Oil palm is an oil-producing tropical perennial crop. Elaeis guineensis is a single-stemmed palm which bears a single vegetative shoot, which is continuously active producing a new leaf every two weeks in mature palms.
Palm trees may grow up to sixty feet and more in height. The trunks of young and mature trees are wrapped in fronds which give them a rather rough appearance. The older trees have smoother trunks apart from the scars left by the fronds which have withered and fallen off.
Oil palm is a monoecious crop as it bears both male and female flowers on the same tree. Pollination of the palms had been done manually up to the 1970s using especially designed bellows attached to a long pipe to blow pollen onto female flowers.After importation of oil palms to Malaysia, New Guinea and the Solomon Islands, the palms bore fruit only when manually dusted. In 1977, an entomologist from the
Commonwealth Institute of Biological Control was put in charge by Unilever to investigate the case. He discovered that, contrary to long held belief, the plants were not wind pollinated, but in fact insects did the job in Africa, their country of origin. In particular weevils of the genus Elaeidobius had developed a symbiotic relationship with the palm and were the principal agents involved. These were not present in South East. The most common one is Elaeidobius kamerunicus (african oil palm weevil), which was introduced in Asia, South and Central America. Its introduction led to an increase in yields of more than 35%.
African Oil Palm Weevil
Each tree produces compact bunches weighing between 10 and 25 kilograms with 1000 to 3000 fruitlets per bunch. Each fruitlet is almost spherical or elongated in shape. Generally, the fruitlet is dark purple, almost black and the colour turns to orange red when ripe. Each fruitlet consists of a hard kernel (seed) enclosed in a shell (endocarp) which is surrounded by a fleshy mesocarp. The oil palm is a unique crop as it produces two types of oil from its fruit; palm oil from the mesocarp and palm kernel oil from the kernel.
Commonly three fruit forms or “varieties” of oil palm can be identified based on the thickness of the shell criterion.
- The Dura has a shell thickness between 2 to 8 mm, the fleshy mesocarp of Dura yields between 15 to 17% oil
- While the Pisifera has no shell, the oil yield is more than 23%.
- The shell thickness of the hybrid Tenera is between 0.2 to 2 mm, while in Tenera yields between 21 to 23% oil
- According to commercial purpose, Pisifera is not cultivated on large scale because of its ability to fruits abortion and thereby virtual empty bunches production.
- Tenera which is a hybrid of Dura and Pisifera varieties remains the commercial variety with 60 to 96% of mesocarp. The hybrid produces more fruit bunches than Dura.
Cultivated oil palms carry fruit from their fourth year onward. Palm fruit can then be harvested for 40-50 years with the maximum yield being reached after 12th year. In plantations they are normally replaced after 25 years. The oil palm gives the highest yield of oil per unit area compared to any other crop. Modern high-yielding varieties developed by breeding programs, under ideal climatic conditions and good management, are capable of producing in excess of 20 tonnes of bunches/ha/yr, with palm oil in bunch content of 25 percent. This is equivalent to a yield of 5 tonnes oil/ha/yr (excluding the palm kernel oil), which far outstrips any other source of edible oil.
Ideal climate for oil palm for maximising of oil yield.
• annual rainfall of 2000 mm or greater, evenly distributed, without a marked dry season, and preferably at least 100 mm in each month
• a mean maximum temperature of about 29–33°C and a mean minimum temperature of about 22–24°C
•sunshine of 5–7 h/day in all months and solar radiation of 15MJ/m2 per day
•It is adapted to a range of soil types. Tolerates low pH, but does not thrive at very high pH (greater than 7.5). Soil must be free draining.
1. Palm Oil : Production, Processing, Characterization, Uses , AOCS Press (2012)
2. The Oil Palm, 4th Edition, Blackwell Science (2003)
3. Fats and Oils Handbook, AOCS Press (1998)
4. Fact Sheets : Malaysia Palm Oil, MPOC & MPOB (2007)