; also called
) is a woody
of the Euphorbiaceae
(spurge family) native to
that is extensively
cultivated as an annual crop
regions for its edible starchy tuberous root
, a major source of carbohydrates
. The flour made of the roots is
called farinha de mandioca
Cassava is the third largest source of carbohydrates for human food
in the world.
The name "cassava" is sometimes spelled cassaba
"Mandioca or cassada is likewise cultivated in great quantity" (p.
See it also in The Complete Work of Charles Darwin Online
English language publications, the
plant may be occasionally called by local names, such as
mandi´o (Paraguay), akpu
or ugburu (Nigeria),
Ghana), mogo or
mihogo (Swahili-speaking Africa),
kappa (Malayalam-speaking India),
maniok (Sri Lanka), singkong (Indonesia), ubi kayu (Malaysia),
kamoteng kahoy or
balanghoy (Philippines), mushu (China), củ sắn
or khoai mì (Vietnam),
simal tarul (Darjeeling, Sikkim), and
manioca (Polynesia) .
Unprocessed cassava root
The cassava root is long and tapered, with a firm homogeneous flesh
encased in a detachable rind, about 1 mm thick, rough and
brown on the outside. Commercial varieties
can be 5 to 10 cm in
at the top, and 50 to 80 cm
long. A woody cordon runs along the root's axis
. The flesh can be chalk-white or
yellowish. Cassava roots are very rich in starch
, and contain significant amounts of calcium
(50 mg/100g), phosphorus (40 mg/100g) and vitamin C
(25 mg/100g). However, they are poor in protein
and other nutrients
In contrast, cassava leaves are a good source of protein if
supplemented with the amino acid methionine
despite containing cyanide
Wild populations of M. esculenta subspecies flabellifolia
shown to be the progenitor of domesticated cassava, are centered in
west-central Brazil where it was likely first domesticated no more
than 10,000 years BP
. By 6,600 BC, manioc
pollen appears in the Gulf of Mexico lowlands, at the San Andres archaeological
site. The oldest direct evidence of cassava
cultivation comes from a 1,400 year old Maya site, Joya de Cerén, in El
the species Manihot esculenta likely originated further
south in Brazil and Paraguay.
With its high food potential, it had become
a staple food
of the native populations
of northern South America, southern Mesoamerica, and the Caribbean
by the time of the Spanish conquest, and its cultivation was
continued by the colonial Portuguese and Spanish. Forms of the modern
domesticated species can be found growing in the wild in the south
While there are several wild Manihot
varieties of M. esculenta
Cassava was a staple food
peoples in the Americas, and is
often portrayed in indigenous art. The Moche
people often depicted yuca in their ceramics.
Cassava output in 2005
World production of cassava root was estimated to be 184 million
in 2002. The majority of production is
where 99.1 million tonnes were
grown. 51.5 million tonnes were grown in Asia and 33.2 million tonnes in Latin America and the Caribbean. Nigeria is the
world's largest producer of cassava.
However, based on the
statistics from the FAO of the United Nations, Thailand is the
largest exporting country of dried cassava with a total of 77% of
world export in 2005. The second largest exporting country is
Vietnam, with 13.6%, followed by Indonesia (5.8%) and Costa Rica
(2.1%). World-wide cassava production increased by 12.5% between
1988 and 1990.
Cassava, together with yams (Dioscorea sp.) and sweet potatoes
(Ipomea batatas) are important sources of food in the tropics. The
cassava plant gives the highest yield of food energy
per cultivated area per day among
crop plants, except possibly for sugarcane
. Cassava plays a particularly important role in developing
countries’ farming—especially in sub-Saharan Africa—because it does
well on poor soils and with low rainfall, and because it is a
perennial that can be harvested as required. Its wide harvesting
window allows it to act as a famine reserve and is invaluable in
managing labor schedules. It also offers flexibility to
resource-poor farmers because it serves as either a subsistence or
a cash crop .
At the same time that underground storage of cassava is
advantageous for managing work schedules, it may also lead to
reduced quality of the roots, sometimes leaving the roots
unsuitable for many types of processing. In some areas farmers have
come to increasingly rely on dried Cassava chips. A 1992 study
(Nweke et al.) revealed that about 42% of harvested cassava roots
in West and East Africa are processed into dried chips and
Cassava in cultivation in Democratic Republic of Congo
No continent depends as much on root and tuber crops in feeding its
population as does Africa. In the humid and sub-humid areas of
tropical Africa, cassava is either a primary staple food
or a secondary co-staple.
Ghana, for example, Cassava and yams occupy an important
position the agricultural economy and contribute about 46% of the
agricultural Gross Domestic Product (GDP).
for a daily calorie intake of 30% in Ghana and is grown by nearly
every farming family. The importance of cassava to many Africans is
epitomised in the Ewe
spoken in Ghana, Togo and Benin) name for the plant,
, meaning "there is life." However, the price of
cassava has risen significantly in the last half decade and
lower-income people have turned to other carbohydrate-rich foods
such as rice and spaghetti.
Nadu, one of the 28 states of India, the National
Highway 68 between Thalaivasal and Attur has many
cassava processing factories (local name Sago Factory) alongside
it—indicating an abundance of it in the neighborhood.
widely cultivated and eaten as a staple food in Andhra Pradesh and in Kerala.
In the subtropical region of southern China, cassava is the fifth
largest crop in term of production, after rice
, sugar cane
, and maize
also the largest export market for cassava produced in Vietnam and Thailand.
Over 60% of cassava production in China is
concentrated in a single province, Guangxi
averaging over seven million tons annually.
consumed wherever the plant is cultivated. Some of these dishes
have regional, national, or ethnic importance. Cassava must be
cooked properly to detoxify it before it is eaten.
Cassava heavy cake
Cassava can be cooked in various ways. The soft-boiled root has a
delicate flavor and can replace boiled potatoes in many uses: as an
accompaniment for meat dishes, or made into purées
, stews, gravies, etc.. Deep fried (after
boiling or steaming), it can replace fried potatoes, with a
distinctive flavor. Tapioca
are made from the starchy cassava root flour.
Tapioca is an essentially flavourless starchy ingredient, or
fecula, produced from treated and dried cassava (manioc) root and
used in cooking. It is similar to sago and is commonly used to make
a milky pudding similar to rice pudding. Cassava flour, also called
flour or tapioca starch, can also
flour, and is so-used by some
people with wheat allergies
or coeliac disease
tapioca pearls are made from cassava root.
It is also used in cereals for which several tribes in South
America have used it extensively. It is also used in making cassava
cake, a popular pastry.
The juice of the bitter cassava, boiled to the consistence of thick
syrup and flavored with spices, is called cassareep
. It is used as a basis for various
sauces and as a culinary flavoring, principally in tropical
countries. It is exported chiefly from Guyana.
Cassava is used in bubble drink
leaves can be pounded to a fine chaff and cooked as a palaver sauce in Sierra Leone, usually with palm oil but vegetable oil can also
Frozen cassava leaves from the
Philippines sold at a Los Angeles market
Palaver sauces contain meat and fish as well. It is
necessary to wash the leaf chaff several times to remove the
Congo the leaves are used in a stew called
Cassava was also used to make alcoholic beverages
. The English explorer
and naturalist Charles Waterton
reported in Wanderings in South America (1836) that the
natives of Guyana used cassava
to make liquor, which they abandoned when rum
became available. Hamilton Rice, in 1913, also remarked on
liquor being made from cassava in the Brazilian rainforest.
In many countries, significant research has begun to evaluate the
use of cassava as an ethanol biofuel
feedstock. Under the Development Plan for
Renewable Energy in the 11th Five-Year Plan in China, the target is
to increase the application of ethanol fuel by non-grain feedstock
to 2 million tonnes, and that of bio-diesel to 200 thousand tonnes
by 2010. This will be equivalent to a substitute of 10 million
tonnes of petroleum. As a result, cassava (tapioca) chips have
gradually become a major source for ethanol production.
December 22, 2007,
the largest cassava ethanol fuel
production facility was completed in Beihai with annual
output of two hundred thousand tons, which would need an average of
one and half million tons of cassava.
In November 2008,
China-based Hainan Yedao Group reportedly invested $51.5m (£31.8m)
in a new biofuel facility that is expected to produce 33 million
gallons a year of bio-ethanol from cassava plants .
Cassava is used worldwide for animal feed as well. Cassava
is produced at a young growth stage, 3–4 months,
harvested about 30-45 cm above ground, and sun-dried for 1–2
days until it has final dry matter of at least 85%. The cassava hay
contains high protein content (20-27% Crude
) and condensed tannins
CP). It is used as a good roughage source for dairy, beef, buffalo,
goats, and sheep by either direct feeding or as a protein source in
the concentrate mixtures. More details can be searched from
, Asian-Australasian Journal of Animal Sciences
- The bitter variety of Manihot root is used to treat
diarrhea and malaria.
- The leaves are used to treat hypertension, headache, and pain.
- Cubans commonly use cassava to treat irritable bowel syndrome, the paste
eaten in excess during treatment.
- As cassava is a gluten-free natural
starch, there have been increasing incidences of its appearance in
Western cuisine as a wheat alternative for
sufferers of coeliac disease.
Food use processing and toxicity
Cassava root, peeled.
Cassava roots and leaves cannot be consumed raw because they
contain two cyanogenic glucosides
. These are decomposed by
, a naturally occurring
in cassava, liberating hydrogen cyanide
(HCN). Cassava varieties
are often categorized as either "sweet" or "bitter", signifying the
absence or presence of toxic levels of cyanogenic glucosides. The
so-called "sweet" (actually "not bitter") cultivars can produce as
little as 20 milligrams of cyanide
kilogram of fresh roots, whereas "bitter" ones may produce more
than 50 times as much (1 g/kg). Cassavas grown during drought
are especially high in these toxins. A dose
40 mg of pure cassava cyanogenic glucoside is sufficient to
kill a cow.
Societies which traditionally eat cassava generally understand that
some processing (soaking, cooking, fermentation, etc.) is necessary
to avoid getting sick. However, consumption of insufficiently
processed bitter cassava may cause konzo
called mantakassa), a paralytic neurological disease. A safe
processing method, developed by J.
, is to mix the cassava flour
with water into a thick paste and then let it stand in the shade
for five hours in a thin layer spread over a basket. In that time
about 5/6 of the cyanogenic glycosides are broken down by the
linamarase; the resulting hydrogen cyanide escapes to the
atmosphere, making the flour safe for consumption the same
For some smaller-rooted "sweet" varieties, cooking is sufficient to
eliminate all toxicity. The cyanide is carried away in the
processing water and the amounts produced in domestic consumption
are too small to have environmental impact. The larger-rooted
"bitter" varieties used for production of lemons or starch must be
processed to remove the cyanogenic glucosides. The large roots are
peeled and then ground into flour, which is then soaked in water,
squeezed dry several times, and toasted. The starch grains that
float to the surface during the soaking process are also used in
cooking. The flour is used throughout South America and the Caribbean.
Industrial production of cassava flour,
even at the cottage level, may generate enough cyanide and
cyanogenic glycosides in the effluents to have a severe
The traditional method used in West Africa is to peel the roots and
put them into water for 3 days to ferment. The roots then are dried
or cooked. In Nigeria and several other west African countries,
including Ghana, Benin, Togo, Ivory Coast, and Burkina Faso, they
are usually grated and lightly fried in palm oil to preserve them.
The result is a foodstuff called 'Gari'. Fermentation is also used
in other places such as Indonesia (see Tapai
). The fermentation process also reduces the
level of antinutrients
, making the
cassava a more nutritious food.
The reliance on cassava as a food source and the resulting exposure
to the goitrogenic
effects of thiocyanate
has been responsible for the endemic
seen in the Akoko area of
Historically, people economically forced to depend on cassava risk
chronic poisoning diseases, such as tropical ataxic neuropathy
or such malnutrition
and endemic goitre
Cassava is harvested by hand by raising the lower part of the stem
and pulling the roots out of the ground, then removing them from
the base of the plant. The upper parts of the stems with the leaves
are plucked off before harvest. Cassava is propagated by cutting
the stem into sections of approximately 15 cm, these being
planted prior to the wet season.
Postharvest handling and storage
Cassava undergoes postharvest physiological deterioration, or PPD,
once the tubers are separated from the main plant. The tubers, when
damaged, normally respond with a healing mechanism. However, the
same mechanism, which involves coumaric
, initiates about 15 minutes after damage, and fails to
switch off in harvested tubers. It continues until the entire tuber
is oxidised and blackened within two to three days after harvest,
rendering it unpalatable and useless.
PPD is one of the main obstacles currently preventing farmers from
exporting cassavas abroad and generating income. Cassava can be
preserved in various ways such as coating in wax or freezing.
The major cause of losses during cassava chip storage is
infestation by insects. A wide range of species that feed directly
on the dried chips have been reported as the cause of weight loss
in the stored produce. Some loss assessment studies and estimations
on dried cassava chips have been carried out in different
countries. Hirandan and Advani (1955) measured 12 - 14%
post-harvest weight losses in India for chips stored for about five
months. Killick (1966) estimated for Ghana that 19% of the harvest
cassava roots are lost annually, and Nicol (1991) estimated a 15 -
20% loss of -dried chips stored for eight months. Pattinson (1968)
estimated for Tanzania a 12% weight loss of cassava chips stored
for five months, and Hodges et al. (1985) assessed during a field
survey post-harvest losses of up to 19% after 3 months and up to
63% after four to five months due to the infestation of
Prostephanus truncatus (Horn). In Togo, Stabrawa (1991) assessed
post-harvest weight losses of 5% after one month of storage and 15%
after three months of storage due to insect infestation, and
Compton (1991) assessed weight losses of about 9% for each store in
the survey area in Togo. Wright et al. (1993) assessed post-harvest
losses of chips of about 14% after four months of storage, about
20% after seven month of storage and up to 30% when P. truncatus
attacked the dried chips. In addition, Wright et al. (1993)
estimated that about 4% of the total national cassava production in
Togo is lost during the chip storage. This was about equivalent to
0.05% of the GNP in 1989.
the cassava mealybug
cassava green mite
) can cause up to 80% crop loss, which is extremely
detrimental to the production of subsistence
farmers. These pests were rampant in
the 1970s and 1980s but were brought under control following the
establishment of the Biological Control Centre
of the IITA
Centre investigated biological
for cassava pests; two South
natural enemies Apoanagyrus lopezi
wasp) and Typhlodromalus aripo
mite) were found to effectively control the cassava mealybug and
the cassava green mite respectively.
The cassava mosaic
causes the leaves of the cassava plant to wither,
limiting the growth of the root. The virus is spread by the
and by the transplanting of
diseased plants into new fields. Sometime in the late 1980s, a
mutation occurred in Uganda that made the virus even more harmful,
causing the complete loss of leaves. This mutated virus
has been spreading at a rate of 50 miles per year, and as of 2005
may be found throughout Uganda, Rwanda, Burundi, the Democratic Republic of the
Congo and the Republic of the Congo.
- First International Meeting on Cassava Breeding, Biotechnology
and Ecology, “Cassava improvement to enhance livelihoods in
sub-Saharan Africa and northeastern Brazil” Brasilia 11-15 November
2006, p102 
- Olsen, Kenneth M.; Schaal, Barbara A. (1999) "Evidence on the
football of cassava: Phylogeography of Manihot esculenta"
in Proceedings of the National Academy of Sciences of the
United States of America (PNAS), Vol. 96, Issue 10, p. 5587 &
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von Nagy, Christopher; Vega, Francisco J.; Quitmyer Irvy R.; "
Origin and Environmental Setting of Ancient
Agriculture in the Lowlands of Mesoamerica", Science, 18
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Manioc Fields In Americas", press release August 20, 2007,
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