Elaeis guineensis is a species of palm commonly called African oil palm or macaw-fat. It is the principal source of palm oil. It is native to west and southwest Africa, specifically the area between Angola and the Gambia; the species name guineensis refers to the name for the area, Guinea, and not the modern country which now bears that name. The species is also now naturalised in Madagascar, Sri Lanka,Malaysia, Sumatra, Central America, the West Indies and several islands in the Indian and Pacific Oceans. The closely related American oil palm Elaeis oleifera and a more distantly related palm, Attalea maripa, are also used to produce palm oil.
Human use of oil palms may date as far back as 5,000 years in West Africa; in the late 1800s, archaeologists discovered palm oil in a tomb at Abydos dating back to 3,000 BCE. It is thought that Arab traders brought the oil palm to Egypt.
Nutrient uptake is low during the first year but increases steeply between year one and year three (when harvesting commences) and stabilizes around years five to six. Early applications of fertilizer, better planting material, and more rigid culling have led to a dramatic increase in early yields in the third to sixth years from time of planting. In regions without a significant drop in rainfall, yields of over 25 tonnes of fresh fruit bunches per hectare have been achieved in the second year of harvesting.
Nitrogen deficiency is usually associated with conditions of water-logging, heavy weed infestation, and topsoil erosion. Symptoms are a general paling and stiffening of the pinnae, which lose their glossy lustre. Extended deficiency will reduce the number of effective fruit bunches produced, as well as the bunch size.
Phosphorus-deficient leaves do not show specific symptoms, but frond length, bunch size, and trunk diameter are all reduced.
Potassium deficiency is very common and is the major yield constraint in sandy or peaty soils. The most frequent symptom is "confluent orange spotting". Pale green spots appear on the pinnae of older leaves; as the deficiency intensifies, the spots turn orange or reddish-orange and desiccation sets in, starting from the tips and outer margins of the pinnae. Other symptoms are "orange blotch" and "midcrown yellowing". In soils having a low water-holding capacity (sands and peats), potassium deficiency can lead to a rapid, premature desiccation of fronds.
Copper deficiency is common on deep peat soils and occurs also on very sandy soils. It appears initially as whitish-yellow mottling of younger fronds. As the deficiency intensifies, yellow, mottled, interveinal stripes appear, and rusty, brown spots develop on the distal ends of leaflets. Affected fronds and leaflets are stunted and leaflets dry up. On sandy soils, palms recover rapidly after a basal application of 50 grams of copper sulphate. On peat soils, lasting correction of copper deficiency is difficult, as applied copper sulphate is rendered unavailable. A promising method of correcting copper deficiency on peat soil is to mix copper sulphate with clay soil and to form tennis-ball sized "copper mudballs" that are placed around the palm to provide a slow-release source of available copper.
Healthy, well selected seedlings are necessary for early and sustained high yield. In most cases, granular multinutrient compound fertilizers are the preferred nutrient source for seedlings in the nursery. Where subsoil is used to fill the polybags, extra dressings of Kieserite may be required (10-15 g every six to eight weeks). Where compound fertilizers are not available, equivalent quantities of straight materials should be used.
To maintain good fertilizer response and high yields in older palms, selective thinning is often necessary.