Elaeis guineensis Jacq.
Syn.: Elaeis melanococca J. Gaertn.
African oil palm
Source: James A. Duke. 1983. Handbook of Energy Crops. unpublished.
- Folk Medicine
- Yields and Economics
- Biotic Factors
Two kinds of oil are obtained from this palm, Palm Oil and Palm Kernel Oil.
Palm oil is extracted from the fleshy mesocarp of the fruit which contains
45-55% oil which varies from light yellow to orange-red in color, and melts
from 25° to 50°C. For edible fat manufacture, the oil is bleached. Palm
oil contains saturated palmitic acid, oleic acid and linoleic acid, giving it a
higher unsaturated acid content than palm kernel or coconut oils. Palm oil is
used for manufacture of soaps and candles, and more recently, in manufacture of
margarine and cooking fats. Palm oil used extensively in tin plate industry,
protecting cleaned iron surfaces before the tin is applied. Oil also used as
lubricant, in textile and rubber industries. Palm kernel oil is extracted from
the kernel of endosperm, and contains about 50% oil. Similar to coconut oil,
with high content of saturated acids, mainly lauric, it is solid at normal
temperatures in temperate areas, and is nearly colorless, varying from white to
slightly yellow. This non-drying oil is used in edible fats, in making ice
cream and mayonnaise, in baked goods and confectioneries, and in the
manufacture of soaps and detergents. Press cake, after extraction of oil from
the kernels, used as livestock feed, containing 5-8% oil. Palm wine made from
the sap obtained by tapping the male inflorescence. The sap contains about 4.3
g/100 ml of sucrose and 3.4 g/100 ml of glucose. The sap ferments quickly, and
is an important source of Vitamin B complex in diet of people of West Africa.
A mean annual yield per hectare of 150 palms of 4,000 liters is obtained, and
is double in value to the oil and kernels from same number of palms. Central
shoot or cabbage is edible. Leaves used for thatching; petioles and rachices
for fencing and for protecting the tops of retid walls. Refuse after stripping
the bunches used for mulching and manuring; ash sometimes used in soap-making.
According to Hartwell (1967-1971), the oil is used as a liniment for indolent
tumors. Reported to be anodyne, antidotal, aphrodisiac, diuretic, and
vulnerary, oil palm is a folk remedy for cancer, headaches, and rheumatism
(Duke and Wain, 1981).
As oil is rich in carotene, it can be used in place of cod liver oil for
correcting Vitamin A deficiency. Per 100 g, the fruit is reported to contain
540 calories, 26.2 g H2O, 1.9 g protein, 58.4 g fat, 12.5 g total carbohydrate,
3.2 g fiber, 1.0 g ash, 82 mg Ca, 47 mg P, 4.5 mg Fe, 42,420 ug ß-carotene
equivalent, 0.20 mg thiamin, 0.10 mg riboflavin, 1.4 mg niacin, and 12 mg
ascorbic acid. The oil contains, per 100 g, 878 calories, 0.5% H2O, 0.0%
protein, 99.1% fat, 0.4 g total carbohydrate, 7 mg Ca, 8 mg P, 5.5 mg Fe,
27,280 ug ß-carotene equivalent, 0.03 mg riboflavin, and a trace of
thiamine. The fatty composition of the oil is 0.5-5.9% myristic, 32.3-47.0
palmitic, 1.0-8.5 stearic, 39.8-52.4 oleic, and 2.0-11.3 linoleic. The
component glycerides are oleodipalmitins (45%), palmitodioleins (30%),
oleopalmatostearins (10%), linoleodioleins (6-8%), and fully saturated
glycerides, tripalmatin and diapalmitostearin (6-8%).
Tall palm, 8.3-20 m tall, erect, heavy, trunks ringed; monoecious, male and
female flowers in separate clusters, but on same tree; trunk to 20 m tall,
usually less, 30 cm in diameter, leaf-bases adhere; petioles 1.3-2.3 m long,
12.5-20 cm wide, saw-toothed, broadened at base, fibrous, green; blade pinnate,
3.3-5 m long, with 100-150 pairs of leaflets; leaflets 60-120 cm long, 3.5-5 cm
broad; central nerve very strong, especially at base, green on both surfaces;
flower-stalks from lower leaf-axils, 10-30 cm long and broad; male flowers on
short furry branches 10-15 cm long, set close to trunk on short pedicels;
female flowers and consequently fruits in large clusters of 200-300, close to
trunk on short heavy pedicels, each fruit plum-like, ovoid-oblong to 3.5 cm
long and about 2 cm wide, black when ripe, red at base, with thick ivory-white
flesh and small cavity in center; nuts encased in a fibrous covering which
contains the oil. About 5 female inflorescences are produced per year; each
inflorescence weighing about 8 kg, the fruits weighing about 3.5 g each.
Reported from the African Center of Diversity, the African oil palm or cvs
thereof is reported to tolerate high pH, laterite, low pH, savanna, virus, and
waterlogging (Duke, 1978). Cultivars are said not to occur (Reed, 1976), but
Ehganullah (1972) published on oil palm cultivars. African Oil Palm is
monoecious and cross-pollinated, and individual palms are very heterozygous.
Three varieties are distinguished: those with orange nuts which have the finest
oil but small kernels; red or black nut varieties have less oil, but larger
kernels. Sometimes oil palms are classified according to the fruit structure:
Dura, with shell or endocarp 2-8 mm thick, about 25-55% of weight of fruit;
medium mesocarp of 35-55% by weight, but up to 65% in the Deli Palms; kernels
large, 7-20% of weight of fruit; the most important type in West Africa; the
macrocarya form with shells 6-8 mm thick forms a large proportion of
crop in western Nigeria and Sierra Leone. Tenera, with thin shells,
0.5-3 mm thick, 1-32% of weight of fruit; medium to high mesocarp 60-95% of
weight of fruit; kernels 3-15% of fruit; larger number of bunches than Dura,
but lower mean bunch weight and lower fruit to bunch ratio. Pisifera,
shell-less, with small kernels in fertile fruits, fruits often rotting
prematurely; fruit to bunch ratio low; infertile palms show strong vegetative
growth, but of little commercial value, but has now become of greatest
importance in breeding commercial palms. Deli Palm (Dura type) originated in
Sumatra and Malaya, gives high yields in the Far East, but not so good in West
Africa. Dumpy Oil Palm, discovered in Malaya among Deli Palms, is low-growing
and thick stemmed. Breeding and selection of oil palm has been aimed at
production of maximum quantity of palm oil and kernels per hectare, and
resistance to disease. Recently, much attention has been directed at
cross-breeding with E. oleifera for short-trunk hybrids, thus making
harvesting easier. Zeven (1972) elucidates the center of diversity, and
discusses the interactions of some important oil palm genes.(2n = 32,36)
Center of origin of the oil palm is in the tropical rain forest region of West
Africa in a region about 200-300 km wide along coastal belt from Liberia to
Angola. The palm has spread from 16°N latitude in Senegal to 15°S in
Angola and eastwards to the Indian Ocean, Zanzibar and Malagasy. Now
introduced and cultivated throughout the tropics between 16°N and S
latitudes. Sometimes grown as an ornamental, as in southern Florida.
Occurs wild in riverine forests or in freshwater swamps. It cannot thrive in
primeval forests and does not regenerate in high secondary forests. Requires
adequate light and soil moisture, can tolerate temporary flooding or a
fluctuating water table, as might be found along rivers. Ranges ecologically
from savanna to rain forest. It is slightly hardier than coconut. Native to
areas with 1,780 to 2,280 mm rainfall per year. Best developed on lowlands,
with 2-4 month dry period. Mean maximum temperature of 30-32°C and mean
minimum of 21-24°C provide suitable range. Seedling growth arrested below
15°C. Grows and thrives on wide range of tropical soils, provided they have
adequate water supply. Waterlogged, highly lateritic, extremely sandy, stony
or peaty soils should be avoided. Coastal marine alluvial clays, soils of
volcanic origin, acid sands and other coastal alluviums are used. Soils with
pH of 4-6 are most often used. Ranging from Subtropical Dry (without frost)
through Tropical Dry to Wet Forest Life Zones, oil palm is reported to tolerate
annual precipitation of 6.4 to 42.6 dm (mean of 27 cases = 22.7), annual
temperature of 18.7 to 27.4°C (mean of 27 cases = 24.8), and pH of 4.0 to
8.0 (mean of 22 cases = 5.7) (Duke, 1978, 1979).
In wild areas of West Africa the forest is often cleared to let 75 to 150 palms
stand per hectare; this yields about 2.5 MT of bunches per hectare per year.
Normally oil palms are propagated by seed. Seed germination and seedling
establishment are difficult. Temperature of 35°.C stimulates germination in
thin shelled varieties. Thick-walled varieties require higher temperatures.
Seedlings are outplanted at about 18 months. In some places, seeds are
harvested from the wild, but plantation culture is proving much more rewarding.
In a plantation, trees are spaced 9 x 9 m, a 410-ha plantation would have about
50,000 trees, each averaging 5 bunches of fruit, each averaging 1 kg oil to
yield a total of 250,000 kg oil for the 410 ha. Vegetative propagation is not
feasible as tree has only one growing point. Because oil palm is monoecious,
cross-pollination is general and the value of parent plants is determined by
the performance of the progeny produced in such crosses. Bunch-yield and oil
and kernel content of the bunches are used as criteria for selecting individual
palms for breeding. Controlled pollination must be maintained when breeding
from selected plants. Seed to be used for propagation should be harvested
ripe. Best germination results by placing seeds about 0.6 cm deep in sand
flats and covering them with sawdust. Flats kept fully exposed to sun and kept
moist. In warm climates, 50% of seed will germinate in 8 weeks; in other areas
it may take from 64-146 days. Sometimes the hard shell is ground down, or
seeds are soaked in hot water for 2 weeks, or both, before planting. Plants
grow slowly at first, being 6-8 years old before the pinnate leaves become
normal size. When planting seedlings out in fields or forest, holes are dug,
and area about 1 m around them cleared. Young plants should be transplanted at
beginning of rainy season. In areas where there is no distinct dry season, as
in Malaya, planting out may be done the year round, but is usually done during
months with the highest rainfall. Seedlings or young plants, 12-18 months old,
should be moved with a substantial ball of earth. Ammonium sulfate and sulfate
or muriate of potash at rate of 227 g per palm should be applied in a ring
about the plant at time of planting. Where magnesium may be deficient in the
soil, 227 g Epsom salts or kieserite should be applied also. In many areas oil
palms are intercropped with food plants, as maize, yams, bananas, cassava or
cocoyams. In Africa, intercropping for up to 3 years has helped to produce
early palm yields. Cover-crops are often planted, as mixtures of
Calopogonium mucunoides, Centrosema pubescens and Pueraria
phaseoloides, planted in proportion of 2:2:1 with seed rate of 5.5 kg/ha.
Natural covers and planted cover crops can be controlled by slashing. Nitrogen
dressings are important in early years. Chlorosis often occurs in nursery beds
and in first few years after planting out. Adequate manure should be applied
in these early years. When nitrogen fertilizers, as sulfate of ammonium are
used, 0.22 kg per palm in the planting year and 0.45 kg per palm per year until
age 4, should be sufficient. Potassium, magnesium, and trace element
requirements should be determined by soil test and the proper fertilizer
applied, according to the region, soil type and degree of deficiency.
First fruit bunches ripen in 3-4 years after planting in the field, but these
may be small and of poor quality. Often these are eliminated by removal of the
early female inflorescences. Bunches ripen 5-6 months after pollination.
Bunches should be harvested at correct degree of ripeness, as under-ripe fruits
have low oil concentration and over-ripe fruits have high fatty acid content.
Harvesting is usually done once a week. In Africa, bunches of semi-wild trees
are harvested with a cutlass, and tall palms are climbed by means of ladders
and ropes. For the first few years of harvesting, bunches are cut with a steel
chisel with a wooden handle about 90 cm long, allowing the peduncles to be cut
without injuring the subtending leaf. Usually thereafter, an axe is used, or a
curved knife attached to a bamboo pole. A man can harvest 100-150 bunches per
day. Bunches are carried to transport centers and from there to the mill for
According to the Wealth of India, the oil yield of oil palm is higher than that
of any other oilseed crop producing 2.5 MT oil per ha per year, with 5 MT
recorded. Yields of semi-wild palms vary widely, usually ranging from 1.2 to 5
MT of bunches per hectare per year. One MT of bunches yields about 80 kg oil
by local soft oil extraction, or 180 kg by hydraulic handpress. Estate yields
in Africa vary from 7.5-15 MT bunches per hectare per year; in Sumatra and
Malaya, 15-25 MT, with some fields producing 30-38 MT. Estate palm oil
extraction yield rates vary accordingly: Dura, 15-16% oil per bunch;
Deli Dura, 16-18%; Tenera, 20-22%. Kernel extraction yields vary
from 3.5-5% or more. Palm oil is one of the world's important vegetable oils.
United States imported nearly 90 million kg in 1966, more than half of it as
kernel oil. Recently palm oil commanded $.31 per kg, indicating potential
yields of about $1400 per ha. In 1968 world producing countries exported about
544,000 long tons of oil and 420,000 long tons of kernels. Main producing
countries, in order of production, are Nigeria, Congo, Sierra Leone, Ghana,
Indonesia, and Malaysia. United Kingdom is the largest importer of oil palm
products, importing about 180,000 T of palm oil and 243,000 T of palm kernels
annually. Japan, Eastern European and Middle East countries also import
considerable quantities of palm oil and kernels. Some palm kernel oil
extraction is now being done in the palm oil producing countries. Previously,
most of the kernels had been exported, and the oil extracted in the importing
Bunch yields may attain 22,000 kg/ha; of which only about 10% is oil,
indicating oil yields of only 2,200 kg/ha. Higher yields are attainable.
Corley (1981) suggests plantation yields of 2-6 MT/ha mesocarp oil,
experimentally up to 8.5 MT/ha. Hodge (1975), citing oil yields of 2,790 kg/ha
suggests that this is the most efficient oil making plant species. The
seasonal maximum total biomass reported for oil palm is 220 MT wet weight.
When replanting occurs, over 40 MT/ha (dry weight) of palm trunks are
available, conceivably for energy production, after the 70% moisture from the
wet material has been expelled (Corley, 1981). Although annual productivity
may approach 37 MT DM/ha, mean productivity during the dry season is 10
g/m2/day (Westlake, 1963). Averaged over the year, oilpalm in
Malaysia showed a growth rate of 8 g/m2/day for an annual phytomass
production of 29.4 MT/ha (Boardman, 1980). Fresh fruit bunch yields have been
increased elsewhere by 2 MT/ha intercropping with appropriate legumes. Estate
yields in Africa are 7-15 MT bunches per year, with oil yields of 800-1800
kg/ha, and residues of yields of ca 6-13 MT. It is probable that older leaves,
leaf stalks, etc., could be harvested with biomass yield of 1-5 MT/ha. Based
on energetic equivalents of total biomass produced, up to 60 barrels of oil per
hectare could be obtained from this species. An energy evaluation of all the
wastes from the palm oil fruit was made and it revealed that this can satisfy
ca 17% of Malaysia's energy requirements. Palm oil could satisfy 20% more
(Keong, 1981). An alcoholic wine can be made from the sap of the male spikes,
150 trees yielding about 4,000 laters of palm wine per hectare, per year. Most
incredible, and surely worthy of energetic interest is Gaydou et al's (1982)
suggestion that the oil palm can yield twice as much energetically as sugar
cane, at least based on the Malagasy calculations. I am told that palmoil is
already flowing in Malaysian pipelines, but that the palm oil industry is the
most serious polluter in Malaysia. Barker and Worgan (1981) report utilization
of the effluents. Biomass yields of ca 50 g/100g OM were obtained containing
40% CP with BOD reductions of 85% and COD reductions of 75-80% in batch
culture. Supplementation with an inorganic N source was necessary.
Many fungi attack oil palms, but the most serious ones are the following: Blast
(Pythium splendens, followed by Rhizoctonia lamellifera), Freckle
(Cercospora elaeidis), Anthracnose (Botryodiplodia palmarum,
Melanconium elaeidis, Glomerella cingulata), Seedling blight (Curvularia
eragrostidis), Yellow patch and Vascular wilt (Fusarium oxysporum),
Basal rot of trunk (Ceratocystis paradoxa, imp. stage of
Thielaviopsis paradoxa), other trunk rots (Ganoderma spp.,
Armillaria mellea); Crown disease, rotting of fruit (Marasmius
palmivorus). Spear rot or bud rot is caused by the bacterium
Erwinia sp., which has devastated entire areas in S. Congo. The
following nematodes have been isolated from oil palms: Aphelenchus avenae,
Helicotylenchus pseudorobustus, H. microcephalus Hoplolaimus pararobustus,
H. sp., Meloidogyne sp., Rhadinaphelenchus cocophilus
(serious in Venezuela), and Scutellonema clathrocaudatus (Golden,
p.c., 1984). The major pests of oil palm in various parts of the world are the
following: Palm weevils (Rhynchophorus phoenicis, R. palmarum, R.
ferrugineus), Rhinoceros beetles (Oryctes rhinoceros, O. boas, O.
monoceros, O. owariensis), Weevils (Strategus aloeus, Temnoschoita
quadripustulata), Leaf-miners (Coelaenomenodera elaeidis, Hispolepis
elaeidis, Alurunus humeralis), Slug caterpillar (Parasa
viridissima), Nettle caterpillar (Setora nitens), Bagworms
(Cremastophysche pendula, Mahasena corbetti, Metisa plana). Rodents may
cause damage to seedlings and fruiting palms; some birds also cause damage in
Complete list of references for Duke, Handbook of Energy Crops
- Barker, T.W. and Worgan, J. T. 1981. The utilization of palm oil processing
effluents as substrates for microbial protein production by the fungus
Aspergillus oryzae. Eur. J. Appl. Microbio. & Biotechn.
- Boardman, N.K. 1980. Energy from the biological conversion of solar energy.
Phil. Trans. R. Soc. London A 295:477-489.
- Corley, R.H.V. 1981. Oil palm. p. 397-403. In: McClure, T.A. and Lipinsky, E.S.
(eds.), CRC handbook of biosolar resources. vol. 11. Resource materials. CRC
Press, Inc., Boca Raton, FL.
- Duke, J.A. 1978. The quest for tolerant germplasm. p. 1-61. In: ASA Special
Symposium 32, Crop tolerance to suboptimal land conditions. Am. Soc. Agron.
- Duke, J.A. 1979. Ecosystematic data on economic plants. Quart. J. Crude Drug
- Duke, J.A. and Wain, K.K. 1981. Medicinal plants of the world. Computer index
with more than 85,000 entries. 3 vols.
- Ehganullah (1972)
- Gaydou, A.M., Menet, L., Ravelojaona, G., and Geneste, P. 1982. Vegetable
energy sources in Madagascar: ethyl alcohol and oil seeds (French). Oleagineux
- Hartwell, J.L. 1967-1971. Plants used against cancer. A survey. Lloydia 30-34.
- Hodge, W.H. 1975. Oil-producing palms of the world: a review. Principes
- Keong, W.K. 1981. Soft energy from palm oil and its wastes. Agr. Wastes
3(3):191-200. Dept. Envir. Sci., Vinversiti Pertanian Malaysia, Serdang,
- Reed, C.F. 1976. Information summaries on 1000 economic plants. Typescripts
submitted to the USDA.
- Westlake, D.F. 1963. Comparisons of plant productivity. Biol. Rev. 38:385-425.
- Zeven, A.C. 1972. The partial and complete domestication of the oil palm
(Elaeis guineensis). Econ. Bot. 26(3):274-280.
last update July 10, 1996