommended for medium-vigour vines, whereas the GDC can harness higher vine vigour.
It can be either spur or cane pruned. It is cordon-trained (not sure about training).
What is Vertical Shoot Positioning? What kind of pruning system does it use?
—a vine-training system widely used throughout the world, in which the shoots are trained vertically upwards in summer. The shoots are held in place by foliage wires which, in turn, are attached to vineyard posts. Used for relatively low-density plantings.
—may be used for either cane-pruned or spur-pruned vines
What is the Tendone System?
Two other names?
Also known as pergola in Italy and enforcado in Portugal, is an alternative training system in which the vines are trained upward and overhead along wooden frames or trees, enabling workers to pass underneath.
Tendone vines may be either spur- or cane-pruned.
What are the four main vine disease categories?
Fungal
Viral
Bacterial
Phytoplasma
Fungal diseases.
How do they manifest?
What climates are they found?
How are they spread?
What are two types of fungal disease?
How are they controlled?
Most common types?
- Fungal diseases manifest as mildew or mold and attack either the root system or the canopy of the grapevine.
- Signs of infection by fungi are freckles, necrosis, cover moldy, rotting and withering.
- Typically associated with warm and damp climates.
- Fungal spores are spread by wind and rain.
- Some of the most worrisome fungal diseases include powdery and downy mildew
- Fungal diseases can be successfully controlled—if not wholly eradicated—through fungicide sprays and other applications
- downy mildew, powdery mildew, gray mold, dead arm, and black rot.
Bacterial disease
How do they manifest?
How are they spread?
How are they controlled?
Most common types?
—Bacteria are microscopic one-celled organisms that grow rapidly.
—while most bacteria in the environment are beneficial, several are able to cause leaf spots, stem rots, root rots, galls wilts, blights, and cankers.
—most common signs of bacterial infections are inflammation of the tissues and formation of cancer wounds.
—enters vines through wounds, natural openings in the vine or direct penetration, usually in the leaf or fruit but sometimes in roots and stems.
—once inside the grapevine, bacteria begin to reproduce by simple cell division and doesn’t produce spores or fruiting bodies like fungi.
—spread primarily by wind-driven rain, driving or walking through a vineyard wet from dew; moved from soil/debris through workers.
—bacteria, like fungi, rely on their host plant for food. In the absence of a host plant, a bacterial population may decline rapidly. Control is difficult depending on the specific disease; many owners have abandoned vineyards.
—insects spread some bacterial diseases such as Pierce’s disease (most important); quarantine authorities around the world anxious to stop spreading from America. In parts of North and Central America (southern California, Florida, and eastern Texas, for instance), viticulture can be rendered commercially impossible by presence of Pierce’s disease.
—Pierce’s disease, Crown gall, Bacterial Blight, and Happy disease
Viral Disease
How do they manifest?
What climates are they found?
How are they spread?
How are they controlled?
Most common types?
—viruses are microscopic pathogens living inside the living cells.
—after entering into the vines they spread into all underground and above ground plant parts
—infected vines experience a shortened lifespan, reduced yields and a changed quality of fruit.
—often less immediately destructive than bacterial diseases, but there is no known cures for many.
—affects changes in the shape, size and color of lamina and changes on the vine shoot and clusters.
—spread through grafting or transmitted by insects
—viral diseases are controlled through removal and appropriate selection for propagation.
—Feanleaf virus and Leafroll
Phytoplasma diseases
How do they manifest?
How are they spread?
First recorded?
What climates are they found?
How are they controlled?
Most common types?
- caused by phytoplasmas, pathogens similar to bacteria (they are in fact obligate bacterial parasites), yet they are symptomatically similar to viral diseases and, like viruses, must be spread through an insect vector or rootstock grafting.
- also known as grapevine yellows, were first recorded in Europe in the mid-1990s, and may cause widespread difficulties in the 21st century.
- first sign of grapevine yellows can be delayed budbreak/slow shoot. Later, shoots stop growing while leaves yellow and curl downwards. Later in the season, shoots droop as though made of rubber.
- when affected early in the season, bunches fall off. Otherwise, the berries shrivel and taste bitter.
- symptoms seem to vary from year to year, and crop levels fluctuate.
- during epidemics, as for example in the Prosecco region in northern Italy in 1995, yields of some vineyards dropped to one-tenth of a normal crop. The Australian experience is that vineyards with well-established infections yield at about half the rate of healthy vineyards.
- recent years, climate change has been implicated, as the insect vectors spreading the disease migrate.
- there is no known control.
- the disease occurs sporadically in epidemics, and varieties vary in their sensitivity to it.
- Flavescence dorée (FD), Bois Noir (BN), Grape leaf rust mite and Grapevine yellows (GY)
What is phylloxera?
When and where was it first found?
How do they manifest?
How are they spread?
How are they controlled?
—Not a disease, but an infestation of a small yellow root-feeding aphid. It attacks only grapevines (leaves, tendrils, and roots), and kills vines by attacking their roots. It was first noted in 1863, just as France was recovering from powdery mildew, first found in 1847.
—It is native to the Eastern United States, but it quickly spread through Europe from cuttings imported to the Southern Rhone Valley. Most of the world’s Vitis vinifera vines are today grafted onto native American vine rootstocks, which are naturally resistant to the phylloxera root louse.
***Other insects-mealy bugs, nematodes, and glassy-winged sharpshooters—act as carriers, or vectors, of disease, and their appearance in the vineyard may be a harbinger of a coming infection.
What are certain aspects sustainability may govern? (7)
water usage energy efficiency pest and erosion control the planting of cover crops the degree of mechanization planting decisions labor practices
What is Integrated Pest Management?
IPM is considered a sustainable approach to weed, insect, and disease problems that tolerates the targeted application of some synthetic products, but limits their use overall.
It has the potential to increase economic returns for the grower and improve environmental and human safety by reducing, limiting or even eliminating the use of agrochemicals.
IPM is often seen as a first step towards organic or even biodynamic viticulture.
What is VINEA?
Winegrowers’ sustainable trust. A voluntary group of Walla Walla Valley winegrowers who promote a holistic , socially- and environmentally-responsible methodology. Promotes sustainable wine growing.
What is LIVE?
LIVE (Low Input Viticulture and Enology, a third-party certifying system for sustainablity in Oregon. It based on a Swiss model known as Vintura.
What is biodynamics? Who introduced it and when? Who is the leader of biodynamics today?
Takes the concepts of organic and sustainable farming and combines them with mystical sensibility of observing the rhythms and forces of the Earth for a successful ecosystem. The farm, in concert with the cosmic periphery, becomes a whole organism generating its own fertility as governed by the cycle of seasons and lunar activity.
-Introduced by the Austrian Rudolf Steiner in 1924 and today personified by Nicolas Joly of the Loire.
Who certifies biodynamics?
The Demeter Biodynamic Trade Association certifies biodynamic farms and vineyards internationally.
What is whip graft/whip and tongue graft?
Whip graft (also seen it as splice graft) is the form used in grafting which simply involves an angled slice across the scion stem and a similarly angled cut of the stock, with the two cuts then matched and the graft tied tightly with grafting tape. Whip-and-tongue is the same except that another cut is made to raise ‘tongues’ of stem tissue that dovetail with each other and improve the strength of the graft. Whip-and-tongue uses the natural compression due to wood elasticity. Whip graft has no compression.
What is an omega cut?
The most common (European) cut used for grafting, where the two pieces come together in an “omega shaped” epiglottis.
What is the difference between coulure and millerandage?
What grapes are susceptible to coulure? millerandage?
Coulure is a form of poor fruit set in the grapevine. Excessive shedding of ovaries and young berries results in relatively few berries per bunch, either during or soon after flowering, causing them to drop off.
Susceptible to Coulure, Grenache, Malbec, Cabernet Sauvignon, and Merlot
Millerandage is another form of poor fruit set, in which there is an excessively high proportion of different-sized berries in the same bunch, i.e. excessively high proportion of seedless berries and ‘live green ovaries’ (LGOs) relative to seeded berries. Seedless berries are sometimes known as chicken berries (normal seeded berries are the hens). Whereas seedless berries will mature normally, LGOs do not and remain firm and green. They have been known as shot berries in the past, but this nomenclature is inappropriate because they do not fit the definition of a berry. Some grapes such as Pinot noir or the Mendoza clone of Chardonnay, wine quality could be improved due to the reduced overall berry size and higher skin to juice ratio.
Susceptible to Millerandage: Merlot, Sangiovese, Zinfandel and Gewürztraminer.
What is Powdery Mildew?
Also known as? Type of disease? What happens when infected? How is it spread? First recorded? How is it controlled?
—also known as oidium, it is a fungal disease native to North America, has spread worldwide and thrives even in humid yet dry conditions—rainfall actually a detriment to survival of its spores. The disease develops and spreads most rapidly in warm weather, 20 to 27 °C (68–80 °F).
—Unlike other fungal diseases, this one is little affected by humidity, making climate conditions which favor it different from those which favor many others.
—affects all green parts of the plant, marking grapes, leaves, and shoots with its dusty white mildew growth.
—prefers densely shaded canopies and overcast weather, and greatly inhibits bunch development and ripening.
—If infected prior to flowering, yields will be reduced; if infected after fruit set, berries struggle to achieve veraison and reach full size.
—Spores are spread by wind and, with favorable conditions, new infections rapidly occur.
—Powdery mildew, first recorded in England in 1847, spread quickly throughout the Vitis vinifera vineyards of Europe
—was controlled by applications of sulfur and other fungicides.
What is Downy Mildew?
Also known as? Type of disease? What happens when infected? How is it spread? First recorded? How is it controlled?
—also known as Peronospera, it is a fungal disease that emigrated to Europe on North American vine cuttings,
—attacks the green portions of the vine, causing leaves to drop off the vine and limiting the vine’s ability to photosynthesize.
—the infection is first visible as an oil spot on vine leaves.
—as spores germinate a white, cottony growth develops on the underside of the leaves.
—the fungus survives the winter on fallen leaves in the soil, and its spores reach the vine again with the help of rain splatter in the spring.
—Downy Mildew spread rampantly through France and the rest of Europe in the early 1880s.
—Arid regions prohibit its growth.
—the blue-staining Bordeaux Mixture, a spray of copper sulfate, water and lime, was developed by 1885 to prevent outbreaks of downy mildew.
What is Eutypa Dieback?
Also known as? Type of disease? Where is it common? What happens when infected? How is it controlled? Similar disease?
—also called dead arm, it is a fungal disease caused by the Eutypa lata fungus.
—also a trunk disease (like esca or black dead arm (BDA)Fesca; dieback is a condition in which a tree or shrub begins to die from the tip of its leaves or roots backward
—spores are carried by rain and enter the vine through pruning wounds.
—common in Mediterranean climates
—Symptoms are characterized by dieback; death of spurs, canes, cordons, trunks, and eventual vine death due to canker formation in the vascular tissue.
—infected vines experience stunted shoot growth as the fungus releases toxins, and eventually an infected cane may die—the dead arm.
—has a drastic effect on yield, but does not devalue the quality of the crop. In fact, Australia’s d’Arenberg ascribes a beneficial effect on quality to the dead arm, and markets its icon Shiraz under the disease’s nickname.
—the disease is difficult to control as it affects a wide number of plants.
—separate fungus, Phomopsis viticola, manifests as a similar disease.
When do yields (typically) start to decline in a vine?
25-30 years
What is Esca?
Also known as? Type of disease? What happens when infected? How does it spread? How is it controlled?
- also known as Black Measles, it is one of the earliest known fungal grapevine diseases
- also a trunk disease like Eutypa dieback or black dead arm (BDA)
- Esca thrives in warmer climates but exists worldwide.
- unlike other fungal diseases, Esca is the result of a complex of fungi, rather than a single organism.
- on young vines, the disease will weaken growth, affect berry development and discolor leaves; in hot weather an affected young vine may suddenly die.
- in older vines, the disease affects the wood, causing the interior of the trunk and arms to soften and rot from the inside. Mature, Esca-infected vines will rarely live past 30 years of age.
- the disease is exacerbated by rainfall and can be spread by wind or on the pruning shears of careless vineyard workers.
- there is no known control or cure.
What is Black Rot?
Type of disease?
First discovered?
What happens when infected?
How it it controlled?
- it is fungal disease is caused by the Guignardia bidwelli
- native to North America it spread to Europe with the importation of phylloxera-resistant rootstocks in the late 1800s.
- originating as a black spot on the vine’s shoots, leaves, and berries.
- although yield reductions can be disastrous if unchecked (up to 80%), the disease can be controlled through fungicide sprays.
What is Bunch Rot?
Type of disease? Malevolent form? What happens when infected? Benevolent form? What does bunch rot require to germinate?
- a grouping of similar diseases caused by a number of fungi species.
- reduces crop yields and may adversely affect the character of the wine, imbuing it with moldy off-flavors.
- in its malevolent form as grey rot, the fungus will break down the skin of berries and allow other yeasts and bacteria to rot the grapes.
- it spreads quickly throughout vineyards.
- if the fungus invades healthy white grapes under favorable conditions, it will instead result in the noble rot, a precondition for some of the world’s greatest sweet wines.
- Botrytis bunch rot requires warm weather and humidity of at least 90% to germinate.
What is Pierce’s Disease?
Type of disease? What is the bacteria? How is it transmitted? What happens when infected? Where is it found? How it it controlled?
- it is a bacterial disease caused by Xylella fastidiosa
- most commonly transmitted by the glassy-winged sharpshooter—a leafhopping insect found near citrus orchards and oleander plants
- it renders vines incapable of producing chlorophyll and killing it within one to five years.
- it is common in the southern United States and Mexico but is steadily moving northward in California, with sightings of the glassy-winged sharpshooter and outbreaks of the disease provoking major alarm in both Sonoma and Napa counties.
- There is neither a cure nor a chemical control for the disease, and authorities in other countries are maintaining strict quarantines to prevent its incursion.
What is Crown Gall?
Also known as? Type of disease? How it it infected? What happens when infected? Where does it thrive?
- also known as Black Knot, it is a bacterial disease found in a wide variety of plant species
- it is spread through the propagation of bacteria-infected budwood.
- a vine develops tumors (galls) on its trunk, which girdle and essentially strangle the vine, withering or killing outright the portions of the vine above.
- thrives in colder climates
- during winter freezes, when the vine’s trunk may be ruptured, the bacteria invade the outer trunk, rapidly multiplying and stirring up the onset of disease.
What is Bacterial Blight?
Type of disease?
What happens when infected?
How is it spread?
How can it be controlled?
It is a bacterial disease caused by Xanthomonas ampelina
-often kills young grapevine shoots. They develop dark brown streaks in early spring, and eventually wither and die.
Spread by rain and compromised pruning tools
-controlled by hot water treatments and copper sprays, such as the Bordeaux Mixture.
What is Leafroll?
Type of disease? How much world grape production loss? Particular problem where? Signs of infection? What happens when infected? How is it spread? How can it be controlled?
-viral disease caused by a complex of at least nine different viruses
-may be responsible for as much as 60% of the world’s grape production losses.
-has been a particular problem in South Africa
-vines display radiant shades of red and gold in the autumn, such beautiful colors, combined with a characteristic downward curling of the leaves, signal the virus
-reduced yields and delayed ripening
-spreads through propagation of infected vines or by an insect vector like the mealy bug
it is currently incurable but it will not kill the vine; thus, infected vines are not always removed.
What is Fanleaf Degeneration?
Type of disease?
What does it look like
What happens when infected?
How can it be controlled?
It is a nepovirus (viral disease spread by soil nematodes feeding on infected roots)
- one of the oldest known viral diseases affecting vines
- deforms shoot growth, and leads to poor fruit set and shot (seedless) berries, severely curtailing yields.
- productive lifespan of the vine and its winter durability are diminished
- there is no control for an infected vineyard and it must be removed. The virus particle can survive in root pieces for over six years. Nematode populations can be reduced by fumigation.
What is Flavescence Dorée?
Type of disease? First appeared? What spreads the disease? Signs of infection? What happens when infected? How can it be controlled?
- a phytoplasma disease of the vine (a form of grapevine yellows)
- it has the potential to threaten many of the world’s vineyards and is becoming more widespread due to climate change.
- first appeared in Armagnac in 1949.
- leafhopper insects and propagation of infected vines spread the disease
- will initially delay budbreak and slow shoot growth, eventually causing bunches to fall off the vine and berries to shrivel. The disease will discolor leaves, cause pustules and cracks to form, and may kill young vines.
- No cure exists, although insecticides may be used to control leafhopper insect populations and retard its spread.
What is the difference between Flavescence Dorée and Pierce’s disease?
Flavescence dorée is a bacterial disease caused by a class of plant parasites called phytoplasma. The bacteria survives in leaf-hopper insects and from there infects vines, essentially eating plant cell wall material. Pierce’s disease, on the other hand, is a bacterial disease that causes the vine to stop taking in water.
How long is a typical growing season?
150-190
Why are organic practices more difficult in cooler maritime climates difficult?
Winters may not always be cold enough for the vines to fall dormant, and organic viticulture may be difficult because pests and diseases are not always killed off in the winter.
What is a cap?
A tiny green cover on an individual, unopened grape flower in a cluster on the vine. The cap loosens and then falls off, exposing the pinhead-size, female ovary and releasing the yellow, pollinating (male) anthers of an individual grape flower. When this cap falls off, allowing the yellow anthers to open, the flower is said to be in bloom.
Why would a vine be planted high (“vignes hautes”), low (“vignes basses”), wide apart, or close together?
High Vines: Tall vine trunks lift the grapes higher above the ground to increase airflow and increase sun exposure, which reduces the probability of fungal infections. Also reduces the risk of frost. This training method is more common in cooler climates with high moisture. Requires thicker and more expensive supports.
Low Vines: Short vine trunks reduce a vine’s exposure to the sun and moderate temperature variation. This is more common in hotter growing regions.
Widely Spaced Vines: In very dry regions, spacing vines farther apart increases their ability to access nutrients from the soil. In moist or irrigated areas, it also increases the vines production (which simultaneously reduces quality).
Closely Spaced Vines: Closely spacing vines is a way to limit each vine’s vigor, limiting production and improving quality.
What is the traditional vine density of Bordeaux, Burgundy, and Champagne? How are they traditionally spaced?
What is the traditional vine density of New World vineyards? How are they traditionally spaced?
Bordeaux, Burgundy, Champagne
- 10,000 plants per ha (4,050 per acre) (and sometimes more)
- vines spaced typically 1 m apart both within and between the rows.
New World
- 1,080 vines per ha
- a spacing of 2.5 m/8 ft between vines along the row and 3.7 m/12 ft between rows is quite common.
What parts of the world would you find the lowest vine densities?
Probably the most widely spaced vineyards of the world are those of the Vinho Verde region in Portugal, La Mancha in Spain, and some parts of Chile, Japan, and Italy, with spacings as wide as 4 m by 4 m, or just 625 vines per ha.
What are arguments for high vine/low vine density?
High Vine Density:
Pros:
-some argue high vine densities lead to improved wine quality
-The yield of densely planted vineyards is higher, especially in the first years of the vineyard’s life and with vines planted on low soil potential.
-narrow spacings are appropriate to vineyards with moderate vigor, which is a feature of the low soil potential of these vineyards.
-suited to vineyards of low soil fertility, or more correctly of low soil’s potential.
-theory that dense planting causes root competition and substantial devigoration, but this has infrequently, if ever, been demonstrated.
Cons:
-Increased cost of establising and running high-density vineyards
-Depending on spacing can be difficult to harvest.
-Costs are higher for trellis systems, drip irrigation, and time taken to plough/spray
Low Vine Density Pros: -Allows for easier harvest/labor Cons: -Less plants=less yields
What is crop thinning?
What else is it known as?
When it is carried out?
Where did it begin?
Viticultural practice which, it is claimed, improves wine quality by encouraging fruit ripening. It is know as eclaircissage or vendage verte (green harvest) in French. Some bunches are removed from the vine and those remaining should in theory ripen more quickly with the benefit of improved leaf to fruit ratio.
- usually carried out by hand, and is therefore expensive
- usually carried out during veraison, when it is obvious which bunches are slow to ripen; later bunch removal has more impact on yield, and earlier removal on fruit ripening.
- technique became common in the early 1990s among the better producers of Bordeaux, where it had been practiced at Petrus since 1973
What is aspersion?
The process of using water sprinklers to protect budding vines from late-spring frosts.
What is Fouloir?
French term for the crush
Difference between mesoclimate and microclimate?
Mesoclimate: what happens in a region on a smaller scale.
Microclimate: what exists within a few rows of a vineyard.
What is Buttage?
French term for adding mounds of earth to the base of a newly grafted vine to cover the graft union between the rootstock and scion to protect from frost damage.
Original biodynamic preparations, outlined by Rudolf Steiner, are numbered 500-508. What are each of them?
Numbers 500 and 501 are used as foliar sprays to stimulate frowth. Numbers 502-507 are used for compost inoculation. Number 508 is used as a foliar spray to suppress fungal disease.
500: Cow manure
501: Horn-Silica
502: Yarrow Blossoms
503: Chamomile Blossoms
504: Stinging Nettle
505: Oak Bark
506: Dandelion Flowers
507: Valerian Flowers
508: Horsetail Plant
What is #500 in the biodynamic preparations?
Benefits?
Cow manure- placed in cow horn and buried for winter; changes the composition of the manure which is then mixed with water and sprayed at a rate of 60 g/ha in 34 liters of water. Usually first preparation used in transitioning to organic/biodynamic viticulture
Describe #501 in the biodynamic preparations?
Benefits?
Horn-Silica- Ground quartz is mixed with rainwater and packed in a cow horn. The horn is buried in the spring and dug up in autumn. Mixture is then sprayed on young crops and before fruit maturation at a rate of 1 gram to 13 liters of water (per acre). Enhances photosynthesis of the leaf and sugar levels at harvest
Describe #502 in the biodynamic preparations? Benefits?
Yarrow Blossoms: The flower heads are placed in a stag’s bladder. Applied to compost. Increases Potassium and Sulfur content.
Describe #503 in the biodynamic preparations? Benefits?
Chamomile Blossoms: The blossoms are stuffed into cow’s intestines, then buried. Increases Calcium and Nitrogen content.
Describe #504 in the biodynamic preparations?
Benefits?
Stinging Nettle: Applied to compost. A tea from stinging nettle is sometimes sprayed on low vigor vines. Increases Iron and Magnesium content.
Describe #505 in the biodynamic preparations?
Benefits?
Oak Bark: The flower heads are placed in a stag’s bladder. Applied to compost. Increases Calcium content.
Describe #506 in the biodynamic preparations?
Benefits?
Dandelion Flowers: Flowers are placed in cow mesentery. Applied to compost. Increases Silica content.
Describe #507 in the biodynamic preparations?
Benefits?
Valerian Flowers: The juice from the flowers is applied to compost. Increases Phosphorous content.
Describe #508 in the biodynamic preparations?
Benefits?
Horsetail Plant: A tea is prepared from the plant. The tea is high in Silica content and is used to cope with fungal diseases.
What type of rootstock, thought to be resistant to phylloxera, destroyed the vineyards of California in the 1980s?
AXR1 — variety of rootstock widely used in northern California until, in the late 1980s, it became fatally obvious that it was not resistant to phylloxera, something French vignerons had known for many decades. For more information, see rootstock.
What is must weight?
measure of the amount of sugar in grape juice (must), and hence indicates the amount of alcohol that could be produced if it is all fermented to alcohol, rather than left as residual sugar. Physically correct term would be must density.
Germany and Switzerland- degrees Oechsle (°Oe)
Italy, France and Canada- degrees Brix
United States- specific gravity
Austria- Klosterneuburger Mostwaage (KMW) scale
Czech Republic and Slovakia- degrees Normalizovaný moštoměr (°NM).
What is passerillage?
The vine shuts down as sap recededs to the root and grapes are allowed to hang on the vine until they start to dehydrate. This process concentrates the sugars in the juice and changes the flavours within it.
What is engustment?
(latin: gustis or taste) The stage of ripening when aroma and flavor become apparent, as the berries build up sugar and soften.
