The olive (botanical name Olea europaea, "European olive") is a species of Subtropics evergreen tree in the family Oleaceae. Originating in Anatolia, it is abundant throughout the Mediterranean Basin, with wild subspecies in Africa and western Asia; modern Cultivar are traced primarily to the Near East, Aegean Sea, and Strait of Gibraltar. The olive is the type species for its genus, Olea, and lends its name to the Oleaceae plant family, which includes Syringa vulgaris, jasmine, forsythia, and Fraxinus. The olive fruit is classed botanically as a drupe, similar in structure and function to the cherry or peach. The term oil—now used to describe any Viscosity Hydrophobe liquid—was originally synonymous with olive oil, the Vegetable oil derived from olives.
The olive has deep historical, economic, and cultural significance in the Mediterranean. It is among the oldest Fruit tree domesticated by humans,Nili Liphschitz, Ram Gophna, Moshe Hartman, Gideon Biger, The beginning of olive (olea europaea) cultivation in the old world: A reassessment, Journal of Archaeological Science, Volume 18, Issue 4, 1991, Pages 441–453, ISSN 0305-4403. "Abstract: The olive was one of the first fruit trees cultivated by man. It has been claimed that cultivation of the olive began in Israel during the Chalcolithic Period. Careful botanical examination of pollen grains, stones and wood remains gathered from living trees and from archaeological contexts show that it is impossible to distinguish between wild and cultivated olives. The ample remnants of olive found in archaeological contexts, together with other finds, such as pottery vessels, oil lamps, and olive oil installations, indicate that the earliest widespread use of olives in Israel was in the Early Bronze Age." being first cultivated in the Eastern Mediterranean between 8,000 and 6,000 years ago, most likely in the Levant. The olive gradually disseminated throughout the Mediterranean via trade and human migration starting in the 16th century BC; it took root in Crete around 3500 BC and reached Iberia by about 1050 BC. Olive cultivation was vital to the growth and prosperity of various Mediterranean civilizations, from the Minoans and Myceneans of the Bronze Age to the Classical Greece and Romans of classical antiquity.
The olive has long been prized throughout the Mediterranean for its myriad uses and properties. Aside from its edible fruit, the oil extracted from the fruit has been used in food and for lamp fuel, personal grooming, cosmetics, soap making, lubrication, and medicine, while the wood of olive trees was sometimes used for construction. Owing to its utility, resilience, and longevity—an olive tree can allegedly live for thousands of years—the olive also held symbolic and spiritual importance in various cultures; its branches and leaves were used in religious rituals, funerary processions, and public ceremonies, from the ancient Olympic games to the coronation of Israelite kings. Ancient Greeks regarded the olive tree as sacred and a symbol of peace, prosperity, and wisdom—associations that have persisted. The olive is a core ingredient in traditional Middle Eastern and Mediterranean cuisines, particularly in the form of olive oil, and a defining feature of local landscapes, commerce, and folk traditions.
The olive is cultivated in all countries of the Mediterranean, as well as in Australia, New Zealand, the Americas, and South Africa. Spain, Italy, and Greece lead the world in commercial olive production; other major producers are Turkey, Tunisia, Syria, Morocco, Algeria, and Portugal. There are thousands of cultivars of olive tree, and the fruit of each cultivar may be used primarily for oil, for eating, or both, although some varieties are grown as sterile ornamental Shrub, and are known as Olea europaea Montra, dwarf olive, or little olive. Approximately 80% of all harvested olives are processed into oil, while about 20% are for consumption as fruit, generally referred to as "table olives".
Small, white flowers are borne generally on the previous year's wood, in springing from leaf axils. Each flower is made of four yellowish white petals fused at the bottom joined to a base of four fused green sepals. The flower buds grow slowly from 4 to 6 weeks before they reach a length of about 2 cm and bloom, they bloom quicker between 5-6 days in hot weather and 2 weeks in colder areas. The flowers also pollinate and fertilize faster in hotter climates.
The fruit is a small drupe, long when ripe, thinner-fleshed and smaller in wild plants than in orchard cultivars. Olives are harvested in the green to purple stage. O. europaea contains a pyrena commonly referred to in American English as a "pit", and in British English as a "stone".
The subspecies europaea is divided into two varieties, the europaea, which was formerly named Olea sativa, with the called "olivasters", and silvestris, which corresponds to the old wildly growing Mediterranean species Olea oleaster, with the seedlings called "oleasters". The sylvestris is characterized by a smaller, shrubby tree that produces smaller fruits and leaves.
The subspecies O. e. cerasiformis is tetraploid, and O. e. maroccana is hexaploid. Wild-growing forms of the olive are sometimes treated as the species Olea oleaster, or "oleaster". The trees referred to as "Canarium album" and "Canarium pimela" olives in Southeast Asia are not actually olives but species of Canarium.
Since many olive cultivars are self-sterile or nearly so, they are generally planted in pairs with a single primary cultivar and a secondary cultivar selected for its ability to fertilize the primary one. In recent times, efforts have been directed at producing hybrid cultivars with qualities useful to farmers, such as resistance to disease, quick growth, and larger or more consistent crops.
The olive plant was first cultivated in the Mediterranean between 8,000 and 6,000 years ago. Domestication likely began in the Levant, based on archeological findings in ancient tombs—including written tablets, olive pits, and olive wood fragments—as well as genetic analyses.
For thousands of years, olives were grown primarily for lamp oil rather than for culinary purposes, as the natural fruit has an extremely bitter taste.Kanakis P., Termentzi A., Michel T., Gikas E., Halabalaki M., Skaltsounis A.-L. From olive drupes to olive Oil. An HPLC-orbitrap-based qualitative and quantitative exploration of olive key metabolites. Planta Medica. 2013;79(16):1576–1587. doi: 10.1055/s-0033-1350823 It is very likely that the first mechanized agricultural methods and tools were those designed to produce olive oil;WORLD OLIVE ENCYCLOPAEDIA, International Olive Oil Council Principe de Vergara 154 28(X)2 Madrid (Spain), p. 24. the earliest olive oil production dates back some 6,500 years ago in coastal Canaan (present-day Israel).Galili E., Stanley D. J., Sharvit J., Weinstein-Evron M. Evidence for earliest olive-oil production in submerged settlements off the Carmel Coast, Israel. Journal of Archaeological Science. 1997;24(12):1141–1150. doi: 10.1006/jasc.1997.0193 As far back as 3000BC, olives were grown commercially in Crete and may have been the main source of wealth for the Minoan civilization.
The exact ancestry of the cultivated olive is unknown. Fossil olea pollen has been found in Macedonia and other places around the Mediterranean, indicating that this genus is an original element of the Mediterranean flora. Fossilized leaves of olea were found in the paleosol of the volcanic Greek island of Santorini and dated to about 37,000 BP. Imprints of larvae of olive whitefly Aleurobus olivinus were found on the leaves. The same insect is commonly found today on olive leaves, showing that the plant-animal co-evolutionary relations have not changed since that time.Friedrich W.L. (1978). Fossil plants from Weichselian interstadials, Santorini (Greece) II , published in the "Thera and the Aegean World II", London, pp. 109–128. Retrieved on 2011-12-07. Other leaves found on the same island date back to 60,000 BP, making them the oldest known olives from the Mediterranean.
The earliest evidence of the olive tree in Egypt traces back to the Eighteenth Dynasty (1570–1345 BC), during the same period the Phoenicians began distributing it across the Mediterranean. However, scenes on the walls of the tomb of Teti (ruled c. 2345 BC to c. 2333 BC) show olive fruits and trees, though it is unclear if these represent domestic cultivation. Pharoah Ramesses III (reigned 1186–1155 BC) promoted cultivating olive trees and offered the olive oil extracted from Heliopolis to the Sun God Ra; papyrus manuscripts dated to his reign (c. 1550 BC), as well as temple engravings, depict the growing of olive trees and the use of olive oil in cooking, lamps, cosmetics, medicine and embalming. Pharoah Tutankhamun, who ruled from ca. 1333 to 1323 BC, wore a garland of olive branches originated from Dakhla Oasis, 360 km to the east. Egyptian mummies dating back to the 20-25th dynasties (c. 1185 BC to c. 656 BC) have also been found wearing olive wreaths.
While there is no evidence of olive cultivation in Mesopotamia, olive wood appears as early as the mid third millennium BC; the site of Emar in present-day Syria has olive wood and olive pits dating to the Middle Bronze Age (2000–1600 BC). The Code of Hammurabi, a compilation of laws and edicts made by King Hammurabi of the Old Babylonian Empire (reigning from c. 1792 to c. 1750 BC), makes repeated references to olive oil as a key commodity. The Assyria (858–627 BC) may have expanded into the southern Levant partly to secure control over its lucrative olive oil production.Van de Mieroop M. A history of the ancient Near East ca. ca. 3000 323 BC. Chichester: Blackwell Publishing; 2016.
From the sixth century BC onwards, the olive continued spreading toward the central and western Mediterranean through colonization and commerce, reaching Sicily, Libya, and Tunisia. From there, it expanded into southern Italy among the various Etruscan, Sabine, and Italic peoples. The introduction of the olive tree to mainland Italy allegedly occurred during the reign of Lucius Tarquinius Priscus (616–578 BC), possibly from Tripoli (Libya) or Gabes (Tunisia). Cultivation moved as far upwards as Liguria near the border with France. When the Romans arrived in North Africa beginning in the second half of the first century BC, the native Berbers knew how to Grafting wild olives and had highly developed its cultivation throughout the region.
The olive's expansion and cultivation reached its greatest extent through Rome's gradual conquest and settlement across virtually the entire Mediterranean; the Romans continued propagating the olive for commercial and agricultural purposes, as well as to assimilate local populations. It was introduced in present-day Marseille around 600 BC and spread from there to the whole of Gaul (modern France). The olive tree made its appearance in Sardinia following Roman conquest in the third century BC, though it may not have reached nearby Corsica until after the fall of the western Roman Empire in the fifth century AD.
Although olive growing was introduced to Spain by the Phoenicians some time in 1050 BC, it did not reach a larger scale until the arrival of Scipio Africanus (212 BC) during the Second Punic War against Carthage. After the Third Punic War (149–146 BC), olives occupied a large stretch of the Hispania Baetica valley in southwest Spain and spread towards the central and Mediterranean coastal areas of the Iberian Peninsula, including Portugal. Through the second century AD, this region would become the largest source of olives and olive oil within the empire. Olive became a core part of the Roman diet, and by extension a major economic pillar; the cultivation, harvesting, and trade in olives and their derived goods sustained many livelihoods and regions. The emperor Hadrian (117–138 AD) passed laws prompting olive cultivation by exempting individuals who grew olive trees from rent payments on their land for ten years.
The degree to which the olive benefited from the Romans is demonstrated by the significant decline in olive planting and olive oil production that followed the collapse of the Roman Empire.Julie Angus, Olive Odyssey: searching for the secrets of the fruit that seduced the world. ISBN 9781553655145. P. 80. Beginning in the early eighth century AD, Muslim Arabs and North Africans brought their own varieties of olives during their Al-Andalus, reinvigorating and expanding olive growing throughout the peninsula. The spread and importance of olives during subsequent Islamic rule is reflected in the Arabic roots of the Spanish words for olive ( aceituna), oil ( aceite), and wild olive tree ( acebuche) and the Portuguese words for olive ( azeitona) and olive oil ( azeite).
Spanish missionaries established the olive tree in California between 1769 and 1795 at Mission San Diego de Alcalá. Orchards were started at other missions, but by 1838, only two olive orchards were confirmed in California. Cultivation for oil gradually became a highly successful commercial venture from the 1860s onward.
Olive growing in the United States is primarily concentrated in warmer regions like California, Texas, New Mexico, Arizona, Georgia, and Florida. California is by far the largest olive producer in the U.S., accounting for 95 percent of domestic olives; as of 2021, there are roughly 36,000 acres under olive cultivation in the U.S., of which about 35,000 acres are in California. However, the industry is also expanding into the southeastern U.S., with Florida and Georgia experiencing growth in olive farming.
Since 2010, Pakistan has been pursuing large scale commercial olive production, which it identified as a strategic national priority to reduce dependence on foreign oils and expand economic opportunity. As part of the national Ten Billion Tree Tsunami Project launched in 2019, which aimed to plant 10 billion trees to mitigate climate change and environmental degradation, the Khyber Pakhtunkhwa provincial government planted thousands of olives to symbolize peace and provide commercial opportunities in the war-torn region. By 2020, with the help of experts from Spain and Italy, Pakistan imported thousands of trees and identified 10 million acres for growing olives. The following year, the federal Ministry of Climate Change launched the Olive Trees Tsunami Project to plant nearly 10 million hectares of olive trees. In 2022, Pakistan announced its intention to join the International Olive Council as part of ongoing efforts to develop its domestic olive industry. As of January 2025, the country had 5.6 million cultivated olive trees, with 500,000 to 800,000 new trees planted annually, as well as 80 million wild olive trees. Punjab province plans to plant 50 million olive trees on about 9.8 million acres by 2026.
Commercial olive oil production started in India in 2016, following the planting of olive saplings imported from Israel in Rajasthan's Thar Desert in 2008. Production was spearheaded by Rajasthan Olive Cultivation Limited, a state government-funded agency that offered subsidies and incentives for growing olives, with support from Israeli experts. Olive farms continued expanding into 2020 but saw a precipitous decline in size and production volume by 2023, due to the difficult climate and declining government interest and support.
The Ancient Greece smeared olive oil on their bodies and hair as a matter of grooming and good health. Olive oil was used to anoint kings and athletes in ancient Greece. It was burnt in the sacred lamps of temples and was the "eternal flame" of the original Olympic games, whose victors were crowned with its leaves. The olive appears frequently, and often prominently, in ancient Greek literature. Homer's Odyssey (c. eighth century BC), Odysseus crawls beneath two shoots of olive that grow from a single stock,Homer, Odyssey, book 5". and in the Iliad, (XVII.53ff) there is a metaphoric description of a lone olive tree in the mountains by a spring; the Greeks observed that the olive rarely thrives at a distance from the sea, which in Greece invariably means up mountain slopes. Greek myth attributed to the primordial culture-hero Aristaeus the understanding of olive husbandry, along with cheese-making and beekeeping."He learned from the how to curdle milk, to make bee-hives, and to cultivate olive-trees, and was the first to instruct men in these matters." (Diodorus Siculus, 4.81.1). Olive was one of the woods used to fashion the most primitive Greek , called xoanon, referring to their wooden material; they were reverently preserved for centuries.Toward the end of the second century AD, the traveler Pausanias saw many such archaic cult figures.
In an archaic Athenian Origin myth, Athena won the patronage of Attica from Poseidon with the gift of the olive. According to the fourth-century BC father of botany, Theophrastus, olive trees ordinarily attained an age around 200 years,Theophrastus, On the Causes of Plants, 4.13.5. noted by Isager, Signe & Skydsgaard, Jens Erik (1992). Ancient Greek Agriculture, An introduction. Routledge. p. 38. . and he mentions that the very olive tree of Athena still grew on the Acropolis; it was still to be seen there in the second century AD,"...which is still shown in the Pandroseion" (pseudo-Apollodorus, Bibliotheke, 3.14.1). and when Pausanias was shown it , he reported "Legend also says that when the Persians fired Athens the olive was burnt down, but on the very day it was burnt it grew again to the height of two ."Pausanias, Description of Greece 1.27.1. Because olive suckers sprout readily from the stump, and some existing olive trees are purportedly many centuries old, it is possible that the olive tree of the Acropolis dated to the Bronze Age. The olive remained sacred to Athens and its patron deity Athena, appearing on its coinage. According to another myth, Elaea—whose name translates to "olive"—was an accomplished athlete killed by fellow athletes out of envy; owing to her impressive achievement, Athena and Gaia turn her into an olive tree as a reward.
The olive and its properties were subject to early scientific and empirical observation. Theophrastus, in On the Causes of Plants, states that the cultivated olive must be vegetatively propagated; indeed, the pits give rise to thorny, wild-type olives, spread far and wide by birds. He also reports how the bearing olive can be grafted on the wild olive, for which the Greeks had a separate name, kotinos.Isager, Signe & Skydsgaard, Jens Erik (1992). Ancient Greek Agriculture, An introduction. Routledge. p. 35. In his Enquiry into Plants, Theophrastus states that the olive can be propagated from a piece of the trunk, the root, a twig, or a stake. Homer described olive oil as "liquid gold", while Hippocrates (c. 460 BC – c. 375 BC), widely regarded as the father of medicine, considered it "the great healer".
The olive tree was subject to many treatises and agronomic works by the Romans. Pliny the Elder, in his first century AD encyclopedia, Naturalis Historia, describes at least 22 different varieties and qualities of olive trees, detailing their respective techniques for cultivation and production. Pliny also observes that an olive tree is one of only three plants—along with a vine and Ficus—growing in the middle of the Roman Forum, which served as the center of daily life in the city; the olive was purportedly planted to provide shade. (The garden was recreated in the 20th century).
Roman poet Horace mentions the olive in reference to his own diet, which he describes as very simple: "As for me, olives, , and smooth mallows provide sustenance."" Me pascunt olivae, me cichorea levesque malvae." Horace, Odes 1.31.15, c. 30 BC Roman architect and engineer Vitruvius describes of the use of charred olive wood in tying together walls and foundations in his .Pollio, Vitruvius (1914). The Ten Books on Architecture. Harvard University Press, Book 1, Ch. V, Sec. 3, p. 22 Olive cultivation and production was also recognized for its commercial and economic importance; according to Cato the Younger, among the various tasks of the pater familias (the family patriarch and head of household) was that of keeping an account of the olive oil. The city of Rome designated a special area for negotiating and selling olive oil that was managed by negotiatores oleari, who were analogous to stockbrokers.
The olive's importance in Israel is expressed in the parable of Jotham in Judges 9:8–9: "One day the trees went out to anoint a king for themselves. They said to the olive tree, 'Be our king.' But the olive tree answered, 'Should I give up my oil, by which both gods and humans are honored, to hold sway over the trees? The olive tree is also analogized to a righteous man (Psalm 52:8; Hosea 14:6) whose "children will be like vigorous young olive trees" (Psalm 128:3).
Deuteronomy characterizes the "Promised Land" of the Hebrews as containing olive groves (6:11) and subsequently lists olives as one of the Seven Species that are special products of the Land of Israel (8:8).
Olive oil features prominently in the Jewish holidays of Hanukkah, which commemorates the recovery of Jerusalem and subsequent rededication of the Second Temple during the Maccabean Revolt against the Seleucid Empire in the 2nd century BC. According to the Talmud, the central text of Rabbinic Judaism, after Seleucid forces had been driven from the Temple, the Maccabees discovered that almost all the ritual olive oil for the Temple menorah had been profaned. They found only single container with just enough Kohen Gadol to keep the menorah lit for a single day; however, it burned for eight days—the time needed for new oil to have been prepared—a miracle that forms a major part of Hanukkah celebrations. Subsequently, the olive tree and its oil have come to represent the strength and persistence of the Jews. In common with other Mediterranean cultures, the Jewish people used it for many practical and ritualistic purposes, from fuel and medicine to cosmetics and even currency; as in Greek and Roman societies, athletes were cleansed by covering their skin with oil then scraping it to remove the dirt. Jews who settled in foreign lands often became olive merchants.
Due to its importance in the Hebrew Bible, the olive has significant national meaning in modern Israeli culture. Two olive branches appear as part of Israel's emblem, which may have been inspired by the vision of biblical Hebrew prophet Zechariah, who describes seeing a menorah flanked by an olive tree on each side;Mishory, Alec. The Israeli Emblem. Jewish Virtual Library. [5]. American-Israeli Cooperative Enterprise. Accessed 9 Jul. 2012. the trees represent Zerubbabel and Joshua, the governor and high priest, respectively. The olive tree was declared the unofficial national tree of Israel in 2021 by a survey of Israelis; it is often planted during Tu BiShvat and its fruit is a customary part of the accompanying seder.
Gethsemane, an olive garden at the foot of the Mount of Olives, whose name derives from the Hebrew word for "oil press", is where Jesus underwent his agonized prayer to God and was ultimately betrayed and arrested before his crucifixion. According to Eastern Orthodox Church tradition, it is where the Virgin Mary was buried and was assumed into heaven after her dormition on Mount Zion. Gethsemane became a focal point for Christian pilgrims during the Middle Ages and remains revered in Christianity; many of its olive trees, which are purportedly among the oldest living trees in the world, are divided among various churches.
The apostle Paul uses the olive tree as an allegory in his Epistle to the Romans, comparing Israelites to a tame olive tree and Gentile to a wild olive branch (Romans 11:17–24).The cultivated olive tree is pruned and nurtured so as to bear fruit, whereas its barren branches are trimmed and discarded; God has preserved the holy root of Israel so that the wild branches (the Gentiles) can be grafted onto it and thus share in the blessings of the cultivated tree (Israel)
The harvest season is referred to as "Palestine's wedding" and is considered a national holiday when schools close for two days so that pupils and teachers can join in the harvest. This holiday allows community and family members to gather and serves as a ritual that encompasses their values surrounding family, labour, community and aid for other members of the community that do not possess land. This is practised through the tradition of leaving fruit on a tree during the harvest so that those who do not have land and are unable to take part in the harvest can still reap the benefits.
The olive tree's enduring cultural and economic significance to the Palestinians has put it at the center of the ongoing Israeli–Palestinian conflict; an estimated 800,000 olive trees have been uprooted by Israeli authorities and settlers Six-Day War, and groves are frequently targeted in attacks or acts of vandalism. These destructions are considered a way to forcibly displace Palestinians and seize their land. Israeli military uproots thousands of Palestinian olive trees in West Bank
Thomas Jefferson, a founding father and third president of the United States, was a great admirer of olives and olive oil, regarding the olive tree as "the richest gift of heaven", "one of the most precious productions of nature", and "the most interesting plant in existence". Jefferson's fascination stemmed from his experiences in Europe, particularly France and Italy, while serving as the U.S. Minister to France in the late 1780s. He was impressed by the olive tree's resilience and suitability for various climates, taking detailed notes of its various "virtues" and qualities; he also observed the widespread use of olive oil and encouraged its consumption for its health benefits and ability to provide "a proper and comfortable nourishment" compared to existing staples in the U.S. such as rice.Jefferson to Drayton, July 30, 1787, in PTJ, 11:649. Transcription available at Founders Online.
Jefferson believed the olive tree would be a valuable crop in America and could help alleviate poverty and improve the lives of enslaved people; he wrote letters to various agricultural societies urging them to consider introducing olive cultivation in the U.S., advocating for "an olive tree planted for every American slave", particularly in the American South. Jefferson experimented with growing olive trees at his home in Monticello, Virginia and attempted to establish a domestic olive oil industry, expressing bitter disappointment when this effort failed in the early 1810s.
Jefferson remained a lifelong connoisseur of olive oil, which "had joined the exclusive company of wine and books as a ... 'necessary of life; every year until his death, he imported four to five gallons of "virgin oil of Aix-en-Provence" from France, and at least one fragment of an olive oil bottle has been unearthed at Monticello.
Spain accounts for almost half of global olive oil production; other major producers are Portugal, Italy, Tunisia, Greece and Turkey. Per capita consumption is highest in Greece, followed by Italy and Spain.
The composition of olive oil varies with the cultivar, elevation, time of harvest and extraction process. It consists mainly of oleic acid (up to 83%), with smaller amounts of other including linoleic acid (up to 21%) and palmitic acid (up to 20%). Extra virgin olive oil (EVOO) is required to have no more than 0.8% free acidity and fruity flavor characteristics.
The curing process may take from a few days with lye, to a few months with brine or salt packing. With the exception of California style and salt-cured olives, all methods of curing involve a major fermentation involving bacteria and yeast that is of equal importance to the final table olive product.Kailis, Stanley G. & Harris, David John (2007). Producing table olives. Landlinks Press. Traditional cures, using the natural microflora on the fruit to induce fermentation, lead to two important outcomes: the leaching out and breakdown of oleuropein and other unpalatable phenolic compounds, and the generation of favourable metabolites from bacteria and yeast, such as organic acids, probiotics, glycerol, and esters, which affect the sensory properties of the final table olives. Mixed bacterial/yeast olive fermentations may have probiotic qualities. Lactic acid is the most important metabolite, as it lowers the pH, acting as a natural preservative against the growth of unwanted pathogenic species. The result is table olives which can be stored without refrigeration. Fermentations dominated by lactic acid bacteria are, therefore, the most suitable method of curing olives. Yeast-dominated fermentations produce a different suite of metabolites which provide poorer preservation, so they are corrected with an acid such as citric acid in the final processing stage to provide microbial stability.
The many types of preparations for table olives depend on local tastes and traditions. The most important commercial examples are listed below.
Olives are cultivated in many regions of the world with Mediterranean climates, such as South Africa, Chile, Peru, Pakistan, Australia, and the western United States (particularly California), as well as in areas with temperate climates such as New Zealand and the Córdoba Province, Argentina. Enciclopedia Universal Europeo Americana. Volume 15. Madrid (1981). Espasa-Calpe S.A. (Complete Encyclopedia) and
Only a handful of olive varieties can be used to cross-pollinate. 'Pendolino' olive trees are partially self-fertile, but pollenizers are needed for a large fruit crop. Other compatible olive tree pollinators include 'Leccino' and 'Maurino'. 'Pendolino' olive trees are used extensively as pollinizers in large olive tree groves.
Olives are propagated by various methods. The preferred ways are cuttings and layers; the tree roots easily in favourable soil and throws up Basal shoot from the stump when cut down. However, yields from trees grown from suckers or seeds are poor; they must be budding or grafting onto other specimens to do well.Lewington and Parker, 114. Branches of various thickness cut into lengths around planted deeply in ground soon vegetate. Shorter pieces are sometimes laid horizontally in shallow trenches and, when covered with a few centimetres of soil, rapidly throw up sucker-like shoots. In Greece, grafting the cultivated tree on the wild tree is a common practice. In Italy, embryonic buds, which form small swellings on the stems, are carefully excised and planted under the soil surface, where they soon form a vigorous shoot.
The olive is also sometimes grown from seed. To facilitate germination, the oily pericarp is first softened by slight rotting, or soaked in hot water or in an alkaline solution.
In situations where extreme cold has damaged or killed the olive tree, the rootstock can survive and produce new shoots which in turn become new trees. In this way, olive trees can regenerate themselves. In Tuscany in 1985, a very severe frost destroyed many productive and aged olive trees and ruined many farmers' livelihoods. However, new shoots appeared in the spring and, once the dead wood was removed, became the basis for new fruit-producing trees.
Olives grow very slowly, and over many years, the trunk can attain a considerable diameter. A. P. de Candolle recorded one exceeding in girth. The trees rarely exceed in height and are generally confined to much more limited dimensions by frequent pruning. Olives are very hardy and are resistant to disease and fire. Its root system is robust and capable of regenerating the tree even if the above-ground structure is destroyed.
The crop from old trees is sometimes enormous, but they seldom bear well two years in succession, and in many cases, a large harvest occurs every sixth or seventh season. Where the olive is carefully cultivated, as in Liguria, Languedoc, and Provence, the trees are regularly pruned. The pruning preserves the flower-bearing shoots of the preceding year, while keeping the tree low enough to allow the easy gathering of the fruit.
A fungus, Cycloconium oleaginum, can infect the trees for several successive seasons, causing great damage to plantations. A species of bacterium, Pseudomonas savastanoi pv. oleae, induces tumour growth in the shoots. Certain Lepidoptera feed on the leaves and flowers. Xylella fastidiosa bacteria, which can also infect citrus fruit and vines, has attacked olive trees in Apulia, southern Italy, causing olive quick decline syndrome (OQDS). The main vector is Philaenus spumarius (meadow spittlebug).
A pest that spreads through olive trees is the black scale bug, a small black scale insect that resembles a small black spot. They attach themselves firmly to olive trees and reduce the quality of the fruit; their main predators are wasps. The Plum curculio eats the edges of leaves, leaving sawtooth damage.Burr, M. (1999). Australian Olives. A guide for growers and producers of virgin oils, 4th edition. .
eat the bark of olive trees and can do considerable damage, especially to young trees. If the bark is removed around the entire circumference of a tree, it is likely to die. Voles and mice also do damage by eating the roots. At the northern edge of their cultivation zone, for instance in northern Italy, southern France and Switzerland, olive trees suffer occasionally from frost. Gales and long-continued rains during the gathering season also cause damage. In the colder Mediterranean hinterland, olive cultivation is replaced by other fruits, typically the chestnut.
In some other parts of the world where it has been introduced, most notably South Australia, the olive has become a major weed that displaces native vegetation. In South Australia, its seeds are spread by the introduced red fox and by many bird species, including the Common starling and the native emu, into woodlands, where they germinate and eventually form a dense canopy that prevents regeneration of native trees. As the climate of South Australia is very dry and bushfire prone, the oil-rich feral olive tree substantially increases the fire hazard of native sclerophyll woodlands. Olives as Weeds Animal and Plant Control Commission of South Australia
Table olive varieties are more difficult to harvest, as workers must take care not to damage the fruit; baskets that hang around the worker's neck are used. In some places in Italy, Croatia, and Greece, olives are harvested by hand because the terrain is too mountainous for machines. As a result, the fruit is not bruised, which leads to a superior finished product. The method also involves sawing off branches, which is healthy for future production."Unusual Olives", Epikouria Magazine, Spring/Summer 2006
The amount of oil contained in the fruit differs greatly by cultivar; the Fruit anatomy is usually 60–70% oil. Typical yields are of oil per tree per year.
According to the Food and Agriculture Organization, the 10 leading producers are all in the Mediterranean region and responsible for 95% of the world's olives. Spain is the world's leading producer and concentrates the largest land area to olive cultivation, with more than 180 million trees spanning over 2,507,684 hectares, followed by Tunisia (1,746,360 ha) and Italy (1,143,363 ha). In Italy, olive tree cultivation is widespread in the south, accounting for three quarters of its production; it is less abundant in the colder north of Italy, although growth has increased, particularly in the more temperate of Liguria and the hills around Lake Garda. Approximately 170 million plants are distributed over one million farms.
In terms of olive oil output, Spain is by far the largest producer, making up 25% of the global supply, followed by Italy, Morocco, and Tunisia. The European Union is responsible for nearly 60% of the world's olive oil.
During the crushing, kneading and extraction of olive fruit to obtain olive oil, oleuropein, demethyloleuropein and ligstroside are hydrolysis by endogenous to form , , and aldehydic . Polyphenol content also varies with olive cultivar and the manner of presentation, with plain olives having higher contents than those that are pitted or stuffed.
Cultivars
History
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Expansion and propagation
Outside the Mediterranean
Americas
Asia
Global expansion
Symbolic and cultural significance
Ancient Greece
Ancient Egypt
Ancient Rome
Judaism and Israel
Christianity
Islam
Palestine
United States
United Nations
Uses and properties
Olive oil
Table olives
Fermentation and curing
Olive wood
Ornamental
Olive mill wastewater
Olive stone
Environmental health and sustainability
Cultivation
Growth and propagation
Pests, diseases, and weather
As an invasive species
Harvesting
Longevity
Oldest living trees
Global production
Nutrition
Phytochemicals
Allergenic potential
See also
External links
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