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22 April 2014

Cocos nucifera (coconut)

Datasheet Types: Crop, Tree, Invasive species, Host plant

Abstract

This datasheet on Cocos nucifera covers Identity, Overview, Associated Diseases, Pests or Pathogens, Distribution, Dispersal, Biology & Ecology, Environmental Requirements, Impacts, Uses, Management, Genetics and Breeding, Food Quality, Food Safety, Economics, Further Information.

Identity

Preferred Scientific Name
Cocos nucifera L.
Preferred Common Name
coconut
Other Scientific Names
Calappa nucifera (L.) Kuntze
Cocos indica Royle
Cocos nana Griffith
Cocos nucifera var. synphyllica Becc.
International Common Names
English
coconut palm
copra
Spanish
coco de agua
cocotero
palma de coco
palmera cocotera
palmera de coco
French
coco
cocotier
cocoyer
noix de coco
Chinese
ye zi
Portuguese
coqueiro
Local Common Names
American Samoa
niu
Brazil
coco da India
coco de Bahia
coco-da-bahia
coco-da-índia
coqueiro
coqueiro-da-bahia
coqueiro-da-índia
inaiá-guaçuíba
inajá-guaçú
Cambodia
dôong
Caribbean
cocos
cocospalm
klapperboom
Cuba
coco blanco
coco indio
coco morado
Germany
Kokosnusspalme
India
narikel
nariyal
narlu
thengu
yubi
Indonesia
kelapa
Italy
cocco
Laos
phaawz
Lesser Antilles
cocotier
noix de cocos
Malaysia
kelapa
Netherlands
Kokospalm
Northern Mariana Islands
nizok
Philippines
iniúg
lubi
niog
niyóg
Sweden
Kokospalm
Thailand
ma phrao
Vietnam
dùa
EPPO code
CCNNU (Cocos nucifera)

Pictures

Cocos nucifera (coconut palm); habit. Kahanu Gardens NTBG, Kaeleku Hana, Maui, November, 2009.
Habit
Cocos nucifera (coconut palm); habit. Kahanu Gardens NTBG, Kaeleku Hana, Maui, November, 2009.
©Forest & Kim Starr-2009 - CC BY 3.0
Cocos nucifera (coconut palm); habit. Kapuaiwi Coconut Grove, Kaunakakai, Molokai, Hawaii, USA. April , 2012.
Habit
Cocos nucifera (coconut palm); habit. Kapuaiwi Coconut Grove, Kaunakakai, Molokai, Hawaii, USA. April, 2012.
©Forest & Kim Starr-2012 - CC BY 3.0
Cocos nucifera (coconut palm); habit. Lake Trail, Laysan. September 12, 2013
Habit
Cocos nucifera (coconut palm); habit. Lake Trail, Laysan. September 12, 2013
©Forest & Kim Starr-2013 - CC BY 3.0
Cocos nucifera (coconut palm); crown and fruit. YMCA Keanae, Maui, Hawaii, USA. May, 2009.
Crown and fruit
Cocos nucifera (coconut palm); crown and fruit. YMCA Keanae, Maui, Hawaii, USA. May, 2009.
©Forest & Kim Starr-2009 - CC BY 3.0
Cocos nucifera (coconut palm); crown and fruit. Makawao, Maui, Hawaii, USA. December, 2006.
Crown and fruit
Cocos nucifera (coconut palm); crown and fruit. Makawao, Maui, Hawaii, USA. December, 2006.
©Forest & Kim Starr-2006 - CC BY 3.0
Cocos nucifera (coconut palm); fruits. Kanaha pond, Maui, Hawaii, USA. February, 2001.
Fruits
Cocos nucifera (coconut palm); fruits. Kanaha pond, Maui, Hawaii, USA. February, 2001.
©Forest & Kim Starr-2001 - CC BY 3.0
Cocos nucifera (coconut palm); fruits. Kanaha Beach, Maui, Hawaii, USA. November, 2006.
Fruits
Cocos nucifera (coconut palm); fruits. Kanaha Beach, Maui, Hawaii, USA. November, 2006.
©Forest & Kim Starr-2007 - CC BY 3.0
Cocos nucifera (coconut palm); fruit. Community Garden, Sand Island, Midway Atoll. June, 2008.
Fruit
Cocos nucifera (coconut palm); fruit. Community Garden, Sand Island, Midway Atoll. June, 2008.
©Forest & Kim Starr-2008 - CC BY 3.0
Cocos nucifera (coconut palm); fruit. Kahului, Maui, Hawaii, USA. April, 2001.
Fruit
Cocos nucifera (coconut palm); fruit. Kahului, Maui, Hawaii, USA. April, 2001.
©Forest & Kim Starr-2007 - CC BY 3.0
Cocos nucifera (coconut palm); habit, young tree nr ocean. Honomanu, Maui, Hawaii, USA. June, 2009.
Habit
Cocos nucifera (coconut palm); habit, young tree nr ocean. Honomanu, Maui, Hawaii, USA. June, 2009.
©Forest & Kim Starr-2007 - CC BY 3.0
Cocos nucifera (coconut palm); young plants with Laysan albatross chick. Commodore Avenue, Sand Island, Midway Atoll. June, 2008.
Young plants with Laysan albatross chick
Cocos nucifera (coconut palm); young plants with Laysan albatross chick. Commodore Avenue, Sand Island, Midway Atoll. June, 2008.
©Forest & Kim Starr-2008 - CC BY 3.0
Cocos nucifera (coconut palm); seedling pile and Laysan albatross chicks. Cannon School field, Sand Island, Midway Atoll. June, 2008.
Seedling pile and Laysan albatross chicks
Cocos nucifera (coconut palm); seedling pile and Laysan albatross chicks. Cannon School field, Sand Island, Midway Atoll. June, 2008.
©Forest & Kim Starr-2008 - CC BY 3.0
Cocos nucifera (coconut palm); coconut fruit and shell litter on boulder beach. Lelekea, Maui, Hawaii, USA. May, 2004.
Coconut fruit and shell litter
Cocos nucifera (coconut palm); coconut fruit and shell litter on boulder beach. Lelekea, Maui, Hawaii, USA. May, 2004.
©Forest & Kim Starr-2004 - CC BY 3.0
Image (coconut3.JPG) is missing or otherwise invalid.
Nursery seedlings
Cocos nucifera (coconut palm); nursery seedlings.
©AgrEvo

Overview

The genus Cocos is monotypic, containing only the highly variable species Cocos nucifera. Coconut palm trees grow 20-30 m tall and live 80-100 years, and are distributed throughout the tropics. Humans have used coconut palm for thousands of years for food, thatch, fibre and wood, and it entered commercial trade in the mid-1800s as a source of oil for lamps, candles and soap. The coconut fruit (‘nut’) is used fresh at both the immature and mature stages. The kernel (solid endosperm) from mature coconuts can be shredded and dehydrated to become desiccated coconut. Coconut oil can be extracted and processed as an edible oil from the fresh kernel or as an industrial oil from the kernel that has been dried (in the sun, over a fire, in a kiln) or fried (in hot oil) to give copra. The outer husk (mesocarp) of the fruit is used as a fibre (coir) and as a non-fibrous product, coir dust (‘cocopeat’), which now has widespread uses in horticulture as a replacement for peat. There has always been local trade in immature fruit and dehusked mature nuts for eating, and modern technology is making coconut water available internationally.
Principal sources: Janick and Paull (2008)

Importance

C. nucifera is believed to have originated in the Indo-Malayan to Western Pacific region (Parrotta, 1993) and is now of pan-tropical distribution, mainly the result of cultivation for its nuts and by natural dispersal by the oceans. It can be cultivated up to an elevation of 1200 m near the equator or 900 m at higher latitudes (Moistero, 1978), with annual rainfall of 700-5000 mm but growth and fruit production are reduced at the extremes (Parrotta, 1993). Commercial production of coconuts is mainly concentrated in low coastal lands. It prefers deep, fertile and adequately drained soils at pH 5.5 - 6.5, with either a high water-table or continually replenished surface soil moisture (Francis and Liogier, 1991; PCARRD, 1993). Generally, C. nucifera is propagated from seeds (the nuts), which take 8-10 weeks to germinate and 30 weeks to reach planting-out size. It is intolerant of shade, self-pruning, highly resistant to wind damage and may tolerate some salinity (Parrotta, 1993). Besides its nuts, C. nucifera trees are of enormous general utility. The timber is used for poles, construction, furniture, boxes, fixtures, particle board, paper pulp, charcoal, and occasionally veneers. The wood is difficult to saw, requiring tungsten carbide teeth. Coconut milk may be drunk or used as a medium for tissue culture; the copra (dried endosperm) is used for extraction of oils for use in foods, cosmetics, and medicines; the cori (mesocarp fibres) is used to construct mats, ropes, carpets, brushes, brooms, and bags, packaging, and potting media; the shell is used to make bowels, cups, spoons, ladles, smoking pipes, ashtrays, vases, boxes, and toys. The leaves are used in thatching, and the terminal bud may be eaten as a vegetable. The roots have medicinal properties, and provide a sweet sucrose-rich liquid known as toddy (Westphal and Jansen, 1989).

Summary of Invasiveness

C. nucifera is a palm tree with a great capacity for natural dispersal. The nuts have the capability to survive up to 120 days floating in the sea water and germinate when they make landfall. This dispersal trait facilitates the spreading of this species far from its origin without human assistance (Chan and Elevitch, 2006). Once established in new coastal areas, C. nucifera can grow forming dense monospecific thickets (Young et al., 2010). Humans have also actively introduced large numbers of coconut palms inland from the natural coastal habitat of the species, and nuts (fruits) can move up to 10 m from the mother tree when growing inland. In addition to its great dispersal ability, C. nucifera has high germination rates, and nuts have no dormancy and do not require special treatments to germinate, which are also elements facilitating its establishment and spread into new habitats (Duke, 1983; Chan and Elevitch, 2006). 

Taxonomic Tree

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Notes on Taxonomy and Nomenclature

The family Arecaceae includes 183 genera and 2361 species distributed mostly in humid tropical and subtropical regions of the world (Stevens, 2012).  The species C. nucifera (coconut) has a number of commercial and traditional cultivars. Coconut palm contains tall cultivars, sometimes referred to as var. typica, as well as dwarf cultivars, sometimes referred to as var. nana (Griff.) Nar. Opinions about the origin of the dwarf differ. Aspects such as drought resistant, cold tolerant, seed size, shape and weight are important factors in the selection of new cultivars. 

Plant Type

Perennial
Seed propagated
Tree
Woody

Description

C. nucifera palms are unbranched, monoecious trees with smooth, columnar, light grey-brown trunk, usually 9-18 m height and sometimes taller (up to 30 m); dwarf selections also exist. Leaves pinnate, feather shaped, 4-7 m long and 1-1.5 m wide at the broadest part. Leaf stalks 1-2 cm in length and thorn-less. Inflorescence consists of female and male axillary flowers. Flowers are small and light yellow, in clusters that emerge from canoe-shaped sheaths among the leaves. Male flowers are small and more numerous. Female flowers 1 or fewer than male flowers; larger, spherical structures, about 25 mm in diameter. Fruit a drupe, roughly ovoid, up to 30 cm long and 20 cm wide, composed of a thick, fibrous husk surrounding a somewhat spherical nut with a hard, brittle, hairy shell. The fruit consists of (from the outside to in) a thin hard skin (exocarp), a thicker layer of fibrous mesocarp (husk), the hard endocarp (shell), the white endosperm (kernel), and a large cavity filled with watery liquid (coconut water or milk). The endosperm is soft and jellylike when immature but becomes firm with maturity. Coconut water or milk is abundant in unripe fruit but is gradually absorbed as ripening proceeds. The fruits are green at first, turning brownish as they mature; yellow varieties go from yellow to brown (Chan and Elevitch, 2006; Orwa et al., 2009).

Distribution

C. nucifera is native to coastal areas of Melanesia and South-East Asia, probably Malaysia, Indonesia (Moluccas Islands), Philippines and Papua New Guinea (Chan and Elevitch, 2006; USDA-ARS, 2014). The species is a common component of island and coastal ecosystems around the world, occurring in more than 80 countries across Asia, Africa, America and Oceania (Chan and Elevitch, 2006; Orwa et al., 2009; USDA-ARS, 2014). 

Distribution Map

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Distribution Table

This content is currently unavailable.

History of Introduction and Spread

In prehistoric times, wild forms of C. nucifera are believed to have been carried on oceanic currents to islands in the Pacific (Melanesia, Polynesia, and Micronesia) and to coastal India, Sri Lanka, and islands in the India Ocean (i.e., Seychelles, Andaman, and Mauritius). It is also believed that Polynesians migrating into the Pacific 4500 years ago brought with them coconut palms. At about the same time, people from Indo-Malaysia were colonizing islands in Micronesia. About 3000 years ago, Malay and Arab traders spread improved coconut types to India, Sri Lanka and East Africa (Chan and Elevitch, 2006). During the sixteenth century, European explorers introduced C. nucifera into West Africa, the Atlantic Coast of America and the West Indies (Little and Skolmen, 2003; Chan and Elevitch, 2006). The arrival of Europeans in the Pacific islands in the nineteenth century signalled the international commercialization of this species and coconut oil was the first vegetable oil commercialized in world trade. During this period, large coconut plantations were established in European colonies around the world including India, the Philippines, Tanzania, Papua New Guinea, the Solomon Islands, Fiji, Vanuatu and Samoa (Duke, 1983; Chan and Elevitch, 2006; PROTA, 2014). 

Means of Movement and Dispersal

C. nucifera spreads only by seeds. Seeds are dispersed by water, gravity and by people. Naturally, nuts reach new coastal areas floating in the sea water. Plants growing inland can disperse their nuts up to 10 metres just by gravity, however, the spreading of coconut plants inland is performed primarily by humans (Chan and Elevitch, 2006; Orwa et al., 2009).

Pathway Causes

Pathway causeNotesLong distanceLocalReferences
Crop production (pathway cause)Planted in plantations as overhead shade treeYesYes
Disturbance (pathway cause)Planted in disturbed areasYesYes
Food (pathway cause)CoconutYesYes
Habitat restoration and improvement (pathway cause)Planted to stabilise coastal areasYesYes
Hedges and windbreaks (pathway cause)One of the most wind tolerant plants in the worldYesYes
Horticulture (pathway cause)Nut kernels are used to feed animalsYesYes
Industrial purposes (pathway cause)Coconut oilYesYes
Landscape improvement (pathway cause)Hotels in coastal areasYesYes
Ornamental purposes (pathway cause)Mostly coastal areasYesYes
People foraging (pathway cause)Coconut kernel, coconut cream, coconut water, heart of the palmYesYes
Timber trade (pathway cause)Stems are used for poles, sawn timber, roofing shingles, handcraft and furnitureYesYes

Pathway Vectors

Pathway vectorNotesLong distanceLocalReferences
Floating vegetation and debris (pathway vector)Nuts can survive up to 120 days floating in the seaYesYes
Water (pathway vector)Nuts can survive up to 120 days floating in the seaYesYes

Habitat

C. nucifera grows on sandy beaches and coastal areas in tropical and subtropical regions of the world. This species has been introduced inland by humans and can be found planted and naturalized in gardens, parks, plantations, and along roadsides in areas with abundant sunlight, regular rainfall (1500 mm to 2500 mm annually) and high temperatures throughout the year (21°C to 30°C annually; Chan and Elevitch, 2006; Orwa et al., 2009).

Habitat List

CategorySub categoryHabitatPresenceStatus
Terrestrial    
TerrestrialTerrestrial – ManagedCultivated / agricultural landPresent, no further detailsProductive/non-natural
TerrestrialTerrestrial – ManagedManaged forests, plantations and orchardsPresent, no further detailsProductive/non-natural
TerrestrialTerrestrial – ManagedDisturbed areasPresent, no further detailsProductive/non-natural
TerrestrialTerrestrial – ManagedRail / roadsidesPresent, no further detailsProductive/non-natural
TerrestrialTerrestrial – ManagedUrban / peri-urban areasPresent, no further detailsProductive/non-natural
Littoral Coastal areasPresent, no further detailsHarmful (pest or invasive)
Littoral Coastal areasPresent, no further detailsNatural
Littoral Coastal areasPresent, no further detailsProductive/non-natural
Littoral Coastal dunesPresent, no further detailsHarmful (pest or invasive)
Littoral Coastal dunesPresent, no further detailsNatural
Littoral Coastal dunesPresent, no further detailsProductive/non-natural

Biology and Ecology

Growth and Development

Tall palms produce about 10 leaves during the first year, dwarf palms about 14. In subsequent years, more and ever-larger leaves are formed, until full leaf size is attained and annual production levels off at 12-16 leaves for tall and 20-22 leaves for dwarf palms. Since a leaf of a tall palm remains on the tree about 2.5 years after unfolding, the leaf number in the crown levels off at 30-35 after 6 or 7 years. The emerging 'spear' leaf replaces the eldest leaf which is about to fall; in this way the canopy reaches a steady state in respect of leaf area and leaf age. The spear leaf represents the midway-stage between initiation and fall, because the number of leaf initials still enfolded by the spear leaf is about equal to the number of unfolded leaves.
The numbers of adventitious roots are high: normally 2000-4000 per palm. Like the leaves, the roots are replaced in a regular fashion: new roots emerging from the trunk above the others take over from decaying roots. There are no data available on the rate of root replacement.
The steady state of both the canopy and the root system suggests that the coconut palm is built for a steady pace of growth in a constant environment. The large organs spend a long period in the pipeline – for example, about 2.5 years from initiation to unfolding for a leaf – and these long lead times give the palm a certain inflexibility. Under adverse conditions only flowering and fruiting pass through a series of phases during which the commitments can be adjusted downwards: reduced nut size and filling, premature nut fall, reduced fruit set, fewer pistillate flowers, smaller inflorescences and aborted inflorescences.
Thus stress affects yield much more than it affects growth. Growth can be slowed down, but the size of new leaves and roots has been fixed a long time in advance and cannot be adjusted to short-term stress periods. Inasmuch as leaf emergence slows down, this further reduces yield potential, as the emergence of the inflorescence follows the emergence of the subtending leaf.
At the rosette stage the growing point continues to enlarge until the size of the leaf initials reflects the prevailing growing conditions; then trunk formation starts. Widely spaced palms growing under favourable conditions are therefore larger than closely spaced palms or palms on poor sites. At close spacing, height growth is accelerated at the expense of flowering and fruiting.
Precocity and yield are positively correlated with annual leaf formation; hence dwarf palms yield earlier (first flowering about 2 years after germination against a minimum of 4 years for tall palms) and more than tall palms. Stem elongation begins before first flowering, but it is not clear what determines the end of the juvenile period.

Other Botanical Information

According to flowering, four categories of reproductive behaviour can be distinguished, ranging from strict allogamy (palms with short female phase without overlapping the male phase of the same or following inflorescences) to semi-direct autogamy (a long female phase overlapping the male phase of the same inflorescence as well as that of the following one). Although autogamy is possible in tall cultivars, these are usually cross-pollinating and heterogeneous. Dwarfs are usually self-pollinating and homogeneous. Pollination is by wind as well as by insects.
Coconuts can also be divided according to the shape of the nut: the Niu kafa type that evolved naturally (triangular nuts with a thick husk, thick shell and slow germination); and the Niu vai type that developed under cultivation (round nuts, thinner husk and shell, and early germination).
There are three dwarf-cultivar coconuts: the 'Niu Leka' from Fiji, differing from the tall only by its very short internodes and short rigid leaves; the medium-sized coconuts, such as the 'Malaysian Dwarf' from Indonesia, the 'Gangabondam' from India and the 'King' coconut from Sri Lanka; and the small dwarf cultivars that occur in various countries.
The 'Makapuno' from the Philippines and the 'Kelapa kopjor' from Indonesia are palms with nuts in which the endosperm almost fills the entire nut cavity. The endosperm is soft and has a peculiar taste, and is considered a delicacy. The nuts do not germinate but the embryos can be cultivated in vitro. This character may appear in any tall cultivar.

Ecology

Coconut is essentially a crop of the humid tropics. It is fairly adaptable with regard to temperature and water supply, and so highly valued that it is still common near the limits of its ecological zone. The annual sunlight requirement is estimated at above 2000 hours, with maybe a lower limit of 120 hours per month. The optimum mean annual temperature is estimated at about 27°C, with an average diurnal variation between 5 and 7°C. For good nut yields, a minimum monthly mean of 20°C is required. Temperatures below 7°C may seriously damage young coconut palms, but varietal differences exist in low temperature tolerance.
Evenly-distributed rainfall above 2000 mm and a high relative humidity are preferred, but the leaves are designed to minimize water loss and can stand drought periods of several months. Hence groundwater (for example, on coastal plains) and irrigation can replace rains, but water shortage reduces yields.
The coconut palm thrives on a wide range of soils, from coarse sand to clay, provided the soils have adequate drainage and aeration, but does best on well-drained sandy soils. It tolerates alkaline soils with pH 8 and acid soils with pH 4.5 or higher. The species tolerates saline and infertile soils as well as salt-spray conditions (Chan and Elevitch, 2006; Orwa et al., 2009).

Latitude/Altitude Ranges

Latitude North (°N)Latitude South (°S)Altitude lower (m)Altitude upper (m)
27-2501200

Air Temperature

ParameterLower limit (°C)Upper limit (°C)
Absolute minimum temperature0 
Mean annual temperature2235
Mean maximum temperature of hottest month3038
Mean minimum temperature of coldest month412

Rainfall

ParameterLower limitUpper limitDescription
Dry season duration04number of consecutive months with <40 mm rainfall
Mean annual rainfall12002300mm; lower/upper limits

Rainfall Regime

Bimodal
Uniform

Soil Tolerances

Soil texture > light
Soil texture > medium
Soil texture > heavy
Soil reaction > acid
Soil reaction > neutral
Soil drainage > free
Special soil tolerances > saline

Notes on Pests

Many diseases affect coconut. Important ones are yellowing diseases caused by mycoplasma-like organisms, such as lethal yellowing in the Caribbean, Cape St. Paul wilt, Kaincop and Kribi disease in West Africa, and lethal disease in Tanzania. Similar diseases suspected to be caused by mycoplasma-like organisms are Malaysian wilt in Malaysia, stem necrosis in Malaysia and Indonesia, Natuna wilt in Indonesia and New Hebrides disease in Vanuatu. The cultivar ‘Malaysian Dwarf' is highly tolerant of lethal yellowing but shows varying tolerances to other yellowing diseases. Talls are more susceptible. Control is by breeding for tolerance. Kerala wilt, possibly caused by a virus, is an important disease in India. Bud rot, occurring worldwide, is caused by the fungus Phytophthora palmivora and is favoured by high humidity. It causes rot of the spear and the growing point. It can be controlled by wider spacing, better aeration, drainage and weed control. Cadang cadang, a slowly spreading disease in the Philippines and the island of Guam, is caused by a viroid. Control is through resistance breeding. Basal stem rot is caused by the fungus Ganoderma orbiforme and stem bleeding is suspected to be caused by the fungus Ceratocystis paradoxa. Leaf blight is caused by Pestalotiopsis palmarum, while leaf rot or helminthosporiosis is caused by Setosphaeria rostrata and Bipolaris incurvata. These fungal diseases are widespread. White thread blight, caused by Corticium penicillatum, causes damage in Papua New Guinea.
There are also numerous pests that attack coconut. Larvae of the rhinoceros beetle (Oryctes rhinoceros) tunnel through the unopened leaves so that unfolding leaves look as if triangles have been cut out with scissors. When the growing point is attacked, the palm dies. This pest occurs widely in South-East Asia and the Pacific. Control is achieved by plantation sanitation and biological control by applying Oryctes rhinoceros virus to breeding places. Other Coleoptera causing serious damage to coconut are Promecotheca spp. in Indonesia, Malaysia and the Philippines, and Brontispa longissima in Malaysia, Indonesia and the Pacific. Larvae of the weevils Rhynchophorus ferrugineus and R. vulneratus in South Asia and Malaysia cause serious damage by boring into the coconut palm trunk. Many caterpillars feed on coconut leaves, such as Hidari irava in Indonesia; Tirathaba spp. in South-East Asia and the Pacific; Setora nitens in Malaysia, Myanmar, Vietnam and Indonesia; Parasa lepida from India to Papua New Guinea and China; and Artona catoxantha in Malaysia, Indonesia, Papua New Guinea and the Philippines. The scale insect Aspidiotus destructor is one of the most widespread pests of the coconut palm. Chemical control with an emulsion of soft laundry soap and kerosene oil in water is cheap and effective. The white fly Aleurodicus destructor sometimes causes serious damage to coconut in Indonesia and the Philippines. The nematode Bursaphelenchus cocophilus is distributed by palm weevils and is fatal to young palms; so far it is restricted to the Caribbean, Central America and northern South America.

List of Pests

This content is currently unavailable.

Non-Infectious Disorders

Genetic disorders

Several abnormalities may occur in coconut, including polyembryony, horned nuts, abnormal leaves, suckering, male coconut, female coconut, branching and variation in carpel number (IKISAN, 2016).

Physiological disorders

Button shedding (female flower shedding) and the shedding of immature nuts can occur for several reasons, including improper irrigation regimes and nutrient deficiencies (TNAU, 2014a).
Barren nuts may occur in coconuts and can be treated with extra applications of potassium oxide with borax (TNAU, 2014a). 
Finschhafen disorder, characterised by yellowing-bronzing of fronds progressing from tips towards the petiole, is now thought to be caused by the planthopper Zophiuma lobulata (Gitau et al., 2010).
Bristle top is listed as a disorder of unknown etiology by some sources (Chiarappa and Boccardo, 1980), although little information can be found about it in the literature.
Non-infectious diseases/Nutrient deficiencies

Boron deficiency

As boron is immobile within the palm and can’t move from leaf to leaf, deficiencies tend to affect only leaf primordia developing in the bud, and symptoms on newly emerging leaves remain visible as the leaves mature. Symptoms on leaves include leaf wrinkling with bent leaflet tips (hook leaf), a serrated zigzag appearance and failure to open properly when emerging from the bud. Inflorescences and nuts may become necrotic. Foliar sprays of borax can be used to reverse the disorder (TNAU, 2014b).

Calcium deficiency

This usually happens on acid soils, and symptoms include: young leaves with narrow white bands at the margins, interveinal chlorosis, rusty looking leaf margins and rolled leaves. It can be managed with soil applications of lime (based on lime requirement and root feeding of 1% calcium nitrate) (TNAU, 2014b).

Copper deficiency

Symptoms include: coppery and blueish looking leaves, rolling of terminal leaves due to loss of turgor, bleached grey leaves and failure to flower. Soil application of copper sulfate at 25 kg per ha can be used to treat this disorder (TNAU, 2014b).

Iron deficiency

May occur on poorly aerated soils or where palms have been planted too deeply. Symptoms include chlorosis between the veins of new leaves. As the disease progresses, chlorosis becomes uniform, tips may become necrotic and leaf size is reduced. The disorder can be managed with applications of iron (II) sulfate at 0.25-0.50 kg / tree / year (TNAU, 2014b).

Manganese deficiency

This is common on alkaline soils and causes new leaves to emerge chlorotic with longitudinal necrotic streaks. Later, leaflets appear withered and necrotic on all areas apart from the base of the leaflets. Severe deficiency can result in cessation of growth with emerging leaves consisting only of necrotic petiole stubs. Applying manganese sulfate to soil at 25 kg/ha may be used to treat this disorder (TNAU, 2014b).

Magnesium deficiency   

This appears as broad chlorotic bands along the margins of the oldest leaves, with leaf centres remaining green. Chlorosis starts at the tip and spreads to the base. In severe cases, tips may become necrotic. Older leaves become bronzed and dry looking, with leaflets showing necrosis and turning reddish brown with translucent spots. Soil application of magnesium sulfate at 1-2 kg/tree/year or root feeding of 0.2% magnesium sulfate twice a year can be used to treat this disorder (TNAU, 2014b).   

Molybdenum deficiency

Symptoms include chlorotic leaf blades, small thin leaves, rosetting, and whip tail. Management can include root feeding of 0.05% sodium molybdate (TNAU, 2014b).

Nitrogen deficiency

Symptoms include a uniform light green colour progressing to chlorosis in older leaves. Chlorosis spreads from tip to base in lower leaves and moves up the palm. As the deficiency progresses, young leaves may become chlorotic, older leaves become golden yellow, leaves may be shed and growth may stop. It can be treated with foliar application of 2% urea three times (at fortnightly interval) or soil application of 1-2 kg urea / tree or root feeding of 1% urea 200 ml twice a year (Vikaspedia, 2016).

Phosphorus deficiency

Deficiency occurs on acid and alkaline soils. Leaves become purple and in severe cases may turn yellow before drying prematurely. Other symptoms include: sluggish growth, leaves remaining upright, premature leaf shedding, reduced leaf growth, numbers and size, and restricted root growth. Management is by foliar spray of DAP 2% twice (at fortnightly interval) or soil application of FYM 5 kg per tree. Root feeding of 1% DAP 2 ml twice a year (Vikaspedia, 2016).

Sulfur deficiency

Symptoms include yellowish-green or yellowish-orange leaflets with older leaves remaining green, leaf drop as the stem becomes weak, and reduced leaf number and size in older palms. Sometimes an apron of dead fronds develops around the stem due to weakness of the rachis, nuts may fall prematurely, and the copra is rubbery and of poor market quality. This disorder can be corrected with soil application of gypsum 2–5 kg/tree/year. Root feeding of 0.2% gypsum (Vikaspedia, 2016).

Zinc deficiency

Leaf size is reduced up to 50%, leaflets may become chlorotic, narrow and shortened, and buttons may be shed. In severe cases, flowering may be delayed. Soil application of zinc sulfate at 25 kg/ha may be used to treat this disorder.

Pencil point disorder

This occurs as a result of micronutrient deficiencies, and causes the stem to taper towards the tip with fewer leaves. Leaf size is reduced and leaves are pale and yellow. If caught early, the disorder can be corrected with the soil application of a fertilizer containing borax, zinc sulphate, manganese sulphate, ferrous sulphate, copper sulphate and ammonium molybdate.      

Impact Summary

CategoryImpact
Cultural/amenityPositive and negative
Economic/livelihoodPositive and negative
Environment (generally)Positive and negative
Human healthPositive and negative

Impact: Environmental

C. nucifera is considered one of the most successful plants colonizing new habitats. C. nucifera is a common component of many tropical and subtropical island and coastal ecosystems around the world (Chan and Elevitch, 2006; Orwa et al., 2009; Young et al., 2010). In coastal areas where C. nucifera becomes dominant, it has been suggested that this species may have negative impacts on floristic, structural and soil characteristics of coastal native forests (Kairo et al., 2003; Young et al., 2010; Oviedo Prieto et al., 2012). For example, in the coastal forest of the Palmyra Atoll in the Northern Pacific, the high abundance of coconut plants has been associated with lower diversity of native plants and regenerating understory, lower abundance of major macronutrients and lower energy content of soil organic matter (Young et al., 2010).  

Risk and Impact Factors

Invasiveness

Proved invasive outside its native range
Has a broad native range
Abundant in its native range
Highly adaptable to different environments
Capable of securing and ingesting a wide range of food
Highly mobile locally
Benefits from human association (i.e. it is a human commensal)
Long lived
Fast growing

Impact outcomes

Altered trophic level
Damaged ecosystem services
Ecosystem change/ habitat alteration
Modification of nutrient regime
Modification of successional patterns
Monoculture formation
Reduced native biodiversity

Impact mechanisms

Causes allergic responses
Competition - smothering
Pest and disease transmission
Rapid growth

Likelihood of entry/control

Highly likely to be transported internationally deliberately

Uses

C. nucifera has been called the ‘tree of life’ or ‘tree of heaven’ because of its value as provider of so many useful products. This species provides food, water, oil, medicine, fibre, timber, and fuel for many people living on islands in the Pacific Ocean (Chan and Elevitch, 2006). High quality coconut oil is used for cooking or in the manufacture of margarine, shortening, filled milk and ice cream. Coconut oil is also processed into soap, detergents, cosmetics, shampoos, paints, varnishes and pharmaceutical products. Remnant fatty acids and alcohols and their methyl esters find application as components of emulsifiers and surfactants.
The press cake or copra meal is a good livestock feed. Coconut milk or cream pressed from the mix of freshly grated endosperm has been a traditional ingredient in many African and especially Asian food and bakery products. It is now also marketed in pasteurized and homogenized canned or powdered form. Water in the cavity of young coconuts is consumed as a cool and sweet-tasting, popular refreshment. It is now also commercially preserved without altering its typical flavour. The tender, jelly-like endosperm of young coconuts is a delicacy consumed directly or grated and mixed with food. The palm heart, which consists of the white, tender tissues of the youngest, unopened leaves at the stem apex, is also considered a delicacy.
The shell (endocarp) covering the seed can be made into household utensils and decorated pots, converted into shell charcoal (suitable for activation) or used as fuel. Finely ground coconut shell is used as filler for resin glues and moulding powders.
Green husks (mesocarp) are used for making ropes, carpets, mats and textiles. Brown coir from husks of mature fruits is used in brushes (long bristle fibres), mattresses, upholstery and particle board (short fibres), and as a soil/potting mix amendment.  
A sweet sap containing about 15% sucrose is tapped from unopened inflorescences and is transformed into a light alcoholic wine when fermented. A by-product of palm wine is vinegar.  Boiling fresh sap yields palm syrup and sugar. Distillation of palm wine yields a potent alcoholic beverage called ‘arak’.  
The leaves are used to thatch roofs; the leaflets are plaited into mats, baskets, bags and hats; immature leaflets are made into traditional decorations and small bags or containers for food; the midribs of the leaflets are formed into brooms.
The wood of old palms is used for furniture, light constructions, household utensils and tool handles. The wood is very hard. It can be sawn with special tungsten carbide-tipped saw blades. It should be sawn when fresh. Preservative treatment of the sawn lumber is indispensable if it is to be used for building construction or any outdoor use.
Medicinal uses have also been attributed to coconut palm. The roots are considered antipyretic and diuretic. Milk of young coconut is diuretic, laxative and antidiarrheal. The oil is used to treat diseased skin and teeth.
Coconut palms have ornamental value and are often planted as ornamentals and windbreak plants in resorts, beaches, gardens and coastal parks. They are also planted as shade-trees in taro, cocoa and coffee plantations (Duke, 1983; Chan and Elevitch, 2006; Orwa et al., 2009; PROTA, 2014).

Uses List

General > Sociocultural value
General > Ornamental
Environmental > Agroforestry
Environmental > Boundary, barrier or support
Environmental > Erosion control or dune stabilization
Environmental > Landscape improvement
Environmental > Windbreak
Materials > Baskets
Materials > Carved material
Materials > Cosmetics
Materials > Essential oils
Materials > Fibre
Materials > Gum/resin
Materials > Miscellaneous materials
Materials > Oils
Materials > Wood/timber
Medicinal, pharmaceutical > Source of medicine/pharmaceutical
Medicinal, pharmaceutical > Traditional/folklore
Fuels > Charcoal
Fuels > Fuelwood
Human food and beverage > Beverage base
Human food and beverage > Food additive
Human food and beverage > Fruits
Human food and beverage > Nuts
Human food and beverage > Oil/fat
Animal feed, fodder, forage > Fodder/animal feed
Animal feed, fodder, forage > Forage

Wood Products

Boats
Charcoal
Containers > Boxes
Containers > Crates
Furniture
Roundwood > Building poles
Roundwood > Posts
Roundwood > Transmission poles
Sawn or hewn building timbers > Carpentry/joinery (exterior/interior)
Sawn or hewn building timbers > Fences
Sawn or hewn building timbers > Flooring
Sawn or hewn building timbers > For light construction
Sawn or hewn building timbers > Gates
Wood-based materials > Laminated veneer lumber
Wood-based materials > Laminated wood
Wood-based materials > Particleboard
Woodware > Industrial and domestic woodware
Woodware > Tool handles
Woodware > Wood carvings

Agronomic Aspects

Propagation and PlantingCoconut has always been propagated by 'seed'. In 1982 the first clonal plant was produced by tissue culture. The method is still being improved. In-vitro culture of coconut embryos is possible, which is important for seed transport and solves quarantine problems.Seed nuts are usually given a resting period of 1 month after harvesting. Then they are kept in a germination bed from where uniform batches can be transplanted to polythene bags or to nursery beds. The polybag method, including regular fertilization, has largely replaced the bare-root seedlings raised in beds. Seedlings are transplanted at the age of 3-8 months. In the nursery bed seedlings can be kept longer, but suffer greater shock when transplanted.Where inter-tree competition is manifest, growth is maintained at the expense of flowering and fruiting. Growers therefore prefer to err on the wide side in spacing the palms. The open crowns transmit a fair portion of incident light; in combination with generous spacing this means that coconut is well suited to intercropping. Intercropping with crops which exploit different soil levels may be expected to result in more efficient fertilizer use. Intercropping, especially with perennials, may stabilize soil temperature, protect the soil surface from rain impact, produce more organic matter and increase soil ecologic life in the root zone. It also creates an atmosphere favourable for a more varied insect population, thus creating a better natural balance. Catch crops are often planted until the palms come into bearing. These include rice, maize, finger millet, sweet potato, cassava and other food crops. These crops should not be planted closer than 2 m to the palms. Intercropping with banana and pineapple is practised in some areas. Coconut is occasionally grown with tree crops (for example, cocoa, rubber, mango, cashew), but this is usually considered to result in lower yields of copra. In humid climates, cocoa is one of the best intercrops. In Malaysia, under favourable conditions yields of more than 1000 kg/ha of dry cocoa beans have been obtained from cocoa grown under coconuts on good soils. Pastures are sometimes established under the palms for use in mixed husbandry. Green manures are occasionally planted. Pastures and cover crops can only be grown when there is sufficient rain.Coconut is planted mostly at spacings of 8 x 8 to 9 x 9 m, triangular or square. Dwarf cultivars are planted at a spacing of 7.5 x 7.5 m. Hedge planting may be used to facilitate intercropping, but the radial symmetry of the leaf arrangement does not tolerate extreme forms of row cropping.HusbandryWeeding is essential, especially for young palms. Green manuring is often practised to advantage. Fertilizing is often required, especially on soils that have been cultivated for many years. Smallholders seldom apply fertilizers. The effect of manuring and other cultural practices on yield are not apparent until after 2.5-3 years, the period required for development from the primordia to the ripe nuts, although a general improvement in the condition of the trees may be visible within 1 year. Potassium is the predominant nutrient requirement of the palm, followed by nitrogen and phosphorus. Foliar leaf analysis is a guide to fertilizer requirements. The amount of nutrients removed by a good crop of 7500 nuts/ha if the husks are not returned is N 67 kg, P2O5 22 kg and K2O 90 kg. A typical fertilizer mixture recommended per palm is N 0.2-0.3 kg, P2O5 0.2-0.3 kg, K2O 0.5- 0.7 kg, given in split applications at the beginning and end of the rains in a band encircling the palm up to 1.5-2 m from the trunk.Irrigation is sometimes practised in dry areas where water is available. Occasional inundations with sea water do not harm the palm, provided the soil salt content does not rise too high. The cumulative income from well fertilized coconut and intercrop often is much higher than that of the coconut alone. Mechanization is practised only on large estates.HarvestingClimbing the palms and cutting the coconuts is still the method most commonly practised at harvesting. Reaping of fallen nuts is easier, but more nuts are lost due to rat attack and theft, and some nuts may germinate on the tree. In some countries such as Malaysia, Indonesia and Sri Lanka, bamboo poles about 25 m long with a knife attached to the end are sometimes used to cut the ripe bunches. In some regions of Malaysia, Thailand and Indonesia the monkey Macacus nemestrina is trained to harvest ripe nuts.YieldYields of coconut plantations vary widely. Smallholder plantations usually yield between 0.5-1.0 t of copra per ha. In Malaysia, estate yields are estimated at about 1.5 t/ha of copra, and the potential yield at 3.5 t/ha. From well-managed plantations of selected local talls in Indonesia, yields of 3.5-4.5 t/ha of copra have been reported. Average yields of dwarf plantations on estates in Malaysia have been estimated at about 1.5-2.0 t/ha, but under favourable conditions the yielding potential may be 3.5 t. The dwarf x tall hybrid combines the high number of nuts produced by the dwarf with the larger nut size from the tall and usually has a higher yielding potential than its parents. From an experimental station in Côte d'Ivoire, yields of more than 6 t/ha have been reported. Over a 10 year period yields of 800 to 1000 nuts have been reported from well-husbanded palms.Handling after HarvestHarvested nuts are transported to a kiln, where they are stored until the husks are completely dry. After drying the nuts are dehusked manually by striking and twisting them on a steel point that is placed firmly in the ground. Mechanical dehusking has been tried with little success, but a new device under development in Venezuela shows promise. After dehusking, the nuts are split with a machete and the water is drained. The nut halves are placed in a kiln and dried for 1-2 days, after which the endosperm is scooped out from the shell and dried further until the moisture content is about 6%. Sun-drying is also possible but has a higher risk of deterioration of the product, especially in humid seasons and rainy periods. The copra obtained is sent to the oil mills. Coconuts are also sold to desiccation factories. There the shell and the brown testa are pared off, the white endosperm is washed, pasteurized, shredded into small particles, and dried.

Silviculture Characteristics

Tolerates > wind
Tolerates > salt wind
Ability to > self-prune

Silviculture Practice

Seed storage > recalcitrant
Seed storage > intermediate
Vegetative propagation by > tissue culture
Stand establishment using > natural regeneration
Stand establishment using > direct sowing

Cultivation

Planting stock production

Seed nuts are usually given a resting period of 1 month after harvesting. Then they are kept in a germination bed from where uniform batches can be transplanted to polyethylene bags (‘polybags’) or to nursery beds. The polybag method, which includes regular fertilization, has largely replaced bare-root seedling production in beds. Seedlings are transplanted to plots at the age of 3-8 months. In the case of nursery bed seedlings, they can be kept longer but suffer greater shock when transplanted.

Cropping systems

Where inter-tree competition is manifest, growth is maintained at the expense of flowering and fruiting. Growers therefore prefer to err on the wide side in spacing palms. The open crowns transmit a fair portion of incident light; in combination with generous spacing, this means that coconut is well suited to intercropping. Intercropping with crops which exploit different soil levels may be expected to result in more efficient fertilizer use. Intercropping, especially with perennials, can stabilize soil temperature, protect the soil surface from rain impact, produce more organic matter and increase soil biota in the root zone. It also creates an atmosphere favourable for a more varied insect population, thus creating a better natural balance. Catch crops are often planted until the palms start bearing. These include rice, maize, finger millet, sweet potato, cassava and other food crops. These crops should not be planted closer than 2 m to the palms. Intercropping with banana and pineapple is practised in some areas. Coconut is occasionally grown with tree crops such as cocoa, rubber, mango and cashew, but this is usually considered to result in lower yields of copra. In humid climates, cocoa is one of the best intercrops. In Malaysia, under favourable conditions yields of more than 1000 kg/ha of dry cocoa beans have been obtained from cocoa grown under coconuts on good soils. Pastures are sometimes established under palms for use in mixed husbandry. Green manures are occasionally planted. Pastures and cover crops can only be grown when there is sufficient rain. The cumulative income from well fertilized coconut and intercrop often is much higher than that of coconut alone.

Cultural requirements

Coconut palms are planted mostly at spacings of 8 x 8 to 9 x 9 m, in triangular or square planting patterns. Dwarf cultivars are planted at a spacing of 7.5 x 7.5 m. Hedge planting may be used to facilitate intercropping, but the radial symmetry of the leaf arrangement does not tolerate extreme forms of row cropping.
Weeding is essential, especially for young palms, and green manuring is often practised. Fertilizers are often required, especially on soils that have been cultivated for many years, although smallholders seldom apply them. The effects of manuring and other cultural practices on yield are not apparent until after 2.5-3 years, the period required for nut development (from primordia to ripe nuts), although a general improvement in the condition of the trees may be visible within 1 year. Potassium is the predominant nutrient requirement of the palm, followed by nitrogen and phosphorus. Foliar leaf analysis is a guide to fertilizer requirements. The amount of nutrients removed by a good crop of 7500 nuts/ha if the husks are not returned is 67 kg N, 22 kg P2O5 and 90 kg K2O. A typical fertilizer mixture recommended per palm is 0.2-0.3 kg N, 0.2-0.3 kg P2O5 and 0.5- 0.7 kg K2O, given in split applications at the beginning and end of the rains in a band encircling the palm up to 1.5-2 m from the trunk.
Irrigation of coconut palms is sometimes practised in dry areas where water is available. Occasional inundations with sea water do not harm the palm, provided the soil salt content does not rise too high.
Mechanization is practised only on large estates.

Harvesting

Harvesting

Fruits require about a year to mature, and harvesting can be done regularly throughout the year. Harvesting coconut fruits can be a risky undertaking. If fruits must not be entirely ripe, they have to be removed from the often very tall trees. It may be done by climbers who use the roughness left by old leaf-bases on the stem, to climb to the top. They are usually attached to the trunk with a rope. In some countries such as Malaysia, Indonesia and Sri Lanka, bamboo poles about 25 m long with a knife attached to the end are sometimes used to cut the ripe bunches. In some regions of Malaysia, Thailand and Indonesia macaque monkeys (Macaca nemestrina) are trained to harvest ripe nuts. If fruits are required entirely ripe, the fruits will be left to fall naturally.
Climbing the palms and cutting the coconuts is still the method most commonly practised at harvesting. Gathering of fallen nuts is easier, but more nuts are lost due to rat attack and theft, and some nuts may germinate on the tree.

Yield

Yields from coconut trees and plantations vary widely. On very fertile land, a tall palm may produce up to 75 nuts per year, but more often yields are less than 30 nuts per tree due to poor cultural practices. Over a 10-year period, yields of 800-1000 nuts have been reported from well-husbanded palms.
Where coconut is grown for copra, smallholder plantations usually yield between 0.5 and 1.0 t copra per ha. In Malaysia, estate yields are estimated at about 1.5 t copra per ha, with a potential of 3.5 t/ha. From well-managed plantations of selected local Tall varieties in Indonesia, copra yields of 3.5-4.5 t/ha have been reported. Average yields from Dwarf plantations on estates in Malaysia have been estimated at about 1.5-2.0 t/ha, but around 3.5 t/ha under favourable conditions. Dwarf x Tall hybrids combine the high number of nuts produced by the Dwarf parent with the larger nut size of the Tall, and usually have a higher yield potential than either parent. From an experimental station in Côte d'Ivoire, yields of more than 6 t/ha have been reported.

Postharvest Treatment

Postharvest treatment

Harvested nuts destined for copra production are transported to a kiln, where they are stored until the husks are completely dry. After drying the nuts are dehusked manually by striking and twisting them on a steel point that is placed firmly in the ground. Various mechanical dehusking machines have been developed and tried with differing levels of success. After dehusking, the nuts are split with a machete and the water is drained. The nut halves are placed in a kiln and dried for 1-2 days, after which the endosperm is scooped out from the shell and dried further until the moisture content is about 6%. Sun-drying is also possible but has a higher risk of deterioration of the product, especially in humid seasons and rainy periods. The copra obtained is sent to oil mills. Coconuts are also sold to desiccation factories. There the shell and the brown testa are pared off, the white endosperm is washed, pasteurized, shredded into small particles and dried.
For the fresh market, the quality of harvested coconuts is affected mainly by maturity, size and freedom from blemishes, cracking, fibre when husked, and wet or mouldy eyes. There are no specific grades, but informal grades are usually based on size and weight. Mature US dehusked coconuts are sold in 34-36 kg woven plastic or burlap sacks containing 40-50 coconuts, plastic mesh bags of 12 coconuts or 17-18 kg cartons with 20-25 film-wrapped coconuts. After the husk is partially removed from immature coconuts in South-East Asia, they are shaped, dipped in a 1-3% sodium metabisulfite solution, film wrapped, and sold in single-piece cartons containing 10-16 nuts. Alternatively, the whole husk is removed and the coconuts dipped in sodium metabisulfite before packing. The chemical, however, is not approved in the USA for this purpose.

Storage

When storing coconuts, room cooling is most often used for mature husked nuts, though the nuts can be forced-air or hydro-cooled. Rapid temperature changes of 8°C can cause cracking of mature coconuts. Mature coconuts with husk can be kept at ambient conditions for 3-5 months before the coconut water has evaporated, the shell has cracked because of desiccation or sprouting has occurred. Storage at 0-1.5°C and 75–85% relative humidity (RH) is possible for up to 60 days for mature dehusked coconut and 13-16°C and 80–85% RH for 24 weeks. Low humidity and high temperature are to be avoided. Immature nuts have green skins that turn brown after 7 days at 0°C. Young coconuts are normally held at 3–6°C and 90-95% RH, and husked-wrapped, shaped fruit can be held for 3-4 weeks. Shaped young coconuts go brown in 12 h, but when treated with a 0.5–1.0% sodium metabisulfite solution they can be held at ambient temperature for 2 days before browning occurs, and if treated with 2% sodium metabisulfite can be held at ambient temperature for 2-7 days. Young coconuts that are not dehusked can be stored for up to 28 days at 17°C, as the husk acts as an insulator and appears to increase storage life.
Principal sources: Janick and Paull (2008)

Genetic Resources and Breeding

Genetic Resources

Because coconut is mainly a smallholder's crop, for a long time little attention has been given to research in methods of cultivation, germplasm collections and registration of cultivars. Local cultivars are usually heterogeneous populations with some predominating characteristics. Cultivars with different names growing in different areas are sometimes rather similar and may be of the same origin. Small germplasm collections can be found in several research stations around the world. In 1978, the International Board for Plant Genetic Resources (IBPGR) accepted a minimum list of descriptors to be used in collecting germplasm in the field. In 1980 the IBPGR supported the survey and collection of coconut germplasm in priority areas in South-East Asia. In 1980 it provided funds for the collection of coconuts in the Indonesian Archipelago, for the establishment of a coconut germplasm centre in the Philippines, and for the collection of germplasm in the Pacific to be planted on one of the Andaman Islands to screen for Kerala wilt disease resistance on mainland India.

Breeding

For a long time, breeding consisted mainly of mass selection and line breeding of tall coconuts. In northern Sulawesi, Indonesia, very good results were obtained; some palms of the third generation yielded up to almost 45 kg of copra per palm. Nowadays most of the attention is given to the breeding of dwarf x tall hybrids. The selection and breeding of talls and dwarfs as such does not receive sufficient attention.

Major Cultivars

For coconuts, the terms variety, cultivar, ecotype and population are often used interchangeably, but Latinized distinctions between typica for tall cultivars and nana for dwarf cultivars are less useful than the system of naming types according to their origin and habit (e.g., ‘Jamaica Tall’), sometimes with fruit colour added (e.g., ‘Malayan Yellow Dwarf’). Tall cultivars tend to be slower to begin flowering and are generally (but not always) cross-pollinated, while dwarf cultivars are generally (but not always) self-pollinated. Dwarf cultivars are more precocious and the first fruits may be produced at or close to ground level – hence the terminology ‘dwarf ’. Although they are never as tall or as vigorous as tall cultivars, they can reach 30 m in 60 years. The colours green, red and yellow seen in the petioles and fruit serve to differentiate between blocks of self-pollinated dwarf populations but are less obvious in cross-pollinated tall populations, which tend to be mixtures of green- and bronze-coloured individuals. However, colours help to identify off-types when hybrids are produced between yellow dwarf seed parents and tall pollen parents. Commercially, dwarf cultivars are considered to be less productive, more sensitive to poor conditions and produce lower quality copra. Some dwarf cultivars are more resistant to serious virus and phytoplasma diseases than tall cultivars.
Of the population types, one of the most interesting for fresh or green coconut use is the macapuno type. Whereas the mature normal endosperm is hard and compact around the periphery of the cavity, in the macapuno type it is soft and curd-like, filling the entire cavity. The endosperm cells of macapuno coconut are large and multinucleate, with low intercellular adhesion, and cytokinin activity is higher than in non-macapuno nuts. Macapuno endosperm has reduced hemicellulose content in the cell walls and a different cell wall sugar composition. Types similar to the Philippine macapuno have been reported in India as ‘Thairu thengai’, in Sri Lanka as ‘Dikiri’, in Thailand as ‘Maphrao Kathi’, in Indonesia as ‘Korpyor’, and as ‘Dua Dac Ruot’ in Vietnam. The macapuno character is probably conditioned by a single recessive gene, hence homozygous palms need to be grown in isolation to ensure 100% yield of macapuno. Dwarf types have been selected from this normally tall type. However, the nuts do not sprout, although the embryo, once removed from the nut and washed free of endosperm, can be grown aseptically in vitro.
Another variant is ‘Nam Hom’, a fragrant dwarf cultivar that smells like pandanus leaf; it was produced in Thailand and is now used for export. The water in ‘Nam Hom’ is not as sweet as that of another Thai dwarf variety, Nam Wan, which has 6.5-7.0% total soluble solids at the green stage. In Sri Lanka, the cultivar Tembili (King Coconut) has sweeter water and is grown for drinking only.
Increased yield of copra per unit area, followed by disease resistance and fresh market quality have been the main aims of coconut breeding programmes. Successful hybrids between dwarf and tall types include ‘Maypan’ (‘Malayan Dwarf’ x ‘Panama Tall’), ‘Mawa’ (‘Malayan Yellow Dwarf’ x ‘West African Tall’) and ‘Maren’ (‘Malayan Red Dwarf’ x ‘Rennel Tall’). ‘Maypan’ was produced for planting in areas subjected to lethal yellowing disease and, like ‘Mawa’, achieves higher yields through early bearing and increased number of nuts and, like ‘Maren’, has satisfactory fruit size.
Principal sources: Janick and Paull (2008)

Propagation

Coconut has always been propagated by 'seed'. Mother palms should be selected on the basis of performance (a high number of good-sized fruit) over 3 years or longer. Fruits (seed nuts) are best reaped when the fresh skin colour is just starting to turn brown and while they contain adequate liquid and can be heard to ‘splash’ when shaken. Immature fruits (full of water and very heavy) or over-mature fruits (with no water and very light) should be rejected. The selected seed nuts can withstand normal harvesting but careful handling should avoid damage and consequential loss of viability. Setting in a nursery should take place immediately since germination can occur during storage, resulting in twisted and deformed shoots.
In 1982 the first clonal plant was produced by tissue culture. The method is still being improved. In vitro culture of excised coconut embryos is possible, which is important for reducing the handling and transport of the relatively large and heavy seed nuts, and can potentially solve quarantine problems.
Principal sources: Janick and Paull (2008)

Nutritional Value

The fresh kernel (28% whole nut) contains 25-44% oil, 35-62% water, 9-14% carbohydrates, about 5 mg/100 g vitamin C, as well as vitamins B1, B2 and B3, and minerals. The juicy, jelly-like endosperm in young coconuts is highly prized for eating out of the shell, for the water and for use in cooking. In immature (‘green’) coconuts, harvested 7-9 months after pollination, the epidermis is uniformly fresh in colour (shades of green, brown, red or yellow depending on variety) and smooth, while the coir is white. The dehusked fruit is about 10 cm in diameter and weighs about 500 g, having 100 g endosperm, 120 g shell and 250 g liquid endosperm (coconut water). The liquid endosperm in fresh ‘green’ coconuts can have 130–620 ml water and 48 g/kg sugar, depending on the stage of harvest, and is at a maximum 7-8 months after anthesis. The water is marketed in sterilized long-life packs.
Coconut oil from copra becomes solid at temperatures below about 25°C and was used as ‘vegetable butter’ until the hydrogenation process for making margarine from other vegetable oils was developed in the 1890s.
Numerous recipes exist for the use of coconut in breads, waffles, cakes, sweets, cookies, pies, ice cream, soup and other main-course cooked dishes, and the health benefits of dietary coconut oil are becoming better known. In the Philippines, acetic acid bacteria produce a ‘cartilaginous’ material from coconut water called nata de coco that is used in a number of desserts. Unopened coconut inflorescences are tapped and the exudate, known as toddy, collected and fermented to a palm wine of up to 12–13% alcohol content. It is also distilled to produce a ‘whisky’ known as arak. Alternatively, the toddy is boiled down to produce a treacle or sugar. Freshly gathered toddy has about 8.6% total soluble solids, pH 3.6, 0.23% crude protein, 0.6% sucrose, 5.7% reducing sugars and can have about 5% alcohol depending upon collection frequency and hence the time allowed for fermentation to occur. Another product is coconut milk, which is obtained mainly by pressing the grated white kernel or by passing hot water or milk through grated coconut to extract the oil and aromatic compounds. It has a fat content of 20-22%.
Principal sources: Janick and Paull (2008)

Phytosanitary Issues/Food Safety

Phytosanitary issues

Domestic quarantine is important in India to prevent the spread of root wilt disease that occurs in Kerala, India (Thomas et al., 2015).
Brontispa longissima is a serious pest of coconuts, and diagnostic techniques are being developed to discriminate between it and similar pests for quarantine purposes (Zhang et al., 2015). 
Aspidotus destructor is severe pest of coconuts in the Philippines, so that the crop and its products cannot be brought out of affected areas (Ranada, 2014).
Potential quarantine pests of coconut are listed by Diekmann (2013) as: coconut cadang-cadang viroid (CCCVd), Coconut foliar decay virus (CFDV), lethal yellowing phytoplasmas, Marasmiellus cocophilus fungus and rhinoceros beetle (Oryctes rhinoceros). O. rhinoceros is listed as a quarantine pest in the Caribbean, Central America, the Pacific and Brazil (EPPO, 2016). Regulations are in place in the USA to ensure set procedures are followed during O. rhinoceros surveys and control programs (USDA, 2015).

Food safety

Coconut can cause anaphylaxis, although this is thought to be relatively rare (Anaphylaxis, 2015).
Contamination of coconut water with moulds, yeasts, faecal coliforms and thermotolerants has been linked to poor sanitary conditions during handling and storage in Brazil (Guarnieri et al., 2015).
Processed coconut products imported to the USA from Asia have been found to be contaminated with Vibrio cholera, Salmonella spp., and Listeria spp. (FDA, 2016).
The mycotoxins aflatoxin B1 and ochratoxin A have been detected at levels of 15-25 and 50-205 µg/kg, respectively, in some samples of coconuts in Egypt (Zohri and Saber, 1993).

Production and Trade

Owing to the considerable home consumption by smallholders, production figures can be no more than estimates. In 2013, FAO estimated total world production at about 51.6 million t of nuts. Of this, Asia produced about 83.6% and Africa, Oceania and the Americas produced about 3.3, 4.7 and 8.4%, respectively. Major producers were Indonesia (18.3 m.t.), the Philippines (15.4 m.t.), India (11.9 m.t.), Brazil (2.9 m.t.) and Sri Lanka (2.5 m.t.). The Philippines export more than 90% of their coconut products, whereas in densely populated Indonesia almost all coconut products are for the home market. Papua New Guinea has become a major exporter of coconut products, having almost no home market.
Before the First World War, coconut oil was the most important vegetable oil. It now occupies sixth position, after soyabean oil, palm oil, sunflower seed oil, groundnut oil and cottonseed oil. Being a lauric oil, it still has a special position because there are only two other lauric oils on the market, palm-kernel oil and babassu oil.
See FAOStat for latest production statistics.
Markets &amp; Marketing

Quality standards and requirements

Nearly 50% of world coconut production is processed into copra. However, due to increased competition from oil palm (Elaeis spp.), the production and export of fresh coconuts is becoming more lucrative. To enter the fresh market chain, mature nuts are dehusked before shipment. The dry nuts should be brown, free from fibre, damage and cracks and of the required weight or size (35 to 45 cm in circumference). The nuts are shipped in sacks or cardboard cartons. Postharvest stress cracks are directly related to coconut weight loss. Waxing of the nuts minimizes water loss and dramatically reduces fruit cracking. The shelf life is 23 months at 12°C before the residual liquid has evaporated or the shell has cracked because of desiccation. Low humidity and high temperature must be avoided.

Markets

Coconuts are produced in 92 countries worldwide on about 11.8 million ha.
Approximately 279,000 t of desiccated coconut was traded on the world market in 2008, dominated by the Philippines, Sri Lanka and Indonesia, with the Philippines accounting for 34% of world exports. The major importers were the USA and Europe, accounting for 11% and 13% of total world imports, respectively. The product is high value and captures a higher price than copra and coconut oil.
Now that the coconut is considered a healthy food, there is a shift in the market towards high-value food uses such as tender coconut water, coconut milk, spray dried coconut milk, coconut vinegar and virgin coconut oil. Although this would put added pressure on supplies, it should serve to strengthen coconut prices to the benefit of the grower and serve as an incentive to continue and expand production (UNCTAD, 2015).
Principal sources: Janick and Paull (2008)

Prospects

In rural areas, coconut will maintain its important position because it grows under conditions where other food crops often do not perform well and because it produces so many products used by local households. On the world market, coconut will suffer more and more from the competition of palm-kernel oil and from the mechanized production of oil seeds such as soyabeans. Increases in oil-palm area will lead to a saturation of the lauric oil market and lauric oils will increasingly enter into free competition with other oils. Coconut can only maintain its position on the world market if commercial plantations are established from the best plant material available and managed at optimal levels. Intercropping could be an important factor for obtaining maximum returns from coconut plantations.

Bibliography

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