Common Name: Avocado

General Information

Avocado is a large, spreading, evergreen tree with an irregular, dense crown, that can vary widely in height according to variety. Grafted trees generally tend to be 8 - 10 metres tall, but grown on their own roots they can be up to 20 metres tall[]. The bole can be around 45cm in diameter, it usually branches from low down[, ].
The fruit is widely appreciated and found for sale in countries all around the world. The tree is also valued for the oil it yields and for its many medicinal applications. The tree is extensively cultivated in tropical and sub-tropical regions[, ].

Known Hazards

The unripe fruit is poisonous[].
The ground up seed is mixed with cheese and used as a poisonous bait to kill rats and mice[].

Botanical References

Range

Central America - Mexico.

Habitat

Humid lowland forests on limestone formations[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Evergreen Tree
Height	15.00 m
Growth Rate	Fast
Pollinators	Bees, Insects
Self-fertile	No
Cultivation Status	Cultivated, Wild

Cultivation Details

Different forms of the plant can succeed in a range of climates, ranging from subtropical with occasional frosts to lowland and highland tropics, where it can be grown at elevations as high as 2,800 metres. It grows best in areas where annual daytime temperatures are within the range 14 - 40°c, but can tolerate 10 - 45°c[]. When dormant, the plant can survive temperatures down to about -4°c, but young growth can be severely damaged at -1°c[]. It prefers a mean annual rainfall in the range 500 - 2,000mm, but tolerates 300 - 2,500mm[].
Prefers a rich, neutral to alkaline soil and a position in full sun[]. Succeeds on all kinds of soil[]. Requires a well-drained soil, the plant is intolerant of water-logging[, ]. West Indian rootstocks are fairly tolerant of saline conditions, though other forms are intolerant[]. Prefers a pH in the range 5 - 5.8, tolerating 4.5 - 7[]. Requires a position sheltered from strong winds[].
Seedlings take 6- 8 years to produce fruit, whilst grafts can start fruiting in their second year[].
Yields of 15 tonnes per hectare have been recorded, but averages are about half that figure[].
Mature fruit can be left hanging on the tree for weeks without damage[].
The three main races of Avocado are as follows. There are many named varieties of each race:-
Mexican. This is the hardiest form, succeeding in subtropical climates and not well adapted to lowland tropical conditions[]. It can withstand short periods when temperatures drop as low as -6°c[]. The optimum temperature for growth is between 14 - 25°c[]. It has the highest oil content, over 20% and up to 30%[].
Guatemalan. This form is semitropical. It can withstand short periods when temperatures drop as low as -4°c[]. The optimum temperature for growth is between 15 - 28°c[]. It has a medium oil content generally between 10 - 20%[].
West Indian. This form is wholly tropical and grows well in a lowland tropical climate[]. It can grow in a temperature range of 12 - 40°c, though the optimum is between 24 - 32°c[]. It has the lowest oil content, generally below 10%, down to around 3%[].
Although the flowers are hermaphrodite, the male organ produces pollen when the females are not receptive and so each tree is functionally self-sterile. Therefore at least two different trees are required for pollination[].
Each avocado flower opens twice. The female part ripens first, then the flower closes to open many hours later in the male stage[]. In the Mexican form, this gap is more than 24 hours, from morning to the next afternoon, whilst in the Guatemalan it is less than 24 hours[].

Edible Uses

Fruit - raw[]. The flesh has a buttery texture and a mild, oily flavour. It is commonly eaten raw and may also be used as a sandwich spread, in ice creams etc[]. The pear-shaped fruit is up to 12cm long[].

A non-drying oil obtained from the fruit has a mild, pleasant taste[, ]. It is used as a salad dressing, especially with strong tasting leaves such as chicory, rocket and watercress[].

A tea can be made from the leaves[].

Toasted leaves are used as a flavouring in stews and bean dishes[].

Medicinal

The avocado has long been used medicinally, with most parts of the plant being employed[]. There has been some research into the medicinal properties of the plant that support traditional uses.
Research has shown that there is anti-cancerous activity in extracts of the leaves and fresh shoots[].
Leaf extracts have shown antihypertensive activity[]
The leaf and seed contain cyanide[].
The oil from the seeds contains steroids that are used for pharmaceuticals[].
The seed extract has an erythroagglutinating property[].
The fruit contains reductase and transferase enzymes[].

The leaves are astringent, carminative, antitussive, emmenagogue and hypotensive[, ]. An oral infusion of the leaves is used to treat dysentery[]. It is also used for relieving coughs, lowering blood pressure, treating liver obstructions, promoting menstrual flow and for clearing high uric acid levels in the body which could lead to gout[, ]. Combined with Tripogandra serrulata, they are used as a remedy for biliousness[].

The bark is astringent, carminative, antitussive and emmenagogue[]. It is used in the treatment of diarrhoea[].

The fruit pulp is emollient, carminative and helps lower blood cholesterol levels[]. The mashed fruit pulp is a nourishing food that is considered to have aphrodisiac properties[]. From unripe fruit used to induce abortion.
Used externally, the pulp is cooling and soothing to the skin - it is applied to suppurating wounds and to the scalp to promote hair growth[].

The skin of the fruit has anthelmintic properties and is used traditionally for expelling worms[, , ].

The seed is ground and made into an ointment used to treat various skin afflictions, such as scabies, purulent wounds, lesions of the scalp and dandruff[].

Oil extracted from the seeds has astringent properties[].

Other Uses

The pulp and the seeds contain fatty acids, such as oleic, lanolic, palmitic, stearic, linoleic, capric and miristic acid which constitutes 80% of the fruits fatty content. The non-drying oil extracted from the seed is used by the cosmetic industry in soaps and skin moisturizer products[].

The fresh fruit pulp is massaged into the hair and scalp as a vitamin-rich hair tonic and restorer[].

A reddish-brown dye obtained from the seed is used for marking clothes[, ].

Watery extracts of the avocado leaves contain a yellowish-green essential oil[].

The ground-up seed mixed with cheese is used as a rat and mouse poison[].

The heartwood is light brown; the sapwood is whitish. The wood is moderately soft, heavy, brittle, but not durable. It is brittle, and susceptible to termite attack[]. It has been used for house building (especially for house posts), light construction, furniture, cabinet making, agricultural implements, carving, sculptures, musical instruments, paddles, small articles like pen and brush holders, and novelties. It also yields a good-quality veneer and plywood[, , ]. More popular for its fruits the wood of avocado is seldom used[].

Propagation

Seed - sown fresh it can germinate in about a month - this can be reduced to about 17 days if the seed coat is removed[]. A regimen of 25°c daytime temperature and 15°cC night-time produces germinates within 3 weeks of sowing fresh seed[]. The seedlings grow quickly and continuously under warm, moist conditions[].

Add a Comment:

If you have any useful information about this plant, please leave a comment. Comments have to be approved before they are shown here.

Name:

Email(Private):

Message:

Captcha: 6 add another 6 is?