Viticulture

Viticulture

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Viticulture is the science
Science
Science is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe...

, production and study of grape
Grape
A grape is a non-climacteric fruit, specifically a berry, that grows on the perennial and deciduous woody vines of the genus Vitis. Grapes can be eaten raw or they can be used for making jam, juice, jelly, vinegar, wine, grape seed extracts, raisins, molasses and grape seed oil. Grapes are also...

s which deals with the series of events that occur in the vineyard
Vineyard
A vineyard is a plantation of grape-bearing vines, grown mainly for winemaking, but also raisins, table grapes and non-alcoholic grape juice...

. When the grapes are used for winemaking
Winemaking
Winemaking, or vinification, is the production of wine, starting with selection of the grapes or other produce and ending with bottling the finished wine. Although most wine is made from grapes, it may also be made from other fruit or non-toxic plant material...

, it is also known as viniculture. It is one branch of the science of horticulture
Horticulture
Horticulture is the industry and science of plant cultivation including the process of preparing soil for the planting of seeds, tubers, or cuttings. Horticulturists work and conduct research in the disciplines of plant propagation and cultivation, crop production, plant breeding and genetic...

.

While the native territory of Vitis vinifera
Vitis vinifera
Vitis vinifera is a species of Vitis, native to the Mediterranean region, central Europe, and southwestern Asia, from Morocco and Portugal north to southern Germany and east to northern Iran....

, the common grape vine, is a band of area from Western Europe
Western Europe
Western Europe is a loose term for the collection of countries in the western most region of the European continents, though this definition is context-dependent and carries cultural and political connotations. One definition describes Western Europe as a geographic entity—the region lying in the...

 to the Persian
Iran
Iran , officially the Islamic Republic of Iran , is a country in Southern and Western Asia. The name "Iran" has been in use natively since the Sassanian era and came into use internationally in 1935, before which the country was known to the Western world as Persia...

 shores of the Caspian Sea
Caspian Sea
The Caspian Sea is the largest enclosed body of water on Earth by area, variously classed as the world's largest lake or a full-fledged sea. The sea has a surface area of and a volume of...

, the vine has demonstrated high levels of adaptability
Adaptability
Adaptability is a feature of a system or of a process. This word has been put to use as a specialised term in different disciplines and in business operations. Word definitions of adaptability as a specialised term differ little from dictionary definitions...

 and will sometimes mutate to accommodate a new environment after its introduction. Because of this, viticulture can be found on every continent except Antarctica.

Duties of the viticulturist include: monitoring and controlling pests and diseases, fertilizing
Fertilizer
Fertilizer is any organic or inorganic material of natural or synthetic origin that is added to a soil to supply one or more plant nutrients essential to the growth of plants. A recent assessment found that about 40 to 60% of crop yields are attributable to commercial fertilizer use...

, irrigation, canopy management, monitoring fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...

 development and characteristics
Typicity
Typicity is a term in wine tasting used to describe the degree to which a wine reflects its varietal origins, and thus demonstrate the signature characteristics of the grape from which it was produced, i.e., how much a Merlot wine “tastes like a Merlot”...

, deciding when to harvest
Harvest (wine)
The harvesting of wine grapes is one of the most crucial steps in the process of winemaking. The time of harvest is determined primarily by the ripeness of the grape as measured by sugar, acid and tannin levels with winemakers basing their decision to pick based on the style of wine they wish to...

 and vine pruning
Pruning
Pruning is a horticultural practice involving the selective removal of parts of a plant, such as branches, buds, or roots. Reasons to prune plants include deadwood removal, shaping , improving or maintaining health, reducing risk from falling branches, preparing nursery specimens for...

 during the winter months. Viticulturists are often intimately involved with winemakers, because vineyard management and the resulting grape characteristics provide the basis from which winemaking can begin.

History


The history of viticulture is closely related to the history of wine
History of wine
The history of wine spans thousands of years and is closely intertwined with the history of agriculture, cuisine, civilization and humanity itself...

 with evidence of man cultivating wild grapes to make wine dating as far back as the Neolithic
Neolithic
The Neolithic Age, Era, or Period, or New Stone Age, was a period in the development of human technology, beginning about 9500 BC in some parts of the Middle East, and later in other parts of the world. It is traditionally considered as the last part of the Stone Age...

 period. There is evidence that some of the earliest domestication
Domestication
Domestication or taming is the process whereby a population of animals or plants, through a process of selection, becomes accustomed to human provision and control. In the Convention on Biological Diversity a domesticated species is defined as a 'species in which the evolutionary process has been...

 of Vitis vinifera occurred in the area of the modern day country Georgia
Georgia (country)
Georgia is a sovereign state in the Caucasus region of Eurasia. Located at the crossroads of Western Asia and Eastern Europe, it is bounded to the west by the Black Sea, to the north by Russia, to the southwest by Turkey, to the south by Armenia, and to the southeast by Azerbaijan. The capital of...

. There is also evidence of grape domestication occurring Near East
Near East
The Near East is a geographical term that covers different countries for geographers, archeologists, and historians, on the one hand, and for political scientists, economists, and journalists, on the other...

 in the Early Bronze Age
Bronze Age
The Bronze Age is a period characterized by the use of copper and its alloy bronze as the chief hard materials in the manufacture of some implements and weapons. Chronologically, it stands between the Stone Age and Iron Age...

 around 3200 BC.

The earliest act of cultivation appears to have been the favoring of Hermaphroditic members of the Vitis vinifera species over the barren male vines and the female vines which were dependent on having a nearby male to pollinate. With the ability to pollinate itself, over time the hermaphroditic vines were able to sire offspring
Offspring
In biology, offspring is the product of reproduction, of a new organism produced by one or more parents.Collective offspring may be known as a brood or progeny in a more general way...

 that was consistently hermaphroditic itself.

At the end of the 5th century BC, the Greek
Greeks
The Greeks, also known as the Hellenes , are a nation and ethnic group native to Greece, Cyprus and neighboring regions. They also form a significant diaspora, with Greek communities established around the world....

 historian Thucydides
Thucydides
Thucydides was a Greek historian and author from Alimos. His History of the Peloponnesian War recounts the 5th century BC war between Sparta and Athens to the year 411 BC...

 wrote:

The time period that Thucydides was most likely referencing was the time between 3000 BC and 2000 BC when viticulture emerged in force in the areas of Asia Minor
Asia Minor
Asia Minor is a geographical location at the westernmost protrusion of Asia, also called Anatolia, and corresponds to the western two thirds of the Asian part of Turkey...

, Crete
Crete
Crete is the largest and most populous of the Greek islands, the fifth largest island in the Mediterranean Sea, and one of the thirteen administrative regions of Greece. It forms a significant part of the economy and cultural heritage of Greece while retaining its own local cultural traits...

, Greece
Ancient Greece
Ancient Greece is a civilization belonging to a period of Greek history that lasted from the Archaic period of the 8th to 6th centuries BC to the end of antiquity. Immediately following this period was the beginning of the Early Middle Ages and the Byzantine era. Included in Ancient Greece is the...

 and the Cyclades
Cyclades
The Cyclades is a Greek island group in the Aegean Sea, south-east of the mainland of Greece; and a former administrative prefecture of Greece. They are one of the island groups which constitute the Aegean archipelago. The name refers to the islands around the sacred island of Delos...

 of the Aegean Sea
Aegean Sea
The Aegean Sea[p] is an elongated embayment of the Mediterranean Sea located between the southern Balkan and Anatolian peninsulas, i.e., between the mainlands of Greece and Turkey. In the north, it is connected to the Marmara Sea and Black Sea by the Dardanelles and Bosporus...

. It was during this period that grape cultivation moved from being just an aspect of local consumption
Staple food
A staple food is one that is eaten regularly and in such quantities that it constitutes a dominant portion of a diet, and that supplies a high proportion of energy and nutrient needs. Most people live on a diet based on one or more staples...

 to an important component of local economies and trade
Trade
Trade is the transfer of ownership of goods and services from one person or entity to another. Trade is sometimes loosely called commerce or financial transaction or barter. A network that allows trade is called a market. The original form of trade was barter, the direct exchange of goods and...

.

Roman viticulture


Between 1200 BC to 900 BC the Phoenicia
Phoenicia
Phoenicia , was an ancient civilization in Canaan which covered most of the western, coastal part of the Fertile Crescent. Several major Phoenician cities were built on the coastline of the Mediterranean. It was an enterprising maritime trading culture that spread across the Mediterranean from 1550...

ns developed viticulture practices that were later utilized in Carthage
Carthage
Carthage , implying it was a 'new Tyre') is a major urban centre that has existed for nearly 3,000 years on the Gulf of Tunis, developing from a Phoenician colony of the 1st millennium BC...

. Around 500 BC, the Carthaginian writer Mago
Mago (agricultural writer)
Mago was a Carthaginian writer, author of an agricultural manual in Punic which was a record of the farming knowledge of Carthage. The Punic text has been lost, but some fragments of Greek and Latin translations survive....

 recorded these practices in a 28 volume work that was one of the few artifacts to survive the Roman
Ancient Rome
Ancient Rome was a thriving civilization that grew on the Italian Peninsula as early as the 8th century BC. Located along the Mediterranean Sea and centered on the city of Rome, it expanded to one of the largest empires in the ancient world....

 destruction of Carthage during the Third Punic War
Third Punic War
The Third Punic War was the third and last of the Punic Wars fought between the former Phoenician colony of Carthage, and the Roman Republic...

. The Roman statesman Cato the Elder
Cato the Elder
Marcus Porcius Cato was a Roman statesman, commonly referred to as Censorius , Sapiens , Priscus , or Major, Cato the Elder, or Cato the Censor, to distinguish him from his great-grandson, Cato the Younger.He came of an ancient Plebeian family who all were noted for some...

 was influenced by these texts and around 160 BC wrote De Agri Cultura
De Agri Cultura
De Agri Cultura , written by Cato the Elder, is the oldest surviving work of Latin prose. Alexander Hugh McDonald, in his article for the Oxford Classical Dictionary, dated this essay's composition to about 160 BC and noted that "for all of its lack of form, its details of old custom and...

which expounded on Roman viticulture and agriculture. The Roman writer Columella
Columella
Lucius Junius Moderatus Columella is the most important writer on agriculture of the Roman empire. Little is known of his life. He was probably born in Gades , possibly of Roman parents. After a career in the army , he took up farming...

 produced the most detailed work on Roman viticulture with his twelve volume AD 65 text De Re Rustica. Columella work is one of the earliest to detail trellis
Trellis (agriculture)
A trellis is an architectural structure, usually made from interwoven pieces of wood, bamboo or metal that is often made to support climbing plants...

 systems for getting vines off the ground. Columella advocated the use of stakes versus the previously accepted practice of training the vines to grow up along tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...

 trunks. The benefits of using stakes over trees was largely to minimize the dangers associated with climbing trees, which was necessary to prune the dense foliage to give the vines sunlight and later to harvest.

Roman expansion across Western Europe also brought Roman viticulture to the areas that would be home to some of the world's most well known wine-growing regions; the Spanish Rioja
La Rioja (Spain)
La Rioja is an autonomous community and a province of northern Spain. Its capital is Logroño. Other cities and towns in the province include Calahorra, Arnedo, Alfaro, Haro, Santo Domingo de la Calzada, and Nájera.-History:...

, the German Mosel, and the French Bordeaux
Bordeaux
Bordeaux is a port city on the Garonne River in the Gironde department in southwestern France.The Bordeaux-Arcachon-Libourne metropolitan area, has a population of 1,010,000 and constitutes the sixth-largest urban area in France. It is the capital of the Aquitaine region, as well as the prefecture...

, Burgundy and Rhône. Roman viticulturists were among the first to identify steep hillsides as one of the more ideal locations to plant vines because cool air runs downhill and gathers at the bottom of valleys. While some cool air is beneficial, too much can rob the vine of the heat it needs for photosynthesis
Photosynthesis
Photosynthesis is a chemical process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight. Photosynthesis occurs in plants, algae, and many species of bacteria, but not in archaea. Photosynthetic organisms are called photoautotrophs, since they can...

 and in the wintertime increase the hazard for frost
Frost
Frost is the solid deposition of water vapor from saturated air. It is formed when solid surfaces are cooled to below the dew point of the adjacent air as well as below the freezing point of water. Frost crystals' size differ depending on time and water vapour available. Frost is also usually...

.

Medieval viticulture


In the Middle Ages
Middle Ages
The Middle Ages is a periodization of European history from the 5th century to the 15th century. The Middle Ages follows the fall of the Western Roman Empire in 476 and precedes the Early Modern Era. It is the middle period of a three-period division of Western history: Classic, Medieval and Modern...

, Catholic monk
Monk
A monk is a person who practices religious asceticism, living either alone or with any number of monks, while always maintaining some degree of physical separation from those not sharing the same purpose...

s (particularly the Cistercians) were the most prominent viticulturists of the time period. Around this time, an early system of Metayage
Metayage
The Metayage system is the cultivation of land for a proprietor by one who receives a proportion of the produce, as a kind of sharecropping.-Origin and function:...

emerged in France with laborers (Prendeur
Prendeur
A prendeur, a French term, is a labourer working as part of an early Middle Age share cropping system known as complant, a precursor to the métayage system. Under this system, the prendeur would cultivate land owned by a bailleur. In exchange for using the bailleur's soil, the prendeur promised a...

) working the vineyards under contractual agreements with the landowners (Bailleur
Bailleur
A bailleur, a French term, is a land owner who outsourced uncultivated parcels of land as part of an early Middle Age share cropping system known as complant — a precursor to the métayage system. Under this system, a laborer known as a prendeur would agree to cultivate land owned by the...

). In most cases, the prendeurs were giving flexibility in selecting their crop and developing their own vineyard practice.

Many of the viticultural practices developed in this time period would become staples of European viticulture till the 18th century. Varietal
Varietal
"Varietal" describes wines made primarily from a single named grape variety, and which typically displays the name of that variety on the wine label. Examples of grape varieties commonly used in varietal wines are Cabernet Sauvignon, Chardonnay and Merlot...

s were studied more intently to see which vines were the most suitable for a particular area. Around this time, an early concept of terroir
Terroir
Terroir comes from the word terre "land". It was originally a French term in wine, coffee and tea used to denote the special characteristics that the geography, geology and climate of a certain place bestowed upon particular varieties...

emerged as wines from particular places began to develop a reputation for uniqueness. The concept of pruning for quality over quantity emerged, mainly through Cistercian labors, though it would create conflict between the rich landowners who wanted higher quality wines and the peasant
Peasant
A peasant is an agricultural worker who generally tend to be poor and homeless-Etymology:The word is derived from 15th century French païsant meaning one from the pays, or countryside, ultimately from the Latin pagus, or outlying administrative district.- Position in society :Peasants typically...

 laborers whose livelihood depended on the quantity of wine they could sell. The Riesling is the famous example for higher quality of wine. In 1435 Count John IV. of Katzenelnbogen started this successful tradition.

In Burgundy, the Cistercian monks developed the concept of cru vineyards as homogeneous
Homogeneous (chemistry)
A substance that is uniform in composition is a definition of homogeneous. This is in contrast to a substance that is heterogeneous.The definition of homogeneous strongly depends on the context used. In Chemistry, a homogeneous suspension of material means that when dividing the volume in half, the...

 pieces of land that consistently produce wines each vintage
Vintage
Vintage, in wine-making, is the process of picking grapes and creating the finished product . A vintage wine is one made from grapes that were all, or primarily, grown and harvested in a single specified year. In certain wines, it can denote quality, as in Port wine, where Port houses make and...

 that are similar. In areas like the Côte-d'Or
Côte-d'Or
Côte-d'Or is a department in the eastern part of France.- History :Côte-d'Or is one of the original 83 departments created during the French Revolution on 4 March 1790. It was formed from part of the former province of Burgundy.- Geography :...

 the monks divided the land into separate vineyards, many of which are still around today—like Montrachet
Montrachet
Montrachet is an Appellation d'origine contrôlée and Grand Cru vineyard for white wine from Chardonnay in the Côte de Beaune subregion of Burgundy. It is situated across the border between the two communes of Chassagne-Montrachet and Puligny-Montrachet and produces what many consider to be the...

 and La Romanée
La Romanée
La Romanée is an Appellation d'origine contrôlée and Grand Cru vineyard for red wine in the Côte de Nuits subregion of Burgundy, with Pinot Noir as the main grape variety. It is situated within the commune of Vosne-Romanée and is a monopole of the winery Comte Liger-Belair...

.

Growing vines



The vast majority of the world's wine producing regions are found between the temperate
Temperate
In geography, temperate or tepid latitudes of the globe lie between the tropics and the polar circles. The changes in these regions between summer and winter are generally relatively moderate, rather than extreme hot or cold...

 latitude
Latitude
In geography, the latitude of a location on the Earth is the angular distance of that location south or north of the Equator. The latitude is an angle, and is usually measured in degrees . The equator has a latitude of 0°, the North pole has a latitude of 90° north , and the South pole has a...

s of 30° and 50° in each hemisphere
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

. Within these bands, the annual mean
Mean
In statistics, mean has two related meanings:* the arithmetic mean .* the expected value of a random variable, which is also called the population mean....

 temperatures are between 10 and 20 °C (50 and 68 F). The presence of large bodies of water
Body of water
A body of water or waterbody is any significant accumulation of water, usually covering the Earth or another planet. The term body of water most often refers to large accumulations of water, such as oceans, seas, and lakes, but it may also include smaller pools of water such as ponds, puddles or...

 and mountain range
Mountain range
A mountain range is a single, large mass consisting of a succession of mountains or narrowly spaced mountain ridges, with or without peaks, closely related in position, direction, formation, and age; a component part of a mountain system or of a mountain chain...

s can have positive effects on the climate and vines. Nearby lake
Lake
A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...

s and river
River
A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

s can serve as protection for drastic temperature drops at night by releasing the heat that the water has stored during the day to warm the vines.

The vine needs approximately 1300-1500 hours of sunshine during the growing season
Growing season
In botany, horticulture, and agriculture the growing season is the period of each year when native plants and ornamental plants grow; and when crops can be grown....

 and around 690 millimetres (27.2 in) of rain
Rain
Rain is liquid precipitation, as opposed to non-liquid kinds of precipitation such as snow, hail and sleet. Rain requires the presence of a thick layer of the atmosphere to have temperatures above the melting point of water near and above the Earth's surface...

fall throughout the year in order to produce grapes suitable for winemaking. In ideal circumstances, the vine will receive most of the rainfall during the winter and spring months: rain at harvest
Harvest
Harvest is the process of gathering mature crops from the fields. Reaping is the cutting of grain or pulse for harvest, typically using a scythe, sickle, or reaper...

time can create many hazards, such as fungal
Fungus
A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds , as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from plants, animals, and bacteria...

 diseases and berry splitting. The optimum weather
Weather
Weather is the state of the atmosphere, to the degree that it is hot or cold, wet or dry, calm or stormy, clear or cloudy. Most weather phenomena occur in the troposphere, just below the stratosphere. Weather refers, generally, to day-to-day temperature and precipitation activity, whereas climate...

 during the growing season is a long, warm summer that allows the grapes the opportunity to ripen fully and to develop a balance between the levels of acid
Acid
An acid is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red...

s and sugar
Sugar
Sugar is a class of edible crystalline carbohydrates, mainly sucrose, lactose, and fructose, characterized by a sweet flavor.Sucrose in its refined form primarily comes from sugar cane and sugar beet...

s in the grape.

Topography
Topography
Topography is the study of Earth's surface shape and features or those ofplanets, moons, and asteroids...

, too, is important. Hillsides and slopes are preferred over flatter terrain: vines growing on a slope receive a greater strength of the sun rays with sunshine falling on an angle perpendicular
Perpendicular
In geometry, two lines or planes are considered perpendicular to each other if they form congruent adjacent angles . The term may be used as a noun or adjective...

 to the hillside; in flatter terrain, the strength of the sunlight is diluted as it is spread out across a wider surface area. Additionally, a slope affords better drainage, obviating the possibility that the vine might sit in overly moist soil. In cooler regions of the northern hemisphere, south-facing slopes receive more hours of sunlight and are preferred; in warmer climes, north-facing slopes are preferred (in the southern hemisphere, these orientations are reversed).

Hazards




There are many hazards that a viticulturist needs to be aware of when growing vines. These hazards can have an adverse effect on the wine produced from the grape or kill the vine itself. When the vine is flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...

ing it is very susceptible to weather hazards such as strong wind
Wind
Wind is the flow of gases on a large scale. On Earth, wind consists of the bulk movement of air. In outer space, solar wind is the movement of gases or charged particles from the sun through space, while planetary wind is the outgassing of light chemical elements from a planet's atmosphere into space...

s and hail
Hail
Hail is a form of solid precipitation. It consists of balls or irregular lumps of ice, each of which is referred to as a hail stone. Hail stones on Earth consist mostly of water ice and measure between and in diameter, with the larger stones coming from severe thunderstorms...

. Cold temperatures during this period can also bring the onset of millerandage
Millerandage
Millerandage or shot berries is a French term referring to an viticultural problem in which grape bunches contain berries of greatly different size and, most important, different levels of maturity. Its most common cause is too cold or otherwise bad weather during the flowering stage of the vines....

which produces clusters with no seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...

s and varying sizes. Too much heat can have the opposite reaction and produce Coulure
Coulure
Coulure is a potential viticultural hazard that is the result of metabolic reactions to weather conditions that causes a failure of grapes to develop after flowering. In English the word shatter is sometimes used. Coulure is triggered by periods of cold, cloudy, rainy weather or very high...

 that causes grape clusters to either drop to the ground or not fully develop.

Viticultural hazards include:
  • Oidium
    Uncinula necator
    Uncinula necator is a fungus that causes powdery mildew of grape. It is a common pathogen of Vitis species, including the wine grape, Vitis vinifera. The fungus is believed to have originated in North America. European varieties of Vitis vinifera are more or less susceptible to this fungus...

  • Frost
    Frost
    Frost is the solid deposition of water vapor from saturated air. It is formed when solid surfaces are cooled to below the dew point of the adjacent air as well as below the freezing point of water. Frost crystals' size differ depending on time and water vapour available. Frost is also usually...

  • Powdery mildew
    Powdery mildew
    Powdery mildew is a fungal disease that affects a wide range of plants. Powdery mildew diseases are caused by many different species of fungi in the order Erysiphales. It is one of the easier diseases to spot, as its symptoms are quite distinctive. Infected plants display white powdery spots on the...

  • Downy mildew
    Downy mildew
    Downy mildew refers to any of several types of oomycete microbes that are obligate parasites of plants. Downy mildews exclusively belong to Peronosporaceae. In commercial agriculture, they are a particular problem for growers of crucifers, grapes and vegetables that grow on vines...

  • Phylloxera
    Phylloxera
    Grape phylloxera ; originally described in France as Phylloxera vastatrix; equated to the previously described Daktulosphaira vitifoliae, Phylloxera vitifoliae; commonly just called phylloxera is a pest of commercial grapevines worldwide, originally native to eastern North America...

  • Plant virus
    Plant virus
    Plant viruses are viruses that affect plants. Like all other viruses, plant viruses are obligate intracellular parasites that do not have the molecular machinery to replicate without a host. Plant viruses are pathogenic to higher plants...


Green harvest


A green harvest is the removal of immature grape
Grape
A grape is a non-climacteric fruit, specifically a berry, that grows on the perennial and deciduous woody vines of the genus Vitis. Grapes can be eaten raw or they can be used for making jam, juice, jelly, vinegar, wine, grape seed extracts, raisins, molasses and grape seed oil. Grapes are also...

 bunches, typically for the purpose of decreasing yield. In French
French language
French is a Romance language spoken as a first language in France, the Romandy region in Switzerland, Wallonia and Brussels in Belgium, Monaco, the regions of Quebec and Acadia in Canada, and by various communities elsewhere. Second-language speakers of French are distributed throughout many parts...

, it is known as a vendange verte.

Green harvesting is a relatively modern practice most often used to produce fine wine. Removing the tiny, immature grapes while they are still green induces the vine to put all its energy into developing the remaining grapes. In theory this results in better ripening and the development of more numerous and mature flavour compounds. In the absence of a green harvest, a healthy, vigorous vine can produce dilute, unripe grapes.

Many traditionally renowned regions have natural conditions that suppress excess vigor. Examples include the gravelly soil of Bordeaux, the often cool climate of Burgundy, and the meager rainfall of Rioja
La Rioja (Spain)
La Rioja is an autonomous community and a province of northern Spain. Its capital is Logroño. Other cities and towns in the province include Calahorra, Arnedo, Alfaro, Haro, Santo Domingo de la Calzada, and Nájera.-History:...

. In these regions, the vine is prevented from producing too many grapes without human intervention. However, in regions with fertile soil, copious sunlight, and irrigation, the vine can generate huge quantities of characterless grapes. One solution is a green harvest. After fruit set, the quantity of grapes that will result from a vineyard can be estimated. Often the grower has a target yield in mind, measured in tons per acre or hectoliters per hectare. A portion of the grape bunches are cut off, to leave approximately the correct amount.

In Europe, many appellation
Appellation
An appellation is a legally defined and protected geographical indication used to identify where the grapes for a wine were grown; other types of food often have appellations as well...

s restrict the yield permitted from a given area, so there is even more incentive to perform green harvesting when presented with excess crop. Often the excess must be sold for a pittance and used for industrial alcohol production rather than wine.

While the concept of thinning or sacrificing part of the grape crop, i.e. green harvesting, with the aim of improving the quality of the remaining grapes, predates modern critics, the practice has increased in recent times in vineyards found in California and areas where the grapes grow easily. (McCoy)

Field blend



A field blend is a wine that is produced from two or more different grape varieties interplanted in the same vineyard. In the days before precise varietal
Varietal
"Varietal" describes wines made primarily from a single named grape variety, and which typically displays the name of that variety on the wine label. Examples of grape varieties commonly used in varietal wines are Cabernet Sauvignon, Chardonnay and Merlot...

 identification, let alone rigorous clonal selection
Clonal selection
The clonal selection hypothesis has become a widely accepted model for how the immune system responds to infection and how certain types of B and T lymphocytes are selected for destruction of specific antigens invading the body....

, a vineyard might be planted by taking cuttings from another vineyard and therefore approximately copying its genetic makeup. This meant that one vine could be Zinfandel
Zinfandel
Zinfandel is a variety of red grape planted in over 10 percent of California vineyards. DNA fingerprinting revealed that it is genetically equivalent to the Croatian grape Crljenak Kaštelanski, and also the Primitivo variety traditionally grown in Puglia , where it was introduced in the 18th century...

 and the next Carignan. When making wine with little equipment to spare for separate vinification of different varieties, field blends allowed effortless, though inflexible, blending.

Fermentation tanks are now cheap enough that the field blend is an anachronism, and almost all wines are assembled by blending from smaller, individual lots. However, in California some of the oldest (and lowest-yielding) Zinfandel comes from vineyards that are field-blended. Ridge Vineyards
Ridge Vineyards
Ridge Vineyards is a California winery specializing in premium Cabernet Sauvignon, Zinfandel, and Chardonnay wines. Ridge produces wine at two winery locations in northern California...

 owns the Lytton Springs vineyards in Sonoma County, which were planted from 1900 to 1905 in what Ridge calls "a traditional field blend of about seventy percent Zinfandel, twenty percent Petite Sirah, and ten percent Grenache
Grenache
Grenache is one of the most widely planted red wine grape varieties in the world. It ripens late, so it needs hot, dry conditions such as those found in Spain, the south of France, and California's San Joaquin Valley. It is generally spicy, berry-flavored and soft on the palate with a relatively...

and Carignan."