The New Rice for Africa (NERICA) varieties are the first wide-scale success of crossing of the two cultivated species: Oryza sativa, known as ‘Asian rice’, and O. glaberrima, often called ‘African rice’ and found only in Africa
There are two types of the NERICA varieties: upland NERICAs and lowland NERICAs (NERICA-L), adapted for either rainfed or irrigated environments. In total there are now 82 NERICA varieties – 18 upland, 60 rainfed lowland and 4 irrigated varieties. The NERICA varieties for various rice ecologies are a significant international public good.
The ability of the African rice to grow under low input conditions makes it an especially useful genetic resource for developing stress-tolerant rice varieties for rainfed ecosystems in Africa. In 1992, a team led by Dr Monty Jones, a senior rice breeder of AfricaRice, decided to work on interspecific hybridization to develop varieties that might combine the high yield potential of Asian rice with the local adaptation of African rice.
The African rice varieties show strong adaptability to harsh environments, strong ability to compete with weeds, resist local diseases and pests, and withstand drought, flood, infertile soils, and iron toxicity.
Several attempts to exploit the African rice genome through interspecific crossing had failed due to incompatibility barriers.AfricaRice circumvented the sterility barrier between the two species by using anther culture and embryo rescue techniques, coupled with back-crossings to the Asian rice parent. Several hundred interspecific progenies with promising agronomic performance were generated, increasing the biodiversity of rice.
The interspecific lines were evaluated across Africa by farmers through participatory varietal selection (PVS), which is an innovative approach that allows farmers to select their preferred varieties that match their needs and growing conditions, and that generates valuable feedback on farmers’ preference criteria for rice breeders.
The most successful lines, based on their performance and popularity among upland rice farmers, were named the NERICA varieties. The first NERICA varieties were released in Côte d’Ivoire in 2000. The development of the upland NERICA earned AfricaRice several international awards including the World Food Prize in 2004 to Monty Jones.
NERICA lines have been tested in 31 SSA countries using the PVS approach. NERICAs have been widely adopted by farmers in many parts of Africa. It is estimated that in 2013, the area under NERICA cultivation was about 1.4 million ha.
Upland NERICA varieties give yields that are generally as good as the Asian rice varieties. They are early-maturing (75-100 days) and are relatively tolerant of major stresses of Africa’s harsh growth environment. However, not all of these characteristics are found in one single NERICA variety.
Early maturity for example is much appreciated by farmers, especially women farmers, as it allows them to have food during the ‘hunger period’ while waiting for the harvest of other crops. Additionally, studies show that some NERICA varieties have on average 25 per cent higher protein than imported Asian varieties.
Currently, there are 18 NERICA varieties (NERICA-1 to NERICA-18) suited for upland cultivation. NERICA-4, which is tolerant to drought and phosphorus deficiency, is the most widely adopted upland variety, grown in more than 10 SSA countries.
Benefits and impact on livelihoods at the pilot sites
An impact study has shown that about 8 million people were lifted out of poverty and food insecurity thanks to the adoption of improved rice varieties, including NERICA.
The scalability of the NERICA varieties has already been demonstrated in Africa. The success of the varieties has now expanded beyond the African continent. The NERICAs are being used by farmers for rice production and by breeders in varietal improvement programs in Bangladesh, China, India and several other countries around the world.
Lowland NERICA (NERICA-L)
In 1998/1999, AfricaRice started to extend its NERICA program to the rainfed lowland ecosystem. The lowlands – where rice is grown in bunded fields that are flooded for at least part of the growing season – are generally more fertile than the uplands.
But the rainfed lowlands are very complex rice ecologies. Lack of water control, iron toxicity, weeds, and highly destructive diseases and pests are the major challenges to rice production. Yields of traditional rice varieties for this ecology are low, usually less than 1.5 tonnes per ha or around 40% of the world average.
Development of the rainfed lowland NERICAs was led by AfricaRice scientist Dr Moussa Sié. The breeding program was initiated from crossing specific African rice varieties, known for their resistance to rainfed lowland stresses, with popular—but susceptible—Asian rice varieties.
The rainfed lowland NERICA development was facilitated through the shuttle-breeding approach with national programs in West and Central Africa to accelerate the selection process and achieve wide adaptability of the rainfed lowland NERICAs.
Sixty rainfed lowland NERICA varieties (NERICA-L), with yield potential of 6 to 7 tons per hectare and good resistance to major lowland stresses, were selected by farmers in several African countries through the PVS process.
The first lowland NERICAs were released in 2005. The most popular rainfed lowland variety NERICA-L 19 yields 5–7 t/ha, and is tolerant to iron toxicity, drought and blast. The work on rainfed lowland NERICAs earned Dr Sié the Fukui International Koshihikari Rice Prize from Japan in 2006.