Cocos nucifera, coconut

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Taxonomy

cellular organisms - Eukaryota - Viridiplantae - Streptophyta - Streptophytina - Embryophyta - Tracheophyta - Euphyllophyta - Spermatophyta - Magnoliophyta - Liliopsida - commelinids - Arecales - Arecaceae - Arecoideae - Cocoseae - Attaleinae - Cocos - Cocos nucifera

Palm trees (Arecaceae) at GeoChemBio

Taxonomy General description Distribution Ecology and habits Pictures of palms in Florida References

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Brief facts

• Taxonomic place

  Tribe Cocoseae contains many important species of palms including African oil palm (Elaeis spp.), peach palm (Bactris gasipaes), taparo (Attalea cuatrecasana ), motacu palms (Attalea speciosa) and others. Historically, at least 60 species were placed in genus Cocos, which are now belong to either Syagrus or Butia. Today, genus Cocos is monospecific. The fossils, Cocos zeylandica, C. sahnii, Palmoxylon sundaram and P. parthasarathyi, which have been found as far apart as New Zealand and India and wide distribution of modern C. nucifera in New World implicate such wide area that determination of place of coconut origin is very difficult. However, today, most scientists accept that the coconut probably has a Southeast Asia-Melanesian origin. The means of its dispersal and subsequent pan-tropical distribution in pre-industrial era is still in dispute.

• General description

  • C. nucifera is tall slender and graceful palm. The palm terminates in a crown of long pinnate leaves. Young leaves are bright green. Upon aging they turn golden, and upon dying, a bamboo tan. The coconut palm is a monocotyledon, and as such forms only one vegetative bud at the apex of the stem that produces all leaves. The bud, commonly called cabbage, consists of several folded embryonic leaves in the protected by sheaths of older leaves known as the leaf-sheath. If the bud is removed or extensively injured, the tree dies.
  • As other monocotyledons, the coconut doesn't have tap root. Instead, it produces uniform roots of three-eighths to half an inch in diameter. The number of roots in mature plant ranges from 1,500 to 7,000. The main roots can branch and produce many short-lived feeding roots which also branch forming a large absorptive surface that can extend for a distance of 25 feet around the stem. The roots are woody but elastic, rigid and strong. The hypodermis of the completely developed root is composed of cells with thick and hard water-proof walls. Water can enter section of the root behind the root which is only two or three inches long. This allows palm to tolerate salt sea water.
  • Unlike in dicotyledonous trees, strands of specialized cells that provide water and nutrients passage are distributed throughout the entire stem of the palm. There is no cambium layer and damaged tissue cannot be repaired. Wherever there are prevailing winds, as along the seashore where the wind generally blows inland, the palm leans toward the wind; along the edge of plantings it inclines toward the light.
  • The mature leaf, frequently 20 feet long, is composed of a strong leaf stalk, or petiole, and a mid-rib, or rachis, to which leaflets are attached. The leaf stalk must support the leaf, which frequently weighs 25 pounds, and the bunch of coconuts which grows in the leaf axil and weighs from 30 to 50 pounds. The stipules (outgrowths on either side of the base of leafstalk) reach almost half way around the stem at its point of attachment. Each new leaf is at an angle of about 144 degrees around the stem from the last one. On some palms the leaves spiral about the stem to the left and on others to the right. The leaflets near the base of the leaf are about 30 inches long and half an inch wide; those in the center, 40 to 50 inches long and one and a half to two and a half inches wide; those near the apex 18 inches long and one-quarter to one-half inch wide.

• Coconut palm uses by natives

  The coconut palm, economically speaking, is the most important member of the palm family. The various parts of the coconut palm are used in many ways by the natives of the tropics. Both the coconut meat and the milky juice constitute a large proportion of the diet. For local usage, the meat of the mature nut is boiled in water, the oil drawn off and can be used for cooking and as fuel in lamps. The sap of the unexpanded flower spathe provide a drink, can be converted into syrup or sugar; or, if fermented, may be distilled to make alcoholic beverage, arrack. Coconut shells are used for fuel, as kitchen utensils, buttons, mulch and other uses. Charcoal prepared from shells is exported for use as an absorbent in gas masks. The fiber of the outer husk of the nut is known as coir. From it durable and salt resistant ropes, upholstery material and brushes are made. The leaves of the palm serve as roof thatching, flooring, wall fabricating and as matting. Leaves are also plaited into fans, baskets and numerous other things. The trunk is used as timber for building houses and furniture, as well as firewood. The wood of the coconut palm is known in the lumber trade as "porcupine wood". The root of the coconut palm is used by the natives for brewing beverages and for medicinal purposes.

• Coconut palm products for export

  The coconut palm was first grown as a plantation crop in the 1840'. Soon it became a cheap source of oil for a soap industry. The development of dynamite from nitroglycerine between 1846 and 1867 had the remarkable effect of turning a once discarded by-product of soap manufacture, glycerin, into the most profitable side of the business. Coconut oil also replaced animal fat in the manufacture of margarine (patented in 1896). Up to date, copra (dried and cured coconut meat) and coconut oil are most important coconut products in world trade. Copra is used for oil extraction and for the preparation of shredded desiccated coconut which together with the oil is popular in the bakery and confectionery trades. Coconut oil is also used extensively in cosmetics, emulsions, vegetable shortening and lard-compound, margarine, ointments, salves, perfumery, flavoring and soap. It is an essential ingredient in the manufacture of synthetic rubber. It is used as a plasticizer in many products. It serves as a substitute for cacao butter in the manufacture of chocolate. It is also being used as a fuel for diesel engines.

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Growth stages (life cycle)

Life Cycle Stages

• Mature fruit Many coconuts that fall on the beaches are carried to sea by the ebb and flow of the tide. The hard-surfaced outer husk safeguards the inner nut for months while it is seaborne. Dormancy is no advantage for plant that habitat is constantly warm and humid tropical climate. The distance a fruit can float and remain viable will therefore be limited by the time it takes to germinate. A thick husk contributes to slow germination as well as to floating ability. Coconuts can cover thousands of miles when carried by ocean currents for months.
• Germination Seed coconuts preferably are selected from palms of good growing habits and of high yield. The highest yield of coconuts comes from palms having the most leaves and the most compact crowns. A compact crown True germination, the development of the embryo through the "soft eye" of the nut beneath the husk cannot be observed. The point of the sprout emerging through the husk is counted as germination. For coconut, germination may range from 30 to 220 days.
• Seedling Upon germination of the nut, seedling grows from the embryo by sending a leaf-bearing stem through the husk. Roots grow from the base of the germinating plant downward around the nut's shell, through the mesoderm and finally emerging through it to grow down into the soil. The roots obtain food from the mesoderm and later from the soil. The plant also grows a "nursing-foot" inside the cavity. The foot eventually fills the cavity and by converting meat and milk into sugars provides nutrients to the plant depleting endosperm in 12 to 15 months. During this period the roots become established in the soil. In naturally disseminated coconut, the shoot grows where the fruit falls, rolls or floats. This means that practically all inland sites are inaccessible. Coconut seedling cannot survive long if it floats in sea water, despite the palm's salt tolerance. For cultivation, four to eight months old seedlings are set in the field. Transplanting is practiced during the wet season.
• Non-bearing palm Young plant up to 5 year old.
• Young plant From 5 to 20 years old. Under average conditions the tree starts bearing at seven years of age and reaches its full bearing potential at about 10 years.
• Mature palm Over 20 years old. Mature palm is usually 60 to 100 feet tall, and its cylindrical stem may attain a diameter of two feet.
  • Flowering Inflorescence is produced in the axil of each leaf on a mature tree and bears both male and female flowers. It is enclosed in a spathe (a large bract that forms a sheath to enclose the flower cluster). Main stem of the inflorescence grows up to five to six feet. The stem bears some 40 secondary branches, or spikelets, which bear flowers. Generally one female flower is located near the base of each spikelet, and large numbers of male flowers are borne between the female flower and the tip of the spikelet. When an inflorescence bursts from the spathe, flowering begins with male flowers from top of each spikelets and progresses towards its base. About 15 days are required for all the male flowers to open and die and then, the female flowers open. There are no two branches flowering at the same time on one palm. Thus, male and female flowers never open simultaneously on one tree. This necessitates cross-pollination. Cross-pollination is assisted by insects, attracted by the honey produced by the three honey glands of each female flower. Because of this cross-pollination there is considerable variation in the progeny within one tree and even within one bunch of nuts.
  • Fruiting About 14 leaves on a tree will have fruit clusters in their axils, six or eight will remain on the palm after the fruit has been harvested, and the remaining 10 or 12 will be young growing leaves too young to have flowers in their axils. Coconuts may be harvested throughout the year, since the nuts reach maturity at different times. The greatest number of fruits per tree occurs in the East Indies in May, June and July when the maximum number of female flowers is pollinated; the fewest in November, December and January. Fruit is set every 26 days, the interval at which new leaves are laid down on the average palm.
  • Ripening The nut requires a year to ripen. The meat starts to form at about the 6^th month, and oil accumulates in the cells as the nut approaches maturity. The cavity of the kernel is filled with milk during immaturity but only partly filled with it at maturity. The meat (endosperm) is completely formed by the 10^th month, but the shell does not fully harden until the 12^th month.
  • Harvesting In harvesting, some coconuts are picked up from the ground after they have fallen from the palm. The better plan is to pick them from the plant a month or two before they fall, at which time the meat of the nut is well matured. Harvesting is done every two or three months, and two or three bunches of nuts are cut per palm. A palm can bear fruit continuously for a period of up to 70 years.

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Growth conditions and ecology

Temperature

The coconut palm is a true tropical tree and cannot withstand cool or cold weather. A mean annual temperature of about 68 °F is necessary, and the optimum annual temperature is 80 °F or higher. Most of the lands which meet these temperature requirements are located between the Tropics of Cancer and Capricorn, exclusive of the highland regions.

Precipitation

The coconut palm requires heavy rainfall. The tree can survive and produce a little fruit with an annual precipitation of as little as 40 inches, but for optimal growth a yearly rainfall of at least 60 inches and more is needed. Because the tree stores little moisture and it lacks a tap root the rainfall must be distributed evenly throughout the year. However, the coconut palm may thrive in areas with a prolonged dry season provided that the ground-water level remains high.

Soil

For best results the following conditions are necessary: (1) a loose, porous soil, preferably sand or alluvium (heavy clay soils are detrimental to growth and yields); (2) a continuously high water-table; (3) rapid and continuous movement of ground-water (stagnant ground-water is very injurious to the palm).
The most common place where these conditions are simultaneously met is along seashores backed by highlands. Porous sandy beaches experience rapid and constant movement of ground-water caused by the ebb and flow of the tide, and are the last to react to a period of drought by a lowering of the water-table.

Coconut palms grow along the tropical coasts throughout Latin America. This scene is typical of the Caribbean.

Hurricanes

Severe windstorms are common in many coconut-growing regions. For the naturally evolving Cocos high winds and rain assist dissemination of the fruit and, by destroying many or all of the bearing palms, allow the next generation to establish and outnumber the survivors. As a result, phenotypes that help palms to withstand hurricanes are not necessarily selected in nature.

Where coconuts are cultivated, windstorm is a disaster, destroying a source of food, drink, shelter and fuel on which man came to rely. Any palms that survive will be chosen to produce the next generation. This leads to selection for a larger root system recognized at ground level by a larger bole and increased trunk girth, i.e. cultivated coconuts gradually diverge from wild ones.

Plantation and pasture integration

The integration of livestock with tree crops in general and with Cocos nucifera in particular for increasing field productivity is practiced widely in the humid tropics. It has been suggested that if only half the tree crop area could be integrated, then the livestock population of the humid tropics could be increased by some 25% without utilizing any new land.

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Anatomy of coconut fruit

The coconut is a fibrous drupe. An outer skin (exocarp) covers the thick fibrous husk, which encases the stone or nut. Exocarp in immature fruit is green. The nut is formed by the fusion of three carpels which are represented by three ridges on its surface. Only one of the fused carpels develops into the mature coconut but each of them is represented by an "eye" at the proximal, or stem, end of the nut. Two of these eyes are hard and smaller than the third. The embryo is located under the larger and soft eye, which connects with the milk-containing cavity of the nut.

The nut consists of a shell (endocarp), a seed coat or testa (located between the shell and the meat), oil-bearing meat and liquid milk. The fruit endocarp usually is presumed to protect the developing seed from predation, desiccation, or crushing.

Coconut seedlings.

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Processing of coconuts in small family buisness operation in Dominican Republic.

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References

• Reynolds SJ. Some Factors of Importance in the Integration of Pastures and Cattle with Coconuts (Cocos nucifera) Journal of Biogeography, Vol. 15, No. 1, Biogeography and Development in the Humid Tropics (Jan., 1988), pp. 31-39
• Deasy JF. Location Factors in the Commercial Coconut Industry Economic Geography, Vol. 17, No. 2 (Apr., 1941), pp. 130-140
• Bertrand M. The Training without Reward: Traditional Training of Pig-Tailed Macaques as Coconut Harvesters. Science, New Series, Vol. 155, No. 3761 (Jan. 27, 1967), pp. 484-486
• Quisumbing E and Juliano JB. Development of Ovule and Embryo Sac of Cocos Nucifera. Botanical Gazette, Vol. 84, No. 3 (Nov., 1927), pp. 279-293
• Ward RG and Brookfield M. The Dispersal of the Coconut: Did It Float or Was It Carried to Panama? Journal of Biogeography, Vol. 19, No. 5 (Sep., 1992), pp. 467-480
• Gunn BF. The Phylogeny of the Cocoeae (Arecaceae) with Emphasis on Cocos nucifera. Annals of the Missouri Botanical Garden, Vol. 91, No. 3 (Oct., 2004), pp. 505-522
• Moore OK. The Coconut Palm: Mankind's Greatest Provider in the Tropics. Economic Botany, Vol. 2, No. 2 (Apr. - Jun., 1948), pp. 119-144
• Dennis JV and Gunn CR. Case against Trans-Pacific Dispersal of the Coconut by Ocean Currents. Economic Botany, Vol. 25, No. 4 (Oct. - Dec., 1971), pp. 407-413
• Harries HC. The Evolution, Dissemination and Classification of Cocos nucifera L. Botanical Review, Vol. 44, No. 3 (Jul. - Sep., 1978), pp. 265-319

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