Africa rice: Oryza glaberrima
Classification of
|
Kingdom Plantae – Plants
|
Subkingdom Tracheobionta – Vascular plants
|
Superdivision Spermatophyta – Seed plants
|
Division Magnoliophyta – Flowering plants
|
Class Liliopsida – Monocotyledons
|
Subclass Commelinidae
|
Order Cyperales
|
Family Poaceae – Grass family
|
Genus Oryza L. – rice
|
Species Oryza glaberrima Steud. – African rice
|
a-Introduction
An Africa rice grain
A kind of Africa white rice
Oryza glaberrima, commonly known as African
rice, is a domesticated rice species. African rice is believed to
have been domesticated 2,000-3,000 years ago in the inland
delta of
the Upper Niger
river, in what is now Mali Africa ,
is Oryza barthii.
Oryza barthii is a wild rice grows in sub-Saharan Africa . It grows
in deep water, seasonally flooded land, stagnant water, and slowly flowing
water or pools. It is the progenitor of cultivated Oryza glaberrima, an African
rice.
The Oryza
glaberrima species is grown in West Africa ,
and shows several negative characteristics with respect to the Asian rice
species O. sativa,
such as shattering, brittle grain and poor milling quality. More importantly,
it consistently shows lower yields than O. sativa, but African rice
often shows more tolerance to fluctuations in water depth, iron toxicity,
infertile soils, severe climatic conditions and human neglect, and exhibits
better resistance to various pests and diseases, such as nematodes, rice yellow
mottle virus and the parasitic plants Striga.
The African
species of rice (O. glaberrima) was
cultivated long before Europeans arrived in the continent.
At the present time, O. glaberrima is
being replaced everywhere in West Africa by
the Asian species, introduced into the continent by the Portuguese as early as
the middle of the 16th century.
Some West
African farmers, including the Jola of southern Senegal
Recent agronomic advances now allow for gene transfer
between the two species, thus creating hybrids that are better adapted, and
higher yielding under adverse conditions, than either parent species.
There are only
two species of cultivated rice in the world: Oryza
glaberrima, or African rice, and Oryza
sativa, or Asian rice. The two species of rice have recently been
crossed, producing a promising hybrid.
Scientist from the Africa
Rice Center
managed to cross-breed African rice with Asian rice varieties to produce a
interspecific cultivar called NERICA, which is
an acronym for
"New Rice for Africa ".
b-History
Ancient History of the O. glaberrima Species
The rice of Africa (O. glaberrima) has a long and noteworthy history.
Native to
sub-Saharan Africa, O. glaberrima is thought to have been domesticated
from the wild ancestor Oryza barthii (formerly
known as Oryza brevilugata) by peoples living in the
floodplains at the bend of the Niger River
some 2,000–3,000 years ago.
The two
strains of O. sativa (O.
japonica and O.indica) were domesticated independently, both probably in China China
O. glaberrima was first domesticated in the Inland
Delta of the Upper Niger River, in what is today Mali Gambia , Casamance, and
Guinea Bissau, the other in the Guinea
forest between Sierra Leone
and the western Ivory Coast
O. glaberrima was selected for at several different
localities within the vast forest and savanna areas, where the wild ancestor
species O. barthii grew and was harvested by ancient
hunting–gathering human populations.
Whether one or
several centers of African rice domestication existed, the fact remains that
African rice was first cultivated many centuries before the first Europeans
arrived on the West African coast.
The early
Colonial history of O. glaberrima begins when the first Portuguese
reached the West African coast and witnessed the cultivation of rice in the
floodplains and marshes of the Upper
Guinea Coast
To summarize, the Jola and their neighbors were certainly
growing wet rice and using intensive techniques, such as diking to retain
rainwater and transplanting, at the time they first encountered the Europeans.
Differences Between O. glaberrima and O. sativa
Slight
morphological differences separate the two species of rice.
Generally
speaking, African rice has small grains that are pear-shaped and have a red
bran and an olive-to-black seedcoat, straight panicles that are simply
branched, and short, rounded ligules. However, some Asian rice types also have
pear-shaped grains with a red bran, and some African types have pointed
ligules.
Other ecological
characteristics of the two species may more important from the point of view of
human selection potential. African O.
glaberrima varieties have certain negative features with
respect to the Asian O. sativa:
the seed scatters easily, the grain is brittle and difficult to mill, and, most
importantly, the yields are lower.
But the O. glaberrima types also offer distinct advantages:
the plants have luxurious wide leaves that shade out weeds and the species is
more resistant than its Asian cousin to diseases and pests.
Moreover,
African rice is better at tolerating fluctuations in water depth, iron
toxicity, infertile soils, severe climates, and human neglect. Some O. glaberrima types also mature faster than Asian
types, making them important as emergency food. These characteristics have made
it worthwhile to attempt to cross both species, a feat that that has recently
met with considerable success.
Tragically,
food production in sub-Saharan Africa is
diminishing by 1% a year. Per capita food production in 1966–1968 averaged 119
kg per person per year. By 1982–1984, it had fallen to 98 kg per person per
year, and by 1993 to 91 kg per person per year In 1999 it climbed slightly to
94 kg per person per year. As early as the end of the 1960s, population growth
was outstripping the annual growth of agricultural production. Thus from 1965
to 1973, population grew by 2.7%, whereas agriculture grew by 2.4%; this
relationship was 2.9% to 1.1% from 1973 to 1980, and 3.0% to 2.1% from 1980 to
1990 “Africa is moving rapidly toward a third
decade of declining food production and increasing population growth”.
In the 1960s,
many African farmers were producing enough rice to feed themselves. Since then,
yearly imports have increased 8-fold to 4 million metric tons .
The situation
in Senegal Senegal
was importing rice from Southeast Asia, and later Mali Lower
Casamance were largely self-sufficient. Rice imports for Senegal
In the 1992–1993 marketing year, the cereal
import requirements for rice was 400,000 tons, or ≈57% of all cereal imports.
This amount increased to >557,000 in 1998. The broken rice that is imported
is sold to wholesalers in Dakar
The Distribution of O. glaberrima.
In West Africa, rice is grown as the main staple crop by
10–15 million people living in societies that are distributed along the coast,
from the Casamance in Senegal
to the bend of the Bandama River in the Ivory Coast Lake Chad . Rice is also grown
today as a commercial crop in Ghana
and Nigeria
In the coastal area, where rice is a dominant subsistence
crop, isolated pockets of O. glaberrima cultivation
remain in Guinea Bissau, Guinea, Sierra Leone ,
and in the Casamance region of southern Senegal
Everywhere, however, O. glaberrima types
are fast being replaced by the higher yielding O. sativa varieties. This phenomenon is
documented below with respect to the Jola peoples of Casamance, who some
decades ago planted numerous varieties of African rice but no longer do so. The
discussion that follows documents the O. glaberrima types
that Jola cultivated in the 1960s, the reasons why they were abandoned, and the
cultural context in which they still survive.
Important
regional differences exist in the gender division of labor, the dominance of
upland versus floodplain cultivation, the ratio of transplanted to
direct-seeded rice, and the role played by secondary and commercial crops. But
everywhere in the Jola area, rice is the dominant subsistence crop. It is grown
all over the countryside, in tidal zones recovered from the mangrove
vegetation, inland freshwater valleys, and low plateaus. It is also cultivated
in peri-urban zones around secondary cities such as Ziguinchor, the capital of
the Casamance, and Bignona, a town north of the Casamance River
The rice
samples collected were then identified in 1966 by R. Portères, the renowned
rice expert, who divided the sample into the two species and named their
various subspecies and types.
In summary, 6
of 19 varieties, or nearly one-third of the rice that was grown in 1965 by the
inhabitants of the Jipalom community, belonged to the African rice (O. glaberrima) species. Interviews with the elderly
ladies of the community confirmed that in the not-too distant past they grew
many more African rice varieties.
Without the slightest
hesitation they could name at least ten O.
glaberrima varieties that were no longer planted. It is also
quite probable that further south, in the more intensive rice-growing zone
south of the Casamance
River
To this day,
African rice varieties are known in Jipalom under the general terms “ajola”
(from the Jola, their ethnic label), or “ecasay” (from Casamance), whereas
types of the introduced Asian species are known as “amanding” rices, to
indicate that they were brought in by the Manding peoples, a nation of traders
with which the Jola have had protracted interactions through the centuries.
In Jipalom, it
is the women who select the rice seed; it is they, and not the men, who can
distinguish the different varieties
The cultural aspects that dominate Jola women's choice of
which varieties to plant have to do with their taste, the ease with which they
are pounded (or milled), and how they respond to cooking.
A Jola can usually tell the general region from which a
particular variety comes, and how long it has been stored, by its taste. Rice
varieties from the southern Jola area tend to be “sweeter” tasting, except when
they have been stored for a long time in granaries placed on the ceiling of the
cooking huts; rice thus stored acquires a smoky taste. Jola women also prefer
longer-grained rice, which is easier to pound, and nonglutinous varieties that
they say are easier to cook.
Curiously, they also reject the long-grained rice that United States
Old Varieties Disappear and New Ones Are Introduced
In the late
1960s, and for several ensuing decades, many sub-Saharan African countries,
including Senegal Senegal Lower Casamance to the south. In Bignona, a town close to
the Jipalom community, rainfall for the month of June 1968 was only one-third
that of previous years.
August and
September, crucial months when the rain-fed fields had to be tilled before
transplanting, received <200 mm of rain each, compared with >500 mm the
year before.
In fact, the mean precipitation for Bignona in the years
1968–1977 was insufficient, with 1,056.33 mm of rain, compared with 1,436.41 mm
for the years 1958–1967. But drought years were not always in consecutive
years. Whereas 1969 and 1970 had a satisfactory precipitation, 1971 and
especially 1972 were deficit years. Rain gauges set up in the community of
Sindian, very near to Jipalom, registered <1,000 mm in 14 of 20 years
between 1973 and 1993. In 1980, the situation had been catastrophic, with 676
mm of rainfall falling in the entire year. Insofar as rice cultivation was
concerned, the situation certainly qualified as an agricultural drought, when
plants suffered seriously from lack of moisture.
Conditions
improved somewhat in the years after 1993. For example, precipitation in the
Sindian area was 1,310 mm in 1994 and 1,435 mm in 1999. But the mean
precipitation all over the Lower Casamance
during the last decades has been several hundred millimeters below what it had
been in the decades preceding the late 1960s.
One of the
marked changes brought about by the rainfall deficit was the loss of many of
the old rice varieties as new, fast-growing types were introduced by extension
agents from national research centers such as DERBAC (Projet de Developpement
Rural de la Casamance), and foreign development schemes such as the
Dutch-financed ILACO (International Land Development Consultants) project.
Thus, in 1989,
only 13 varieties of rice were being grown in Jipalom, compared with 19 in
1965–1966. Of the 1989 varieties, three were old O. sativa varieties that had been around before, and
the rest were new, fast-ripening O.
sativa varieties
that had been introduced in the preceding years. The inhabitants could name at
least seven of the old O. sativa varieties
that had been abandoned.
Interestingly,
only 2% or 15% of the varieties grown belonged to the African O. glaberrima species. Therefore, there had been a
notable loss of diversity in the rice varieties being grown twenty years after
the drought began.
The loss of
diversity was very marked in the agricultural year 1999–2000. In that year,
only nine varieties of O. sativa were
being grown in the village, and only one variety of the O. glaberrima species.
Although some
African types mature rapidly, their relatively low yields and difficulty in
pounding or milling discouraged farmers from growing them.
African O. glaberrima Varieties Survive in Ritual Context
In communities
north of the Casamance
River
Here, traditions relate that the supreme
deity, the rain “god” known as Emitai, gave “Diola rice” (O. glaberrima) to the ancestors. This rice carried a
life-giving power that explained the ultimate origins of the land that Emitai
had bestowed upon the inhabitants. For this reason, some varieties of O. glaberrima should always be planted, to preserve
the link to the ancestors, and to Emitai, who sends rain.
This marshy terrain is crisscrossed by marigotsthat create
small islands where the people live and cultivate their rice fields. Because
many of the fields are bathed by brackish water, the inhabitants like to grow
the glaberrima species, which is tolerant of
salt-saturated soils. The main function of the ejonkin rice is ritual, to propitiate the
rain-shrine called Husurah.
This important
shrine must be propitiated with African rice; varieties of the Asian species
cannot be used. Small quantities of cooked rice belonging to any O. glaberrima species, in this instance ejonkin, must be placed each year around the shrine to
ask for abundant rains. The participants in the ritual, however, often eat
cooked rice belonging to O.
sativa varieties.
Thus, what is eaten is kept separate from what is required in sacred rituals.
Moreover, it
is said that O. glaberrima varieties are difficult to thresh using
one's feet because grains are arranged in a row on the spine. And they are
difficult to pound (i.e., mill) because the red bran cannot be easily removed,
and are slow to cook.
It is
doubtful, however, that in former days, those who grew and cooked rice found it
necessary to remove the bran, or to boil the rice for a short period.
In any case,
African rice is said be “heavier” on the stomach and hence better at quenching
hunger. It also makes a good flour that is more aromatic and tastes better than
the flour made from theO. sativa species.
As a flour it can be consumed as a drink, as porridge, cooked as dumplings, or
grilled over hot cinders.
To summarize, the ancient species of African rice survives
in pockets of Lower Casamance , where the Jola
employ it in sacred rites. This is a common occurrence. All over the world, old
“traditional” cultivars are used in ceremonies to propitiate the spirits, for
the link between crops and the ancestors is a fundamental pillar of most
agrarian societies. The Mende peoples of Sierra Leone
c- NERICA: The new rice for Africa
The new
varieties, named “New Rice for Africa ” (hence
NERICA), are a cross between O.
glaberrima and O.
sativa. They
combine the hardiness of the African species with the productivity of the Asian
species. Scientists at the West African Rice Development Association (WARDA)
succeeded in crossing the two species by employing embryo rescue techniques
that ensure the crosses are fertile and mature successfully due to high levels
of hybrid vigor .
In doing so, they used seeds of African rice
varieties that local farmers, many of them women from Guinea
NERICA
varieties shade out weeds, are resistant to pests and droughts, grow in poor
soils, and mature 30–50 days earlier than traditional varieties. Moreover, they
produce 400 grains per plant (as opposed to 75–100 in the older varieties),
contain 2% more proteins and, as a bonus, are said to taste like African rice.
The high
productivity conferred on the NERICA strains by their Asian parents means that
yields can be increased from the previous 1 ton per hectare to 1.5 tons without
major inputs. With fertilizers and good care yields can double or even triple.
Thus, the new rice holds great promise for a region in desperate need of
decreasing hunger and increasing food security.
The enormous
scientific efforts that produced NERICA will result in a “Green Revolution” in
which nearly 1.7 million West African farmers will benefit from increased food
security. It will help their countries save millions of dollars in rice
imports. The basis for this success story is to be found in those West African
farmers who continued to grow the ancient O.
glaberrima varieties of rice despite the introduction of the
new Asian species. Their knowledge, expertise, and continued adherence to their
traditional rice provided the basis for experiments that resulted in the
creation of a promising new hybrid. Thus, both cultural and ecological
variables entered significantly into these developments.
Preferences:
5-Poaceae (Gramineae) - www.botany.hawaii.edu/faculty/carr/po.htm .
No comments:
Post a Comment