AgroForestryTree Database
Elaeis guineensis
 Species identityEcology and distributionPropagation and managementFunctional usesPests and diseasesAdditional InfoBibliographyImages |
Species identity
TaxonomySynonym(s)
Common names
(Burmese) : si-htan, si-ohn
(Creole) : crocro, crocro guinee
(English) : African oil palm, guinea oil palm, oil palm, wild oil palm
(French) : corojo de Guinea, corossier, crocro, Crocro guinée, palmier a huile
(German) : Ölpalme, Steinfrüchte
(Luganda) : mubira, munazi
(Malay) : kelapa sawit
(Mandinka) : tango, tee, tego, tengo
(Spanish) : coroco, corojo de Guinea, corozo
(Swahili) : mchikichi, miwesi, mjenga
(Thai) : pan namman
(Trade name) : wild oil palm
(Vietnamese) : co dâu, dua dâu
Botanic description
Elaeis guineensis is a handsome tree reaching a height of 20 m or more at maturity. The trunk is characterized by persistent, spirally arranged leaf bases and bears a crown of 20-40 massive leaves. The root system consists of primaries and secondaries in the top 140 cm of soil. Leaves numerous, erect, spreading to drooping, long, reaching 3-5 m in adult trees; leaf stalks short with a broad base. Spiny, fibrous projections exist along the leaf margins from the leaf sheath, wearing away on old leaves to jagged spines. Leaf blades have numerous (100-160 pairs), of long leaflets with prominent midribs, tapered to a point; arranged in groups or singly along the midrib, arising sometimes in different planes. Male and female inflorescences occur on 1 plant; sometimes a single inforescence contains both male and female flowers. Inflorescences arise among the leaf bases in large, very dense clusters, with innumerable small flowers, enclosed in the bud stage in 2 large fibrous bracts, which finally become deciduous. Male flowers single or in pairs in recesses on the branchlets, each with 3 sepals, 3 petals with edges touching in bud, 6 stamens, and a small, sterile pistil. Female flowers subtended by 2-3 small bracts, with 3 sepals, 3 petals overlapping in bud in a ring of small, sterile stamens, and a 3-celled ovary with 3 spreading stigmas. Fruits borne in bunches. The average weight of each bunch is 23 kg, but a bunch may weigh up to 82 kg. A bunch contains between 200 and 2000 sessile ovoid drupes, 4 cm long and 2 cm broad, with pointed apex. The fruit coat colour varies from yellow to orange or nearly black. Four oil palm varieties have been distinguished on the basis of the fruit structure, especially the thickness of the endocarp: E. g. var. macrocarpa with 40-60% shell, E. guineensis var. dura with 20-40% shell, E. g. var. tenera with 5-20% shell and E. guineensis var. pisifera, a shelless form. The generic name comes from the Greek word ‘elaion’ (oil), referring to the oil extracted from the palm.
Ecology and distribution
History of cultivationE. guineensis, a native of forested portions of western and central Africa, particularly along rivers, has been spread across Africa by human migrations or intergroup exchange. It may have first been domesticated in Chad, taken to the Congo Basin and eastern Africa long before the arrival of Europeans, and to Sudan 5000 years ago. Africans probably took E. guineensis to Madagascar in the 10th century, the same time it is thought to have been established on the southern coast of Kenya, Pemba and Zanzibar. The Dutch introduced it to Southeast Asia. The Bogor Botanic Garden received some seedlings in 1848 from Amsterdam Botanical Gardens. The progeny from this introduction were planted initially between 1880 and 1900 as ornamentals on tobacco estates around Deli and Medan and laid the foundation for the oil palm industry in Southeast Asia. The Singapore Botanic Garden received seeds from Java in 1870, and this helped to diffuse E. guineensis throughout Malaysia and into Sumatra. As markets for oil palm expanded in Europe, the exotic E. guineensis was cultivated on plantation scale starting in 1911. The 1st plantations were established in Malaysia in 1917. In India it was first introduced in 1834 in the botanic garden in Calcutta, and trial plantings were started in 1930 in Kerala. The 1st commercial plantings were started in Kerala in the 1970s. Slave traders took E. guineensis to the New World, but until recently it has not been cultivated to any extent except in Bahia, Brazil.
Natural Habitat
It is difficult to determine the natural habitat of the oil palm because, while it does not grow in primeval forest, it flourishes in habitats where forests have been cleared. It requires a relatively open area to grow and reproduce itself and thrives best when soil moisture is maintained. Normally, E. guineensis occurs in disturbed forests and along rivers and streams, both in its native range in West Africa and in some introduced areas. It is a succession species favoured by slash and burn, and its gene pool has expanded as farmers clear land and create more open habitat for the germination of its seeds.
Geographic distribution
Native : Cameroon, Cote d'Ivoire, Democratic Republic of Congo, Ghana, Guinea, Sierra Leone, Uganda
Exotic : China, Colombia, Congo, Costa Rica, Ecuador, Honduras, India, Indonesia, Kenya, Madagascar, Malaysia, Nigeria, Papua New Guinea, Philippines, Singapore, Solomon Islands, Sri Lanka, Tanzania, Togo, Venezuela, Zanzibar
Biophysical limitsAltitude: Up to 900 m, Mean annual temperature: 27-35 deg. C, Mean annual rainfall: 2000-3000 mm Soil type: It has a fibrous root system and benefits from deep soils that are fertile, free from iron concretions and well drained. It also tolerates a fair range of soil pH (4-6), although neutral soils are favourable.
Reproductive Biology
Male and female flowers are borne on the same plant but open at different times, so that cross-pollination is necessary. A male inflorescence contains 700-1200 flowers and may yield 80 g of pollen over a 5-day period. The female flower is larger and receptive to pollen for 36-48 hours. Honeybees are attracted by the pollen scented like anise seed, which they collect as they gather nectar. It has not been established whether the bees contribute to pollination. However, The weevil Elaeidobius kamerunicus has been found to be a successful pollinator. Fruit development commences immediately after fertilization. Black vultures (Coragypt atratus) feed avidly on E. guineensis and are involved in its dispersal.
Propagation and management
Propagation methodsE. guineensis is normally seed propagated. As seeds naturally germinate slowly, pretreatment is necessary. The seeds are placed in intact 500-gauge polythene bags arranged on wooden boxes in a germinator at 39-40 deg. C for 75-80 days. They are then soaked in cold water for 3 days, changing water every 24 hours. The seeds are drained and dried under shade and kept at room temperature. They are examined every 2 weeks for germination and drying. Drying seeds are sprayed with water; germinated seeds are picked for potting. This treatment gives an 80% germination rate.Tree Management
Initial spacing is normally 9 m in a triangular arrangement, giving 140 trees/ha. The individual trees are fenced with wire netting to protect them from attack by rodents and grass cutters that eat the heart of young palms during the 1st few years. Mulching to conserve moisture in the dry season is necessary. The lower senescent leaves should be removed and burnt.
Germplasm Management
Seed storage behaviour is intermediate. Storage temperatures of 5 deg. C are said to damage seed viability in moist storage. Kernels were safely dried to 4.4% mc when set to germinate in vitro. However, hermetic storage of intact kernels at -18 deg. C or -196 deg. C with moisture content between 20.9% and 4.4% resulted in a loss in viability by about 13%; no loss in viability after 8 months subsequent storage in liquid nitrogen; no loss in viability occurred after 4 months hermetic storage at either 10 deg. C or 30 deg. C with 19.4-5.2% mc; 50-70% of excised embryos survived desiccation to 10.4% mc by slow drying, and no loss in viability in subsequent cryostorage overnight; seeds tolerated desiccation to 10-6% mc; depending on seed lot, no loss in viability after 12 months of hermetic storage at 15 deg. C, but complete loss in viability occurred at 0 deg. C and -20 deg. C; there are about 230 seeds/kg.
Functional uses
ProductsFood: Palm oil is popular in West Africa and Malaysia for cooking. It is now imported by India to meet local shortages in edible oil, being cheaper than many other vegetable oils. In West Africa, palm oil is often added directly to bring richness to soups and sauces. Addition of oil to cereal preparations greatly increases their calorific density, which is particularly advantageous for young children. Palm oil is also used as frying oil in the preparation of snacks such as bean cakes and fried plantain. Its 10% linoleic acid content makes it an excellent source of carotene. This is important in reducing incidence of vitamin A deficiency and the occurrence of nutritional blindness. Oil palm also provides heart-of-palm. Fodder: Pressed cake is used as cattle feed. Apiculture: The juice from fermenting fruit is collected by bees. The honey is dark amber with an astringent flavour. Fuel: It is technically possible to produce from palm oil either carbohydrates for conversion to alcohol or a methanolizable oil as a diesel substitute. In Togo, the pressed fruits are dried and fashioned into cakes for cooking fuel. Lipids: Palm kernel oil contains about 50% oil. This oil is used in hard water soaps, the manufacture of glycerin, shampoos and candles. The better grades are used in manufacturing margarine. Alcohol: Palm wine is the delicious wine obtained by tapping the base of the immature inflorescence of the oil palm. Freshly tapped, undiluted and chilled, palm wine is pleasant to drink and is very high in yeast content. The sale of palm wine is considered more profitable than the sale of the fruits and oil.Services
Reclamation: Oil palm is a good crop for rehabilitating degraded areas. In Sumatra it has successfully been established on abandoned farmlands taken over by Imperata cylindrica. Shade or shelter: E. guineensis shade is lighter than that of other plantation crops such as rubber or cocoa and is suitable for substantial quantities of undergrowth, attracting livestock. Attention has been given to raising livestock in oil palm plantations as a subsidiary source of income. Palm fronds are useful for thatch. Soil improver: The potash-rich residue from boilers is routinely recycled onto plantations to help enrich the soils for instance in Malaysia. Labour and transportation costs may discourage such recycling. Ornamental: E. guineensis has been planted as an ornamental on tobacco estates around Deli and Medan in Sumatra. Intercropping: Coffee and cocoa are small trees that can be planted among E. guineensis trees. Shading with E. guineensis presents certain difficulties, because while cocoa benefits from greater shade when it is young, the shade that the palm provides becomes increasingly undesirable as the cocoa plantation matures.
Pests and diseasesE. guineensis is attacked by nematodes, slugs, snails, mites, insects, birds and mammals. Mammals include rats, wild pigs, monkeys and elephants, which damage seedlings and fruits. Birds include the long-tailed parakeet, the American black vulture, the house crow and the large-billed crow. The birds carry away fruit from the bunch and scatter it half-eaten. Only 1 nematode, Rhadinaphelenchus cocophilus, has been responsible for a serious diseased condition, red-ring disease. Damaging insects include the oil palm bunch moth and the West African oil palm leaf miner. Diseases have become prevalent in areas where E. guineensis is cultivated on a plantation scale. Diseases of particular concern include fusarium wilt (caused by Fusarium oxysporum) and bacterial bud rot (in Democratic Republic of Congo), dry basal rot, caused by Ceratocystis paradoxa (in Nigeria), ganoderma trunk rot and crown disease in Asia; and spear rot in the American tropics. Spear rot has emerged as a major threat to E. guineensis production in Latin America.
Bibliography
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