Cocos nucifera L.
Family
Palmae
Synonyms
Cocos nana Griff.
Vernacular Names
|
Malaysia |
Kelapa. |
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English |
Coconut (Palm and fruit). |
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Indonesia |
Kelapa (General), nyiur (Malay), krambil (Javanese). |
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Papua New Guinea |
Kokonas. |
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Philippines |
Niyog (Pilipino, Tagalog), in-iug (Ibanag), lubi, ungut (Bisaya), laying (Manobo). |
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Myanmar |
Ong. |
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Cambodia |
Doong. |
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Laos |
Phaawz. |
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Thailand |
Ma phrao (General), khosaa (Karen-Mae Hong Son), dung (Chong-Chan-thaburi). |
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Vietnam |
D[uwf]a. |
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French |
Cocotier (palm), coco (fruit). |
Geographical Distributions
Cocos nucifera is native to the coastal regions of tropical Asia and the Pacific, but its primary centre of origin is the subject of speculation. Fossil of Cocos nucifera has been found as far apart as India and New Zealand. The ability of the thickly husked and slow-germinating fruit of wild coconut (called Niu Kafa type) to remain viable after floating long distances at sea ensured wide natural dispersal in the Indo-Pacific long before domestication may have started in Malaysia. The domesticated coconut (called Niu Vai type) has a robust stem and large fruits, which however cannot survive long periods of floating at sea because of thinner husks and shells and quicker germination. Initial dissemination of the domesticated Cocos nucifera coincided with migrations of Malay people to the Pacific and India, which started some 3000 years ago. Where wild coconut already occurred, there was opportunity for introgression with domesticated types, as both retained full cross compatibility. Polynesian, Malay and Arab navigators played an important role in further dispersal of Cocos nucifera into the Pacific, Asia and East Africa. Cocos nucifera became truly pantropical in the 16th Century after European explorers had taken it to West Africa, the Caribbean and the Atlantic coast of tropical America.
Description
Cocos nucifera is an unarmed, unbranched, pleonanthic, monoecious palm tree and with a terminal crown of leaves. It can grow up to 20-30 m in tall cultivars and 10-15 m in dwarf cultivars. The roots are mostly 1.5 m in the top layer of soil, normally measuring 6 m x 1 cm and up to 30 m long in optimum soil conditions. Its stem is cylindrical, erect, often curved or slanting, measures 20-40 cm in diametre, but the swollen base (‘bole’) is up to 60 cm. It is light grey, becomes bare and conspicuously ringed with scars of fallen leaves.
The leaves are sheathing, spirally arranged, pinnate, measure 4.5-6(-7) m long, and up to 60-70 per plant of which one half is still unfolded in the central spear. The petiole is stout with clasping, fibrous sheath at the base, about one quarter of total leaf length, grooved above and rounded beneath. There are 200-250 leaflets which are linear-lance-shaped, and measuring 50-120 cm x 1.5-5 cm. They are single folded lengthwise at base, with acute apex and regularly arranged in one plane.
The inflorescence is an axillary, protandrous, unopened (immature) raceme which looks like a spadix within a spathe. It is opened (mature) about 1-2 m long, consists of a central axis with up to 40 lateral, spirally arranged, spike-like rachillae (branches), of which each bears 200-300 male flowers and with only one to few female flowers near the bare basal part. The male flowers are 1-3 together, sessile, measuring 0.7-1.3 cm x 0.5-0.7 cm, pale yellow, with 3 small sepals, 3 larger petals, 6 stamens in 2 whorls and a rudimentary pistil. The female flowers are solitary, much larger than male flowers, spherical in bud, ovoid at anthesis, measure 2-3 cm in diametre, enveloped by 2 small scaly bracteoles, 3 sepals and 3 petals, suborbicular, sub-equal, persistent and enlarged in fruit. The pistil is with large 3-locular ovary, 3 sessile triangular stigmas and 3 nectaries near the ovary base.
The fruit is a spherical, ovoid or ellipsoidal fibrous drupe. It is indistinctly 3-angled, measures 20-30 cm long and weighs up to 2.5 kg. The exocarp is very thin, measures 0.1 mm thick, smooth, green, brilliant orange, yellow to ivory-coloured when ripens and usually drying to grey-brown in old fruits. The mesocarp is fibrous, measures 4-8 cm thick and pale brown. The endocarp (shell, together with its contents are called the ‘nut’ of commerce) is ovoid, measures 10-15 cm in diametre, 3-6 mm thick, hard, stony, dark brown, indistinctly 3-angled with 3 longitudinal ridges and 3 large, slightly sunken pores (‘eyes’) at basal end and each with an operculum.
There is only 1 large seed with a thin brown testa that is closely appressed to endocarp and adhering firmly to endosperm (‘meat’), which is firm, measures 1-2 cm thick, white and oily. At the basal end in endosperm, a small peglike embryo 0.5-1 cm long is embedded (under one of the endocarp pores). In the centre of seed, there is a large central cavity, partially filled with coconut water, which is completely absorbed 6 months after harvesting.
Ecology / Cultivation
Cocos nucifera is essentially a crop of the humid tropics. It is fairly adaptable to temperature and water supply. Hence, it is highly valued as still being common near the limits of its ecological zone. The annual sunlight requirement is above 2000 hours, with a likely lower limit of 120 hours per month. The optimum mean annual temperature is estimated at 27°C with average diurnal variation of 5-7°C. For good yield, a minimum monthly mean temperature of 20°C is required. Temperatures below 7°C may seriously damage young palms, but cultivars differ in their tolerance of low temperature. While most Cocos nucifera is planted in areas below 500 m, it may thrive at altitudes up to 1000 m, although low temperatures will affect growth and yield. Generally, palms grow in areas with evenly distributed annual rainfall of 1000-2000 mm and high relative humidity, but they can still survive in drier regions if there is adequate soil moisture. The semi-xerophytic leaves enable Cocos nucifera to minimize water loss and withstand drought for several months. In India, a monthly rainfall of 150 mm (with only a 3-month dry period) is enough, while in the Philippines, rainfall of 125-195 mm (1500-2300 mm annually) is ideal. Cocos nucifera thrives in a wide range of soils, from coarse sand to clay, if soils have adequate drainage and aeration. Cocos nucifera is halophytic and tolerates salt in the soil well. Cocos nucifera can grow in soils with a wide range of pH but grows best at pH 5.5-7.
Line Drawing / Photograph
References
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Plant Resources of South-East Asia No.14: Vegetable oils and fats.
