Breakthrough

WARDA’s innovative partnership model, especially with the national programs of West Africa through the Rice Research and Development Network for West and Central Africa (ROCARIZ), has recently led to another breakthrough: the development of a new generation of NERICA varieties adapted to lowland rice ecologies.

The potential of lowland is much higher than that of upland ecologies, as they are suited to cropping intensification, with the possibility of growing two or more crops per year. Rice thus becomes economically a more valuable crop in the lowland ecologies.

But the African lowlands are very complex rice ecologies. Lack of water control, iron toxicity, weeds, and highly destructive diseases and pests are some of the major challenges of lowlands to rice production. Yields from traditional rice varieties in this ecology are low, usually less than 1.5 tonnes per ha or around 40% of the world average.

To develop suitable varieties, a breeding program was initiated, focusing on crossing specific varieties of the African rice that were known for their resistance to lowland stresses with popular—but susceptible—Asian rice varieties.

The Asian rice O. sativa has two main strains, japonica (traditional rainfed or ‘upland’ rice and indica (traditional irrigated or ‘lowland’ rice). In the creation of Upland NERICA, japonica varieties were used in the crosses, while for developing the Lowland NERICA, the indica varieties were used.

The initial problem was hybrid sterility (infertile offspring of the crosses). The sterility blockage was overcome by backcrossing (crossing the hybrid to O. sativa to restore fertility).

Initial NARS partners were Burkina Faso, followed by Togo and Mali. Lowland lines were evaluated in these countries. The ROCARIZ rice network facilitated the shuttle-breeding approach to accelerate the selection process and achieve wide adaptability of the Lowland NERICAs.

The most promising Lowland NERICAs showed the low susceptibility to disease and insect attack, which is vital if they are to succeed in the hard-pressed lowland ecology. To reduce the time between on station trials and the adoption of the varieties, scientists conducted farmer participatory varietal selection (PVS) in collaboration with the national programs. About 60 lowland NERICAs have been selected by farmers through PVS.

The national partners who were closely involved in this process immediately saw the potential of these new crosses with yield potential of 6-7 tonnes per hectare and good resistance to major lowland stresses. This led to the official release of two lowland NERICAs in Mali, and four varieties in Burkina Faso in 2005.

Given the high potential of the lowlands in Africa, the new rice varieties are expected to make an even bigger impact than the original NERICAs.

WARDA scientist Dr Moussa Sié, who led this research received the Fukui International Koshihikari Rice Prize of Japan in 2006.

Facts and Figures on Lowland NERICA

• WARDA’s innovative partnership model, especially with the national programs of West Africa through the Rice Research and Development Network for West and Central Africa (ROCARIZ), has recently led to another breakthrough: the development of a new generation of NERICA varieties adapted to lowland rice ecologies.

• Sixty Lowland NERICA varieties, selected by farmers in several African countries through the Participatory Varietal Selection (PVS) process, have been named and characterized.

• The Lowland NERICAs have yield potential of 6-7 tonnes per ha and good resistance to major lowland stresses.

• Lowland NERICAs are being evaluated in about 20 African countries across West, Central and East Africa for different water regimes, in different integrated crop management scenarios. A second generation of Lowland NERICAs with improved plant height has already been developed.

• In West Africa alone, if out of a total estimated 5.3 million hectares, only 2 million hectares of lowlands is grown to rice, producing an average yield of only 3 tonnes per hectare the region could easily stop its costly rice imports.

• The lowlands, therefore, offer great potential for the sustainable expansion and intensification of rice and can help to feed the growing population in the region. Given their high potential, the Lowland NERICAs are expected to make an even bigger impact than the upland NERICA.

Local Names of Lowland/Irrigated NERICA

The Gambia

In The Gambia, local names for the Lowland/Irrigated NERICA are given based on the people who have introduced it. So, some of the names are:

• Sambou mano

• Sulayman Jallow mano

• Gaye mano

Lowland NERICA Pedigree Names