NERICA: The new rice for
The traditional African rice species
Rice has a long and varied history in
African farmers probably domesticated this grain at the same time as Asian
farmers – about 3,000 years ago. African farmers developed the species Oryza glaberrima, while Asian farmers
developed Oryza sativa.
African rice Oryza glaberrima has been cultivated for 3,500 years and is well adapted to the African environment. African rice has profuse vegetative growth, which serves to smother weeds; it is also resistant to drought, the insect pest African rice gall midge, rice yellow mottle virus and blast disease. However, African rice has relatively low yields, because it lodges, or falls over, when grain heads are full. Grains may also shatter, further reducing yield.
Oryza sativa was introduced to Africa about 500 years ago, however, and peasants there have adapted it to their rice production systems, developing many local varieties of the Asian species and turning
Africa into an important secondary
source of diversity.
Cultivation of African rice has been abandoned for the cultivation of high-yield Asian varieties of Oryza sativa. Asian varieties are poorly adapted to African conditions as their cultivation requires abundant water. Asian rice cannot compete with weeds due to their semi-dwarf phenotypes and are susceptible to pests and diseases in African conditions.
Most of the 20 million rice farmers in
West Africa are bound
to an environmentally degrading slash-and-burn farming system. Asian rice
species which entered Africa 450 years ago
can't compete with the weeds, so after a crop or two it's time to clear more
land. Planting the traditional African rice species is not worthwhile for
farmers as it simply does not produce enough rice.
Although 240 million people in
West Africa rely on rice as the primary source of food
protein in their diet, the majority of this rice is imported, at a cost of USD 1
billion. Self-sufficiency in rice production would improve food security and
aid economic development in West Africa.
Finding out the new rice varieties for Africa
In 1991, a biotechnology-based programme was initiated to combine the best traits of the Asian and African rices. Vital to the effort were gene banks that contain seeds of 1500 African rices - which had faced extinction as farmers abandoned them for higher yielding Asian varieties.
The rapid advances in agricultural science enabled the development of NERICA. Scientists at the West Africa Rice Development Association (WARDA) overcame a series of disappointing failures when they succeeded in crossing two species using embryo rescue techniques.
The first Nerica variety was developed in 1994 by researchers at WARDA, using an Oryza sativa japonica variety (WAB 56-104) and an African Oryza glaberrima variety (CG 14).
New Rice for Africa ("NERICA") is an interspecific cultivar of rice developed by the
to improve the yield of African rice varieties. The results of the NERICA
Project, which is funded by the African Development Bank, the Japanese
government, and the United
Nations Development Programme, was a major agenda item at the Fourth Tokyo
International Conference on African Development (TICAD-IV)
in 2008. The new rice varieties, which are suited to drylands, were distributed
and sown on more than 200,000 hectares during the last five years in several
African countries, notably Africa Rice
Center Guinea, Nigeria, Côte
d’Ivoire, and Uganda,
according to the .
Though this represents a major advance, it is still projected to fall short of
meeting the growing demand for rice as a food staple. Africa
The new varieties, named “New Rice for
NERICA), are a cross between and 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
, grew in their fields, and
incorporated them into gene banks. The farmers, in turn, provided information
to the scientists about the traits that they most valued in the new hybrids. Guinea
The new rice smothers grain-robbing weeds like it's African parents, resists droughts and pests, and is able to thrive in poor soils. The trait of higher productivity conferred by it's Asian parents is also present, meaning that with few additional inputs the farmers using NERICA rice can double production and raise incomes. It is helping to meet multiple needs - food, nutrition and income - for millions of people in the humid tropics of
The panicles of this rice variety can hold 400 grains compared to the 75-100 grains of it's African parents. Further improvements in the plants architecture such as longer panicles with forked branches, strong stems and panicles that hold grain tightly and prevent shattering- will allow the new varieties to out yield others and produce bountiful harvests with modest fertilisation.
They mature 30-50 days earlier than traditional varieties allowing farmers to grow extra crops of vegetables or legumes. They are taller thus making harvesting easier and they grow better on the fertile, acid soils that comprise 70% of the upland rice area in the region. In addition, there is 2% more body building protein in these new varieties than either their African or Asian parents.
Key features of the new varieties include:
-An increase in grain head size from 75-100 grains per head to 400 grains per head.
-An increase in yield from 1 tonne per hectare to 2.5 tonnes per hectare, yield increases to 5 tonnes per hectare with fertilizer use.
-Contains 2% more protein than their African or Asian parents.
-They are taller than most rices, which makes harvesting easier.
-They resist pests, and they tolerate drought and infertile soils better than Asian varieties.
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.
Some NERICA lines show high growth with low uptake of water and seem to be appropriate for long periods of cultivation in drought condition.
If 25% of rice farmers in
d'Ivoire and adopt
the new varieties it is estimated that USD 20 million will be saved each year.
The rices may also be valuable to rice producers in other dry environments,
including areas of Latin America and Sierra Leone Asia.
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 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.
1-"NERICA COMPENDIUM". WARDA. 2006. Retrieved 2008.
2-"Lowland NERICA". WARDA. 2006. Retrieved 2008-07-07.
3- NERICA - new rice for West Africa-www.scienceinafrica.co.za/nerica.htm
4-GRAIN — Nerica: a 'wonder' rice? www.grain.org/article/entries/752-nerica-a-wonder-rice.
5-Farmers embrace African 'miracle' rice-www.un.org/en/africarenewal/vol17no4/174rice.htm.