Cocos nucifera L.
Source: James A. Duke. 1983. Handbook of Energy Crops. unpublished.
- Folk Medicine
- Yields and Economics
- Biotic Factors
- Chemical Analysis of Biomass Fuels
Coconut is one of the ten most useful trees in the world, providing food for
millions of people, especially in the tropics. At any one time a coconut palm
has 12 different crops of nuts on it, from opening flower to ripe nut. At the
top of the tree is the growing point, a bundle of tightly packed, yellow-white,
cabbage-like leaves, which, if damaged, causes entire tree to die, but if tree
can be spared, this heart makes a tasty treat, a 'millionaire's salad'.
Unopened flowers are protected by sheath, often used to fashion shoes, caps,
even a kind of pressed helmet for soldiers. Opened flowers provide a good
honey for bees. A clump of unopened flowers may be bound tightly together,
bent over and its tip bruised. Soon it begins to 'weep' a steady dripping of
sweet juice, up to a gallon per day. It contains 16-30 mg ascorbic acid/100 g.
The cloudy brown liquid is easily boiled down to syrup, called coconut
molasses, then crystalized into a righ dark sugar, almost exactly like maple
sugar. Sometimes it is mixed with grated coconut for candy. Left standing, it
ferments quickly into a beer with alcohol content up to 8%, called 'toddy' in
India and Sri Lanka; 'tuba' in Philippines and Mexico; and 'tuwak' in
Indonesia. After a few weeks, it becomes a vinegar. 'Arrack' is the product
after distilling fermented 'toddy' and is a common spirituous liquor consumed
in the East. Nut has a husk, which is a mass of packed fibers called coir,
which can be woven into strong twine or rope, and is used for padding
mattresses, upholstery and life-preservers. Fiber resistant to sea water and
is used for cables and rigging on ships, for making mats, rugs, bags, brooms,
brushes, and olive oil filters in Italy and Greece; also used for fires and
mosquito smudges. If nut is allowed to germinate, cavity fills with a spongy
mass called 'bread' which is eaten raw or toasted in shell over fire.
Sprouting seeds may be eaten like celery. Shell is hard and fine-grained, and
may be carved into all kinds of objects, as drinking cups, dippers, scoops,
smoking pipe bowls, and collecting cups for rubber latex. Charcoal used for
cooking fires, air filters, in gas masks, submarines, and cigarette tips.
Shells burned as fuel for copra kilns or housefires. Coconut shell flour used
in industry as filler in plastics. Coconut water is produced by a 5 month old
nut, about 2 cups of crystal clear, cool sweet (invert sugars and sucrose)
liquid, so pure and sterile that during World War II, it was used in
emergencies instead of sterile glucose solution, and put directly into a
patient's veins. Also contains growth substances, minerals, and vitamins.
Boiled toddy, known as jaggery, with lime makes a good cement. Nutmeat of
immature coconuts is like a custard in flavor and consistency, and is eaten or
scraped and squeezed through cloth to yield a 'cream' or 'milk' used on various
foods. Cooked with rice to make Panama's famous 'arroz con coco'; also cooked
with taro leaves or game, and used in coffee as cream. Dried, desiccated, and
shredded it is used in cakes, pies, candies, and in curries and sweets. When
nuts are cut open and dried, meat becomes copra, which is processed for oil,
rich in glycerine and used to make soaps, shampoos, shaving creams, toothpaste
lotions, lubricants, hydraulic fluid, paints, synthetic rubber, plastics,
margarine, and in ice cream. In India, the Hindus make a vegetarian butter
called 'ghee' from coconut oil; also used in infant formulas. When copra is
heated, the clear oil separates out easily, and is made this way for home use
in producing countries. Used in lamps. Cake residue used as cattle fodder, as
it is rich in proteins and sugar; should not give more than 4-5 lbs/animal/day,
as butter from milk will have a tallow flavor. As cake is deficient in
calcium, it should be fed together with calcium rich foods. Trunk wood used
for building sheds and other semi-permanent buildings. Outer wood is
close-grained, hard, and heavy, and when well seasoned, has an attractive dark
colored grain adaptable for carving, especially ornamentals under the name of
'porcupine wood'. Coconut logs should not be used for fences, as decayed wood
makes favorable breeding places for beetles. Logs are used to make rafts.
Sections of stem, after scooping out pith, are used as flumes or gutters for
carrying water. Pith of stem contains starch which may be extracted and used
as flour. Pitch from top of tree is sometimes pickled in coconut vinegar.
Coconut leaves made into thin strips are woven into clothing, furnishings,
screens, and walls of temporary buildings. Stiff midribs make cooking skewers,
arrows, brooms, brushes, and for fish traps. Leaf fiber used in India to make
mats, slippers, and bags. Used to make short-lived torches. Coconut roots
provide a dye, a mouthwash, a medicine for dysentery, and frayed out make
toothburshes; scorched, used as coffee substitute. Believed to be
antiblenorrhagic, antibronchitis, febrifugal, and antigingivitic. Coconut palm
is useful as an ornamental; its only drawback being the heavy nuts which may
cause injury to man, beast, or rooftop when they hit in falling (Duke, 1972).
According to Hartwell (1967-1971) coconuts are used in folk remedies for
tumors. Reported to be anthelmintic, antidotal, antiseptic, aperient,
aphrodisiac, astringent, bactericidal, depurative, diuretic, hemostat,
pediculicide, purgative, refrigerant, stomachic, styptic, suppurative, and
vermifuge, coconut, somewhere or other, is a folk remedy for abscesses,
alopecia, amenorrhea, asthma, blenorrhagia, bronchitis, bruises, burns,
cachexia, calculus, colds, constipation, cough, debility, dropsy, dysentery,
dysmenorrhea, earache, erysipelas, fever, flu, gingivitis, gonorrhea,
hematemesis, hemoptysis, jaundice, menorrhagia, nausea, phthisis, pregnancy,
rash, scabies, scurvy, sorethroat, stomach, swelling, syphylis, toothache,
tuberculosis, tumors, typhoid, venereal diseases, and wounds (Duke and Wain,
Per 100 g, the kernel is reported to contain 36.3 g H2O 4.5 g protein, 41.6 g
fat, 13.0 g total carbohydrate, 3.6 g fiber, 1.0 g ash, 10 mg Ca, 24 mg P, 1.7
mg Fe, and traces of beta-carotene (C.S.I.R., 1948-1976). Per 100 g, the green
nut is reported to contain 77-200 calories, 68.0-84.0 g H2O, 1.4- 2.0 g
protein, 1.9-17.4 g fat, 4.0-11.7 g total carbohydrate, 0.4-3.7 g fiber,
0.7-0.9 g ash, 11-42 mg Ca, 42-56 mg P, 1.0-1.1 mg Fe, 257 mg K, trace of
beta-carotene, 0.4-0.5 mg thiamine, 0.03 mg riboflavin, 0.8 mg niacin, and 6-7
mg ascorbic acid (Food Composition Tables). Coconut oil is one of the least
variable among vegetable fats, i.e. 0.2-0.5% caproic-, 5.4-9.5 caprylic-,
4.5-9.7 capric-, 44.1-51.3 lauric-, 13.1-18.5 myristic, 7.5-10.5 palmitic-,
1.0-3.2 stearic-, 0-1.5 arachidic-, 5.0-8.2 oleic-, and 1.0-2.6 linoleic-acids
(C.S.I.R., 1948-1976). Following oil extraction from copra, the coconut cake
(poonac) contains 10.0-13.3% moisture, 6.0-26.7% oil, 14.3-19.8% protein,
32.8-45.3% carbohydrates, 8.9-12.2% fibers, and 4.0-5.7% ash. The so-called
coconut water is 95.5% water, 0.1% protein, <0.1% fat, 0.4% ash, 4.0%
carbohydrate. Per 100 g water, there is 105 mg Na, 312 K, 29 Ca, 30 Mg, 0.1
Fe, 0.04 Cu, 37 P, 24 S, and 183 mg choline. Leaves contain 8.45% moisture,
4.282 ash, 0.56% K2O, 0.25 P2O5, 0.28 CaO, and 0.57% MgO.
Palm to 27 m or more tall, bearing crown of large pinnate leaves; trunk stout,
30-45 cm in diameter, straight or slightly curved, rising from a swollen base
surrounded by mass of roots; rarely branched, marked with rings of leaf scars;
leaves 2-6 m long, pinnatisect, leaflets 0.6-1 m long, narrow, tapering;
inflorescence in axil of each leaf as spathe enclosing a spadix 1.3-2 m long,
stout, straw or orange colored, simply branched; female flowers numerous,
small, sweet-scented, horne towards top of panicle; fruit ovoid, 3-angled,
15-30 cm long, containing single seed; exocarp a thick fibrous, husk, enclosing
a hard, bony endocarp or shell. Adhering inside wall of endocarp is testa with
thick albuminous endosperm, the coconut meat; embryo below one of the three
pores at end of fruit, cavity of endosperm filled in unripe fruit with watery
fluid, the coconut water, and only partially filled.when ripe. Fl. and fr.
year round in tropics.
Reported from the Indochina-Indonesia and Hindustani centers of origin, coconut
has been reported to tolerate high pH, heat, insects, laterites, low pH, poor
soil, salt, sand, and slope. Many classifications have been proposed for
coconuts, none is wholly satisfactory. Variations are based on height, tall
(27 m or so) or dwarf (2 m); color of plant or fruit; size of nut (some palms
have very large fruits, others have large numbers of small fruits); shape of
nuts, varying from globular to spindel-shaped or with definite triangular
sections; thickness of husk or shell; type of inflorescence; and time required
to reach maturity. Many botanical varieties and forms have been recognized and
named, using some of the characteristics mentioned above. Cultivars have been
developed from various areas. Dwarf palms occurring in India are introductions
from Malaysia, live about 30-35 years, thrive in rich soils and wet regions,
flower and fruit much earlier than tall varieties, and come into bearing by
fourth year after planting. However, dwarf varieties are not grown
commercially, and only on a limited scale because of their earliness and tender
nuts, which yield a fair quantity of coconut water. They are highly
susceptible to diseases and are adversely affected by even short periods of
drought. Tall coconuts are commonly grown for commercial purposes, 40-90
years, are hardy, and thrive under a variety of soil, climatic, and cultural
conditions, begin to flower when about 8-10 years after planting. 2n =
Now pantropical, especially along tropical shorelines, where floating coconuts
may volunteer, the coconut's origin is shrowded in mysteries, vigorously
debated. According to Purseglove (1968-1972), the center of origin of cocoid
palms most closely related to coconut is in northwestern South America. At the
time of the discovery of the New World, coconuts (as we know them today) were
confined to limited areas on the Pacific coast of Central America, and absent
from the Atlantic shores of the Americas and Africa. Coconuts drifted as far
north as Norway are still capable of germination. The wide distribution of
coconut has no doubt been aided by man and marine currents as well.
Ranging from Subtropical Dry to Wet through Tropical Very Dry to Wet
Forest Life Zones, coconut has been reported from stations with an annual
precipitation of 7-42 dm (mean of 35 cases = 20.5), annual temperature of
21-30°C (mean of 35 cases = 25.7°C) with 4-12 consecutive frost free
months, each with at least 60 mm rainfall, and pH of 4.3-8.0 (mean of 27 cases
Propagated by seedlings raised from fully mature fruits. Seeds
selected from high-yielding stock with desirable traits. Yield of copra is
final criterion, based on size and number of nuts per palm. Seednut trees
should have straight trunk and even growth, with closely spaced leaf-scars,
short fronds, well oriented on the crown, short bunch stalks, and from palms
growing under normal rather favorable conditions. Also the inflorescence
should bear about 100 female flowers, and the crown should have a large number
of fronds and consequently of inflorescences. Seednuts should be medium-sized
and nearly spherical in shape; long nuts usually have too much husk in relation
to kernel. Because male parent is unknown and because female parent is itself
heterozygous, seednuts from high-yielding palms do not necessarily reproduce
same performance in progeny; so that character alone has limited value.
Records are kept of fruits harvested from each mother palm, such as number of
bunches, number of nuts, weight of husked nuts, estimated weight of copra
(about one-third weight of husked nuts being considered favorable). After
fully mature nuts are picked, and not allowed to fall, they are tested by
shaking to listen for water within. Under-ripe, spoiled, those with no water,
or with insect or disease damage are discarded. Nuts are planted right away in
nursery or stored in a cool, dry, well-ventilated shed until they can be
planted. Seeds planted in nursery facilitate selection of best to put in
field, as only half will produce a high-yielding palm for copra. Also,
watering and insect control is much easier to manage in nursery. Soil should
be sandy or light loamy, free from waterlogging, but close to source of water,
and away from heavy shade. Nursery beds should be raised about 22 cm, and
long, separated by shallow drains to carry away excessive water. In
preparation of nursery beds, they should be dug and loosened to a depth of 30
cm. Loosened soil mixed with dried or rotten leaves and ash from burnt fresh
coconut husks at a rate of 25 lbs. of husk-ash per 225 sq. ft. Nuts spaced in
beds 22 x 30 cm, a hectare of nursery accomodating 100,000 seednuts. Nuts
planted horizontally produce better seedlings than those planted vertically.
The germinating eye is placed uppermost in a shallow furrow, about 15 cm deep,
and soil mounded up around, but not completely covering them, leaving the eye
exposed. Soaking nuts in water for 1-2 weeks before planting may benefit
germination; longer periods of soaking are progressively disadvantageous.
Bright sunlight is best for growing stout sturdy seedlings. Regular watering
in nursery is essential in dry weather, amount and frequency depending on local
conditions. Mulching sometimes used to preserve moisture and supress weeds.
Paddy straw, woven coconut leaves, and just coconut leaves are used; howevers
they might encourage termites. Potash fertilizer helps seedling growth, and
probably do not need other fertilizers as nut provides most of needed
nutrition. About 16 weeks after nut is planted, the shoot appears through the
husk, and at about 30 weeks, when 3 seed-leaves have developed, seedlings
should be planted out in permanent sites. Rigorous culling of seedlings is
essential. All late germinators and very slow growers are discarded. Robust
plants, showing normal rapid growth, straight stems, broad comparatively short
dark-green leaves with prominent veins, spreading outward and not straight
upward, and those free of disease symptoms, are selected for planting out.
Best spacing depends upon soil and terrain. Usually 9-10 m on the square is
used, planting 70-150 trees/ha; with triangular spacing of 10 m, 115 palms/ha;
and for group or bouquet planting, 3-6 palms planted 4-5 m apart. Planting
holes of 1 m wide and deep should be dug 1-3 months before seedlings are
transplanted. In India and Sri Lanka, 300-400 husks are burned in each hole,
providing 4-5 kg ash per hole. This is mixed with topsoil. Two layers of
coconut husks are put into bottom of hole before filling with the topsoil mixed
ash. Muriate of potash, 1 kg per hole, is better than ash, but increases cost
of planting. The earth settles so that it will be 15-30 cm below ground level
when seedling is planted. In planting, soil should be well-packed around nut,
but should not cover collar of seedling, nor get into leaf axils. As plant
develops, trunk may be earthed up, until soil is flush with general ground
level. Usually 7-8 month old seedlings are used for transplants. In some
instances plants up to 5 years old are used, as they are more resistant to
termite damage. If older plants are used, care must be taken not to damage
roots, as they are slow to recover. Desirable to transplant in rainy season.
In areas with only one rainy season per year, it is simpler to plant nuts in
nursery in one rainy season, and transplant them a year later. Young
plantation should be fenced to protect plants from damage from cattle, goats,
or other wild animals. Entire areas may be fenced in, individual trees, or, as
in Sri Lanka and southern India, piles of coconut husks are placed around tree.
At end of first year after transplanting, vacancies should be filled with
plants of same age held in reserve in nursery. Also any slow-growers, or
disease damaged plants should be replaced. During first 3 years, seedling
should be watered during drought, an application of ca 16 liters/tree twice a
week being recommended. Keep trees clear of weeds, especially climbers.
Usually a circle 1-2 m in radius should be weeded with mattock several times a
year, the weeds left as mulch. Cover-crops, as Centrosema pubescens,
Calopogonium mucunoides, or Pueraria phaseoloides, are used and
turned under before dry season. Catch-crops as Cassava (Manihot
utilissima), and green gram (Vigna aureus) and cowpea (Vigna
unguiculata), bananas and pineapples, may be used. Sometimes bush crops,
in addition or instead of, ground covers are used as green manures, as
Tephrosia candida, Crotalaria striata, C. uraramoensis, C. anagyroides,
all fast growers. Gliricidia sepium and Erythrina lithosperma
may be grown as hedges or live fences, their loppings used as green manure.
Usually the cheapest form of fertilizer materials for a given area are used.
General fertilizer recommended, used with suitable local modifications, would
consist of 230-300 g N, 260-460 g P2O5, and 300-670 g K2O per palm.
Application of lime is not generally recommended. There is no evidence that
salt is beneficial as is sometimes claimed. They can withstand a degree of
salinity, about 0.6%, which is lethal to many other crops. Palms seem
to need some magnesium, but are extremely sensitive to an excess. Cultivation
depends on soil type, slope of land, and rainfall distribution; often
disk-harrowing at end of monsoon rains to control weeds is all that is
necessary (Reed, 1976).
Trees begin to yield fruit in 5-6 years on good soils, more likely 7-9 years,
and reach full bearing in 12-13 years. Fruit set to maturity is 8-10 months;
12 months from setting of female flowers. Nuts must be harvested fully ripe
for making copra or desiccated coconut. For coir they are picked about one
month short of maturity, so that husks will be green. Coconuts are usually
Picked by human climbers, or cut by knives attached to end of long bamboo
poles, this being the cheapest method. With pole, a man can pick from 250
palms in a day, by climbing, only 25. In some areas nuts are allowed to fall
naturally, and collected regularly. Nuts are husked in field, a good husker
handling 2,000 nuts/day. Then nut is split, (up to 10,000 nuts per working
day). Copra may be cured by sun-drying, or by kiln-drying, or by a combination
of both. Sun-drying requires 6-8 consecutive days of good bright sunshine to
dry meat without its spoiling. Drying reduces moisture content from 50% to
below 7%. Copra is stored in well-ventilated, dry area. Extraction of oil
from copra is one of the oldest seed-crushing industries of the world. Coconut
cake is usually retained to feed domestic livestock. When it contains much
oil, it is not fed to milk cows, but is used as fertilizer. Desiccated coconut
is just the white meat, the brown part is peeled off. It is usually grated,
but may be thread or chip. Dried in driers similar to those for tea. Good
desiccated coconut should be white in color, crisp, with a fresh nutty flavor,
and should contain less than 20% moisture and 68-72% oil, the extracted oil
containing less than 0.1% of free fatty acid, as lauric. Parings, about 12-15%
of kernels, are dried and pressed for oil yielding about 55%. Used locally for
soap-making. The resulting poonac used for feeding draught cattle. Coconut
flour is made from desiccated coconut with oil removed, and the residue dried
and ground. However, it does not keep well. Coir fiber obtained from slightly
green coconut husks by retting in slightly saline water that is changed
frequently (requires up to 10 months); then, husks are rinsed with water and
fiber separated by beating with wooden mallets. After drying, the fiber is
cleaned and graded. Greater part of coir produced in India is spun into yarn,
a cottage industry, and then used for rugs and ropes. In Sri Lanka, most coir
consists of mechanically separated mattress and bristle fiber. To produce
this, husks are soaked or retted for 1-4 weeks, and then crushed between iron
rollers before fibers are separated. Bristle fibers are 20-30 cm long;
anything shorter is sold as superior mattress fiber. In some areas, dry
milling of husks, without retting, is carried on and produces only mattress
fiber. The separated pith, called bast or dust, is used as fertilizer since
the potash is not leached out. Coconuts may be stored at temperature of
0-1.5°C with relative humidity of 75% or less for 1-2 months. In storage,
they are subject to loss in weight, drying up of nut milk and mold. They may
be held for 2 weeks at room temperature without serious loss.
For copra, an average of 6,000 nuts are required for 1 ton; 1,000 nuts yield
500 lbs. of copra, which yields 250 lbs. of oil. Average yield of copra per ha
is 3-4 tons. Under good climatic conditions, a fully productive palm produces
12-16 bunches of coconuts per year, each bunch with 8-10 nuts, or 60-100
nuts/tree. Bunches ripen in about 1 year, and should yield 25 kg or more
copra. For coir, 1,000 husks yield anout 80 per year, giving about 25 kg of
bristle fiber and 55 kg of mattress fiber. Efficient pressing will yield from
100 kg of copra, approximately 62.5 kg of coconut oil, and 35 kg coconut cake,
which contains 7-10% oil. The factor 63% is generally used for converting
copra to oil equivalent. Yields of copra as high as 5 MT/ha have been
reported, but oil yields of 900-1,350 kg/ha. Pryde and Doty (1981) put the
average oil yield at 1,050 kg/ha, Telek and Martin (1981), at 600 kg/ha. World
production of coconut oil is more than 2 million tons/year, about half of which
moves in international trade. Desiccated coconut produced in countries where
palm are grown and the products exported. Sri Lanka, Philippine Islands,
Papua, and New Guinea are the largest producers. United States and United
Kingdom each import at least 50 million pounds annually. Only about 40% of
copra produced is exported, remaining 60% processed into oil in country of
origin. United States annually imports 190 million pounds of coconut oil and
more than 650 million pounds of copra; some sources state 300,000 tons copra
and over 200,000 tons coconut oil annually. Coconut oil ranks third, after
soybean and peanut oil, in world production of oils. I predict palm oil
(Elaeis) will soon move up.
The coconut of commerce weighs 0.5-1.0 kg. According to Purseglove, the
average number of nuts per hectare varies from 2,500 to 7,500 indicating yield
of ca 1,200 to 7,500 kg/ha. On the one hand, 'Jamaica Talls' fruits average
1.7 kg, nuts 0.7 kg, of which 50% is endosper; on the other, 'Malayan Dwarfs'
fruits average 1.1 kg, the nut 0.6 kg, yielding 0.2 kg copra (6,000 nuts/ton
copra). Average production yields of copra (3-8 nuts per kg copra) range from
200 kg/ha in Polynesia to 1,200 kg/ha in the Philippines, suggesting coconut
yields of 1,000 to 8,000 kg/ha. Since about 60% of this constitutes the
inedible fruit husk and seed husks, I estimate the chaff factor at 0.6.
Coconut oil, cracked at high temperatures will yield nearly 50% motor fuel and
diesel fuel. Coconut destructive distillation is reported to yield 11.5%
charcoal, 11% fuel gas, 37.5% copra spirit, 12.5% olein distillate, 1% crude
acetate, 0.15% glycerol, and 0.85% acetone plus methanol. As of June 15, 1981,
coconut oil was $0.275/lb., compared to $0.38 for peanut oil, $1.39 for
poppyseed oil, $0.65 for tung oil, $0.33 for linseed oil, $0.265 for cottonseed
oil, $0.232 for corn oil, and $0.21 for soybean oil (Chemical Marketing
Reporter, June 15, 1981). At $2.00 per gallon, gasoline is roughly $0.25/lb.
Quick (1981) tested linseed oil (Iodine number 180) which cokes up fuel
injectors in less than 20 hours and rapeseed oil (Iodine number ca 100) which
logs into the hundreds of hours before the onset of severe injector coking.
Coconut oil (Iodine number 10) should be a very good candidate from this
viewpoint. This could be very important in developing tropical countries where
diesel fuel is scarce and often more expensive than coconut oil. One
Australian patent suggests that distillation of coconuts at 550° gave 11.5%
charcoal, 11% fuel gas, and 37.5% copra spirit, 12.5% olein distillate, 12.5%
black oil, 1% crude acetic acid, 0.15% glycerol, and 0.85% (acetone + methanol)
which natural fermentation takes to 2.7-5.8% ethanol. Of course, you can't
have your coconut toddy and eat or drink or burn it too (Duke, 1977b).
Coconuts are subject to numerous fungal diseases, bacterial infections, and the
most serious virus-like disease, cadang-cadang. Coconut trees are also
attacked by numerous nematodes and some insect pests, the most damaging insect
being the black beetle or rhinoceros beetle (Oryctes rhinoceros), which
damages buds, thus reducing nut yield, and breeds in decaying refuse. Diseases
and pests of a particular area should be considered and local agent consulted
as to how to deal with them. Agriculture Handbook No. 165 (1960) lists the
following as affecting this species: Aphelenchoides cocophilus (red ring
disease), Cephalosporium lecanii, Diplodia epicocos, Endocalyx
melanoxthanus, Endoconidiophora paradoxa (leaf-bitten disease, leaf scorch,
stem-bleeding), Gloeosporium sp., Pellicularia koleroga (thread
blight), Pestalotia palmarum (gray leaf spot, leaf-break), Phomopsis
cocoes (on nuts), Phyllosticta sp. (on leaves), Physalospora
fusca (on leaves), P. rhodina (on roots and trunk), Phytopthora
palmivora (bud rot, leaf drop, wilt), Pythium sp. (wilt).
Analysing 62 kinds of biomass for heating value, Jenkins and Ebeling (1985)
reported a spread of 20.05 to 19.02 MJ/kg, compared to 13.76 for weathered rice
straw to 23.28 MJ/kg for prune pits. On a % DM basis, the fiber dust contained
66.58 % volatiles, 3.72 % ash, 29.70 % fixed carbon, 50.29 % C, 5.05 % H,
39.63 % O, 0.45 % N, 0.16 % S, 0.28 % Cl, and undertimed residue.
Complete list of references for Duke, Handbook of Energy Crops
Agriculture Handbook 165. 1960. Index of plant diseases in the United States.
Duke, J.A. 1972. Isthmian ethnobotanical dictionary. Publ. by the author.
Harrod & Co., Baltimore.
Duke, J.A. and Wain, K.K. 1981. Medicinal plants of the world. Computer index
with more than 85,000 entries. 3 vols.
Hartwell, J.L. 1967-1971. Plants used against cancer. A survey. Lloydia 30-34.
Jenkins, B.M. and Ebeling, J.M. 1985. Thermochemical properties of biomass
fuels. Calif. Agric. 39(5/6):14-16.
Pryde, E.H. and Doty, H.O., Jr. 1981. World fats and oils situation. p. 3-14.
In: Pryde, E.H., Princen, L.H., and Mukherjee, K.D. (eds.), New sources of fats
and oils. AOCS Monograph 9. American Oil Chemists' Society. Champaign, IL.
Purseglove, J.W. 1968-1972. Tropical crops. 4 vols. Longman Group Ltd.,
Purseglove, J.W. 1972. Tropical crops. Monocotyledons 2. John Wiley & Sons,
Quick, G.R. 1981. A summary of some current research in Australia on vegetable
oils as candidate fuels for diesel engines. (Abstr.) Seminar II, USDA, Peoria,
Reed, C.F. 1976. Information summaries on 1000 economic plants. Typescripts
submitted to the USDA.
Telek, L. and Martin, F.W. 1981. Okra seed: a potential source for oil and
protein in the humid lowland tropics. p. 37-53. In: Pryde, E.H., Princen, L.H.,
and Mukherjee, K.D. (eds.), New sources of fats and oils. AOCS Monograph 9.
American Oil Chemists' Society. Champaign, IL.
last update July 8, 1996