Avocado

The avocado, alligator pear or avocado pear (Persea americana) is an evergreen tree in the laurel family (Lauraceae). It is native to the Americas and was first domesticated in Mesoamerica more than 5,000 years ago. It was prized for its large and unusually oily fruit. The tree likely originated in the highlands bridging south-central Mexico and Guatemala. Avocado trees have a native growth range from Mexico to Costa Rica.
Its fruit, sometimes also referred to as an alligator pear or avocado pear, is botanically a large berry containing a single large seed. Sequencing of its genome showed that the evolution of avocados was shaped by polyploidy events and that commercial varieties have a hybrid origin. Avocado trees are partly self-pollinating, and are often propagated through grafting to maintain consistent fruit output. Avocados are presently cultivated in the tropical and Mediterranean climates of many countries. As of 2023, Mexico is the world's leading producer of avocados, supplying 29% of the global harvest of 10.5 million tonnes.
The fruit of domestic varieties have smooth, buttery, golden-green flesh when ripe. Depending on the cultivar, avocados have green, brown, purplish, or black skin, and may be pear-shaped, egg-shaped, or spherical. For commercial purposes, the fruits are picked while unripe and ripened after harvesting. The nutrient density and high fat content of avocado flesh are advantages for various cuisines, including vegetarian diets.
In major production regions like Chile, Mexico and California, the water demands of avocado farms place strain on local resources. Avocado production is implicated in other externalities, including deforestation and human rights concerns associated with the partial control of their production in Mexico by organized crime. Global warming is expected to result in significant changes to the suitable growing zones for avocados, and place additional pressures on the locales in which they are produced due to heat waves and drought.
Persea americana is a tree that grows to 9–20 m (30–66 ft) with a trunk diameter between 0.3–0.6 m (1–2 ft). The leaves are 8–25 cm (3–10 in) long and alternately arranged.
Panicles of flowers with deciduous bracts arise from new growth or the axils of leaves. The tree flowers thousands of blossoms every year. Avocado blossoms sprout from racemes near the leaf axils; they are small and inconspicuous 5–10 mm (3⁄16–3⁄8 in) wide. They have no petals but instead two whorls of three pale-green or greenish-yellow downy perianth lobes, each blossom has 9 stamens with 2 basal orange nectar glands.
The avocado fruit is a climacteric, single-seeded berry, due to the imperceptible endocarp covering the seed, rather than a drupe. The pear-shaped fruit is usually 7–20 cm (3–8 in) long, weighs between 100 and 1,000 g (3+1⁄2 and 35+1⁄2 oz), and has a large central seed, 5–6.4 cm (2–2+1⁄2 in) long. Early wild avocados prior to domestication had much smaller seeds around 2.1–2.2 centimetres (0.83–0.87 in) in diameter, likely corresponding to smaller fruit size.
The species produces various cultivars with larger, fleshier fruits with a thinner exocarp because of selective breeding by humans.
The species was scientifically named by the British botanist Philip Miller in 1768. The genus Persea to which the avocado belongs is considered to have a North American origin, with Persea suggested to have diversified in Central America during the Pleistocene epoch. The modern avocado is thought to have speciated from other Persea during the Pleistocene, estimated at around either 1.3 million or 430,000 years ago. A number of authors, including Connie Barlow in her 2001 book The Ghosts of Evolution, have speculated that the avocado is an "evolutionary anachronism" with megafaunal dispersal syndrome (a concept originally proposed in the 1980s by Paul S. Martin and Daniel H. Janzen), arguing that the avocado likely coevolved dispersal of its large seed by now-extinct megafauna. Barlow proposed that the dispersers included the gomphothere (elephant relative) Cuvieronius, as well as ground sloths, toxodontids, and glyptodonts. The concept of evolutionary anachronisms/megafaunal dispersal syndrome has been criticised by some authors, who note that many large fruit are readily dispersed by non-megafaunal animals, with it being noted that living agoutis disperse avocado seeds, with spectacled bears have also having been observed eating domestic avocados.
The earliest known written account of the avocado in Europe is that of Martín Fernández de Enciso (c. 1470 – 1528) in 1519 in his book, Suma De Geographia Que Trata De Todas Las Partidas Y Provincias Del Mundo, while describing the native settlement of Yaharo (present-day Dibulla, Colombia). The first detailed account that unequivocally describes the avocado was given by Gonzalo Fernández de Oviedo y Valdés in his work Sumario de la natural historia de las Indias in 1526, while holding administrative Spanish colonial duties in Santo Domingo and visiting Castilla de Oro. The first written record in English of the use of the word 'avocado' was by Hans Sloane, who coined the term, in a 1696 index of Jamaican plants.
The word avocado comes from the Spanish aguacate, which derives from the Nahuatl (Mexican) word āhuacatl [aːˈwakat͡ɬ], which goes back to the proto-Aztecan *pa:wa. In Molina's Nahuatl dictionary "auacatl" is given also as the translation for compañón "testicle", and this has been taken up in popular culture where a frequent claim is that testicle was the word's original meaning. This is not the case, as the original meaning can be reconstructed as "avocado" – rather the word seems to have been used in Nahuatl as a euphemism for "testicle".
The modern English name comes from a rendering of the Spanish aguacate as avogato. The earliest known written use in English is attested from 1697 as avogato pear, later avocado pear (due to its shape), a term sometimes corrupted to alligator pear.
In Central American, Caribbean Spanish-speaking countries, and Spain it is known by the Mexican Spanish name aguacate, while South American Spanish-speaking countries Argentina, Chile, Perú and Uruguay use a Quechua-derived word, palta. In Portuguese, it is abacate. The Nahuatl āhuacatl can be compounded with other words, as in ahuacamolli, meaning avocado soup or sauce, from which the Spanish word guacamole derives.
In the United Kingdom the term avocado pear, applied when avocados first became commonly available in the 1960s, is sometimes used.
Originating as a diminutive in Australian English, a clipped form, avo, has since become a common colloquialism in South Africa and the United Kingdom.
It is known as "butter fruit" in parts of India and Hong Kong.
Domestication, leading to genetically distinct cultivars, possibly originated in the Tehuacan Valley in the state of Puebla, Mexico. There is evidence for three possible separate domestications of the avocado, resulting in the currently recognized Guatemalan (quilaoacatl), Mexican (aoacatl) and West Indian (tlacacolaocatl) landraces. The Guatemalan and Mexican and landraces originated in the highlands of those countries, while the West Indian landrace is a lowland variety that ranges from Guatemala, Costa Rica, Colombia, Ecuador to Peru, achieving a wide range through human agency before the arrival of the Europeans. The three separate landraces were most likely to have already intermingled in pre-Columbian America and were described in the Florentine Codex. As a result of artificial selection, the fruit and correspondingly the seeds of cultivated avocados became considerably larger relative to their earlier wild forebears millennia before the Columbian exchange.
The earliest residents of northern coastal Peru were living in temporary camps in an ancient wetland and eating avocados, along with chilies, mollusks, sharks, birds, and sea lions. The oldest discovery of an avocado pit comes from Coxcatlan Cave, dating from around 9,000 to 10,000 years ago. Other caves in the Tehuacan Valley from around the same time period also show early evidence for the presence and consumption of avocado. There is evidence for avocado use at Norte Chico civilization sites in Peru by at least 3,200 years ago and at Caballo Muerto in Peru from around 3,800 to 4,500 years ago.
The avocado tree also has a long history of cultivation in Central and South America, likely beginning as early as 5,000 BC. A water jar shaped like an avocado, dating to AD 900, was discovered in the pre-Inca city of Chan Chan.
The plant was introduced to Spain in 1601, Indonesia around 1750, Mauritius in 1780, Brazil in 1809, the United States mainland in 1825, South Africa and Australia in the late 19th century, and the Ottoman Empire in 1908. In the United States, the avocado was introduced to Florida and Hawaii in 1833 and in California in 1856.
The name avocado has been used in English since at least 1764, with minor spelling variants such as avogato attested even earlier. The avocado was commonly referred to in California as ahuacate and in Florida as alligator pear until 1915, when the California Avocado Association popularized the term avocado.
As a subtropical species, avocados need a climate without frost and with little wind. High winds reduce the humidity, dehydrate the flowers, and affect pollination. When even a mild frost occurs, premature fruit drop may occur; although the 'Hass' cultivar can tolerate temperatures down to −1 °C. Several cold-hardy varieties are planted in the region of Gainesville, Florida, which survive temperatures as low as −6.5 °C (20 °F) with only minor leaf damage. The trees also need well-aerated soils, ideally more than 1 m deep. However, Guatemalan varieties such as "MacArthur", "Rincon", or "Nabal" can withstand temperatures down to −1.6 °C (29 °F).
According to information published by the Water Footprint Network, it takes an average of approximately 70 litres (18 US gallons; 15 imperial gallons) of applied fresh ground or surface water, not including rainfall or natural moisture in the soil, to grow one avocado (283 L/kg [33.9 US gal/lb; 28.2 imp gal/lb]). However, the amount of water needed depends on where it is grown; for example, in the main avocado-growing region of Chile, about 320 L (85 US gal; 70 imp gal) of applied water are needed to grow one avocado (1,280 L/kg [153 US gal/lb; 128 imp gal/lb]).
Increasing demand and production of avocados may cause water shortages in some avocado production areas, such as the Mexican state of Michoacán. Avocados may also cause environmental and socioeconomic impacts in major production areas, illegal deforestation, and water disputes. Water requirements for growing avocados are three times higher than for apples, and 18 times higher than for tomatoes.
Commercial orchards produce an average of seven tonnes per hectare each year, with some orchards achieving 20 tonnes per hectare. Biennial bearing can be a problem, with heavy crops in one year being followed by poor yields the next.
Like the banana, the avocado is a climacteric fruit, which matures on the tree, but ripens off the tree. Avocados used in commerce are picked hard and green and kept in coolers at 3.3 to 5.6 °C (37.9 to 42.1 °F) until they reach their final destination. Avocados must be mature to ripen properly. Avocados that fall off the tree ripen on the ground. Generally, the fruit is picked once it reaches maturity; Mexican growers pick 'Hass' avocados when they have more than 23% dry matter, and other producing countries have similar standards. Once picked, avocados ripen in one to two weeks (depending on the cultivar) at room temperature (faster if stored with other fruits such as apples or bananas, because of the influence of ethylene gas). Some supermarkets sell ripened avocados which have been treated with synthetic ethylene to hasten ripening. The use of an ethylene gas "ripening room", which is now an industry standard, was pioneered in the 1980s by farmer Gil Henry of Escondido, California, in response to footage from a hidden supermarket camera which showed shoppers repeatedly squeezing hard, unripe avocados, putting them "back in the bin", and moving on without making a purchase. In some cases, avocados can be left on the tree for several months, which is an advantage to commercial growers who seek the greatest return for their crop, but if the fruit remains unpicked for too long, it falls to the ground.
The species is only partially able to self-pollinate because of dichogamy in its flowering. This limitation, added to the long juvenile period, makes the species difficult to breed. Most cultivars are propagated by grafting, having originated from random seedling plants or minor mutations derived from cultivars. Modern breeding programs tend to use isolation plots where the chances of cross-pollination are reduced. That is the case for programs at the University of California, Riverside, as well as the Volcani Centre and the Instituto de Investigaciones Agropecuarias in Chile.
The avocado is unusual in that the timing of the male and female flower phases differs among cultivars. The two flowering types are A and B. A-cultivar flowers open as female on the morning of the first day and close in late morning or early afternoon. Then they open as male in the afternoon of the second day. B varieties open as female on the afternoon of the first day, close in late afternoon and reopen as male the following morning.
Certain cultivars, such as the 'Hass', have a tendency to bear well only in alternate years. After a season with a low yield, due to factors such as cold (which the avocado does not tolerate well), the trees tend to produce abundantly the next season. In addition, due to environmental circumstances during some years, seedless avocados may appear on the trees. Known in the avocado industry as "cukes", they are usually discarded commercially due to their small size.
Avocados can be propagated by seed, taking roughly four to six years to bear fruit, although in some cases seedlings can take 10 years to come into bearing. The offspring is unlikely to be identical to the parent cultivar in fruit quality. Prime quality varieties are therefore propagated by grafting to rootstocks that are propagated by seed (seedling rootstocks) or by layering (clonal rootstocks). After about a year of growing in a greenhouse, the young rootstocks are ready to be grafted. Terminal and lateral grafting is normally used. The scion cultivar grows for another 6–12 months before the tree is ready to be sold. Clonal rootstocks are selected for tolerance of specific soil and disease conditions, such as poor soil aeration or resistance to the soil-borne disease (root rot) caused by Phytophthora cinnamomi. Advances in cloning techniques that can produce up to 500 new plants from a single millimetre of tree cutting have the potential to increase the availability of rootstocks.
Commercial avocado production is limited to a small fraction of the vast genetic diversity in the species. Conservation of this genetic diversity has relied largely on field collection, as avocado seeds often do not survive storage in seed banks. This is problematic, as field preservation of living cultivars is expensive, and habitat loss threatens wild cultivars. More recently, an alternate method of conservation has been developed based on cryopreservation of avocado somatic embryos with reliable methods for somatic embryogenesis and reconstitution into living trees.
The avocado tree can be grown domestically and used as a decorative houseplant. The pit germinates in normal soil conditions or partially submerged in a small glass (or container) of water. In the latter method, the pit sprouts in four to six weeks, at which time it is planted in standard houseplant potting soil. The plant normally grows large enough to be prunable; it does not bear fruit unless it has ample sunlight. Home gardeners can graft a branch from a fruit-bearing plant to speed maturity, which typically takes four to six years to bear fruit.
Avocado trees are vulnerable to bacterial, viral, fungal, and nutritional diseases (excesses and deficiencies of key minerals). Disease can affect all parts of the plant, causing spotting, rotting, cankers, pitting, and discoloration. The pyriform scale insect (Protopulvinaria pyriformis) is known from Australia, South Africa, Israel, Italy, France, Spain, Cuba, Florida, and Peru. It is normally found on avocado, and in Peru it is said to be the worst insect pest of the fruit. Certain cultivars of avocado seem more susceptible to attack by the scale than others.
Mexico is by far the world's largest avocado growing country, producing several times more than the second largest producer. In 2013, the total area dedicated to avocado production was 188,723 hectares (466,340 acres), and the harvest was 2.03 million tonnes in 2017. The states that produce the most are México, Morelos, Nayarit, Puebla, and Michoacan, accounting for 86% of the total. In Michoacán, the cultivation is complicated by the existence of drug cartels that extort protection fees from cultivators. They are reported to exact 2,000 Mexican pesos per hectare from avocado farmers and 1 to 3 pesos/kg of harvested fruit. It is such a problem that the phrase blood guacamole has been adopted to describe the social effects in Mexico of the vast worldwide demand for its fruits.
Avocados were introduced to California from Nicaragua in the early 1850s, when avocado trees imported from the Central American country were observed and reported growing near San Gabriel. The avocado has since become a successful cash crop. About 24,000 hectares (59,000 acres) – as of 2015, some 80% of United States avocado production – is located in Southern California.
Avocado is the official fruit of the state of California. Fallbrook, California, claims, without official recognition, the title of "Avocado Capital of the World" (also claimed by the town of Uruapan in Mexico), and both it and Carpinteria, California, host annual avocado festivals.
The California Avocado Commission and the California Avocado Society are the two major grower organizations and Calavo Growers is a major distributor.
'Hass' avocado production in Peru encompasses thousands of hectares in central and western Peru. Peru has now become the largest supplier of avocados imported to the European Union and the second largest supplier to Asia and the United States. The country's location near the equator and along the Pacific Ocean creates consistently mild temperatures all year.
'Hass' avocados from Peru are seasonally available to consumers from May through September and are promoted under the auspices of the Peruvian Avocado Commission, headquartered in Washington, D.C.
Chile has produced avocados for over 100 years with production increasing dramatically in the early 1980s due to global demand. New York magazine reported in 2015 that "Large avocado growers are draining the country's groundwater and rivers faster than they can replenish themselves." 88% of total production and 99% of exported avocados from Chile are Hass avocados. Avocados are a staple fruit in Chile with 30% of production destined for the domestic market. No import tariffs are imposed on Chilean avocados by China, the United States, or the European Union due to free trade agreements.
Other avocado cultivars include 'Spinks'. Historically attested varieties (which may or may not survive among horticulturists) include the 'Challenge', 'Dickinson', 'Kist', 'Queen', 'Rey', 'Royal', 'Sharpless', and 'Taft'.
A stoneless avocado, marketed as a "cocktail avocado", which does not contain a pit, is available on a limited basis. They are five to eight centimetres long; the whole fruit may be eaten, including the skin. It is produced from an unpollinated blossom in which the seed does not develop. Seedless avocados regularly appear on trees. Known in the avocado industry as "cukes", they are usually discarded commercially due to their small size.
In 2023, world production of avocados was 10.5 million tonnes, led by Mexico with 29% (3 million tonnes) of the total (table). Other major producers were Colombia, Dominican Republic, Peru, and Indonesia.
A 2024 market analysis indicated that avocado exports will increase over the next five years with as many as 30 countries producing avocados, possibly becoming the world's most traded fruit by 2030.
Some people have allergic reactions to avocado. There are two main forms of allergy: those with a tree-pollen allergy develop local symptoms in the mouth and throat shortly after eating avocado; the second, known as latex-fruit syndrome, is related to latex allergy and symptoms include generalised urticaria, abdominal pain, and vomiting and can sometimes be life-threatening.
Avocado leaves, bark, skin, or pit are documented to be harmful to animals; cats, dogs, cattle, goats, rabbits, rats, guinea pigs, birds, fish, and horses can be severely harmed or even killed when they consume them. The avocado fruit is poisonous to some birds, and the American Society for the Prevention of Cruelty to Animals (ASPCA) lists it as toxic to horses.
Avocado leaves contain a toxic fatty acid derivative, persin, which in sufficient quantity can cause colic in horses and without veterinary treatment, death. The symptoms include gastrointestinal irritation, vomiting, diarrhea, respiratory distress, congestion, fluid accumulation around the tissues of the heart, and even death. Birds also seem to be particularly sensitive to this toxic compound.
The leaves of the Guatemalan variety of P. americana are toxic to goats, sheep, and horses.
Raw avocado flesh is 73% water, 15% fat, 9% carbohydrates, and 2% protein (table). In a 100-gram reference amount, avocado supplies 670 kilojoules (160 kilocalories), and is a rich source (20% or more of the Daily Value, DV) of several B vitamins (such as 28% DV in pantothenic acid) and vitamin K (20% DV), with moderate contents (10–19% DV) of vitamin C, vitamin E, and potassium. Avocados also contain phytosterols and carotenoids, such as lutein and zeaxanthin.
Avocados have diverse fats. For a typical one:
Although costly to produce, nutrient-rich avocado oil has a multitude of uses for salads or cooking and in cosmetics and soap products.
In 2022, a prospective cohort study following 110,487 people for 30 years found that eating two servings of avocado per week reduced the risk of developing cardiovascular diseases by 16–22%. The study involved replacing half a daily serving of saturated fat sources, including margarine, butter, egg, yogurt, cheese, or processed meats, with an equivalent amount of avocado.
The fruit of horticultural cultivars has a markedly higher fat content than most other fruit, mostly monounsaturated fat, and as such serves as an important staple in the diet of consumers who have limited access to other fatty foods (high-fat meats and fish, dairy products). Having a high smoke point, avocado oil is expensive compared to common salad and cooking oils, and is mostly used for salads or dips.
A ripe avocado yields to gentle pressure when held in the palm of the hand and squeezed. The flesh is prone to enzymatic browning, quickly turning brown after exposure to air. To prevent this, lime or lemon juice can be added to avocados after peeling.
The fruit is not sweet, but distinctly and subtly flavored, with smooth texture. It is used in both savory and sweet dishes, though in many countries not for both. The avocado is common in vegetarian cuisine as a substitute for meats in sandwiches and salads because of its high fat content.
Generally, avocado is served raw, though some cultivars, including the common 'Hass', can be cooked for a short time without becoming bitter. The flesh of some avocados may be rendered inedible by heat. Prolonged cooking induces this chemical reaction in all cultivars.
It is used as the base for the Mexican dip known as guacamole, as well as a spread on corn tortillas or toast, served with spices. Avocado is a primary ingredient in avocado soup. Avocado slices are frequently added to hamburgers and tortas and is a key ingredient in California rolls and other makizushi ("maki", or rolled sushi).
In Mexico and Central America, avocados are served mixed with white rice, in soups, salads, or on the side of chicken and meat. They are also commonly added to pozole. In Peru, they are consumed with tequeños as mayonnaise, served as a side dish with parrillas, used in salads and sandwiches, or as a whole dish when filled with tuna, shrimp, or chicken. In Chile, it is used as a puree-like sauce with chicken, hamburgers, and hot dogs; and in slices for celery or lettuce salads. The Chilean version of Caesar salad contains large slices of mature avocado.
Avocados in savory dishes, often seen as exotic, are a relative novelty in Portuguese-speaking countries, such as Brazil, where the traditional preparation is mashed with sugar and lime, and eaten as a dessert or snack. This contrasts with Spanish-speaking countries such as Chile, Mexico, or Argentina, where the opposite is true and sweet preparations are rare. With the exception of the Philippines, a former Spanish colony where avocados are traditionally used in sweet preparations and savory uses are seen as exotic.
In the Philippines (where avocados were introduced from Mexico since before the 1700s), Brazil, Indonesia, Vietnam, and southern India (especially the coastal Kerala, Tamil Nadu and Karnataka region), avocados are frequently used for milkshakes and occasionally added to ice cream and other desserts. In Brazil, the Philippines Vietnam, and Indonesia, a dessert drink is made with sugar, milk or water, and pureed avocado. Chocolate syrup is sometimes added. In Morocco, a similar chilled avocado and milk drink is sweetened with confectioner's sugar and flavored with a touch of orange flower water.
In Ethiopia, avocados are made into juice by mixing them with sugar and milk or water, usually served with Vimto and a slice of lemon. It is also common to serve layered multiple fruit juices in a glass (locally called Spris) made of avocados, mangoes, bananas, guavas, and papayas. Avocados are also used to make salads. In Kenya and Nigeria, the avocado is often eaten as a fruit alone or mixed with other fruits in a fruit salad, or as part of a vegetable salad. In Ghana, they are often eaten alone on sliced bread as a sandwich. In Sri Lanka, their well-ripened flesh, thoroughly mashed or pureed with milk and kitul treacle (a liquid jaggery made from the sap of the inflorescence of jaggery palms), is a common dessert. In Haiti, they are often consumed with cassava or regular bread for breakfast.
In the United Kingdom, the avocado became available during the 1960s when introduced by Sainsbury's under the name 'avocado pear'. Much of the success of avocados in the UK is attributed to a long-running promotional campaign initiated by South African growers in 1995. In Australia and New Zealand, avocados are commonly served on sandwiches, sushi, toast, or with chicken.
In addition to the fruit, the leaves of Mexican avocados (Persea americana var. drymifolia) are used in some cuisines as a spice, with a flavor somewhat reminiscent of anise. They are sold both dried and fresh, toasted before use, and either crumbled or used whole, commonly in bean dishes.