New Rice for Africa

Offers Hope to Women Farmers and Millions More

 

 

Bintu is typical of West Africa’s 20 million rice farmers—most are women. Bintu farms about 1 hectare in southern Côte d’Ivoire, or the Ivory Coast. She’s bound to an environmentally degrading, slash-and-burn farming system.

 

 

Bintu clears brush from new land, then plants rice seeds of the Asian rice species that entered Africa about 450 years ago. But Asian rices—developed for high-input irrigated farming—can’t compete with the weeds on Bintu's rainfed farmland, which soon take over. So, after a crop or two, Bintu must clear more land.

She would rather plant the traditional African rice species that her ancestors grew. It has wide, droopy leaves that smother weeds, and has thrived in harsh environments for 3500 years. The African rice also resists drought, acid soils, and local pests that plague the Asian rices.

Bintu also likes how the African rice tastes. It’s served at weddings and festivals.

But Bintu can’t plant her traditional African rice, because it doesn’t produce enough to feed her family—much less enough to sell surplus grain.

For years, scientists have dreamed of combining the ruggedness of the African species with the productivity of the Asian species. But the two are so different, attempts to cross them have failed. Until now.

Advances in agricultural research in recent years have helped scientists cross the two species—a breakthrough that is changing Bintu’s life. Using a technique called embryo-rescue, scientists are able to assure that crosses between the two varieties survive and grow to maturity. The new rice for Africa, like its African parent, smothers grain-robbing weeds, and resists drought, pests and problem soils. It also inherited higher productivity from the Asian species, and can double production with just a few inputs.


Rice in West Africa

Nowhere is the struggle for food more desperate than in West Africa—home to 240 million, one of every three persons on the continent. More than half the population survives, somehow, on less than one US dollar per day.

"Keep in mind that ‘food’ means ‘rice’ for many people in West Africa today," says Dr Kanayo F. Nwanze, director general of the West Africa Rice Development Association (WARDA), based in Côte d’Ivoire. It was WARDA that developed the rices, dubbed NERICAs (NEw RIce for AfriCA).

"Ironically, rice was considered a luxury food in West Africa only two decades ago," Nwanze adds. "Today, it’s the staple." Rice now contributes more calories and protein than any other cereal in humid West Africa, and about the same as all roots and tubers combined. Demand for rice is growing faster here than anywhere in the world.

In three decades, rice imports have increased eight-fold, to over 3 million tonnes a year, at a cost of almost US$ 1 billion.

About 40% of West Africa’s 4.1 million hectares of rice is upland, or dryland, grown like wheat or maize. Fertilizer and pesticide use is minimal, and yields are only about 1 tonne per hectare.


Breeding strategy

"The African and Asian species evolved separately over millennia," explains Dr Monty Jones, WARDA rice breeder. The African species lodges, or falls over, when grain heads fill. It also shatters easily, wasting more precious grain. The higher-yielding Asian species has largely replaced its African cousin.

West African farmers in rainfed (dryland) areas can’t grow the semidwarf rices that have revolutionized irrigated production in Asia, because they don’t compete well with weeds, or tolerate drought and local pests. And African farmers are too poor to invest much in herbicides, other pesticides, or fertilizers.

In 1991, Monty Jones initiated a biotechnology-based program to combine the best traits of the Asian and African rices. Key to the effort were gene banks that hold seeds of 1500 African rices—which had faced extinction as farmers abandoned them for higher-yielding Asian varieties.


Traits of the
New Rice for Africa

Scientists were testing the new rice for Africa—progeny of African–Asian crosses—in rainfed conditions by the mid-1990s.

"Genetic differences in the two species made breeding difficult—but also gave the new rices high levels of heterosis or hybrid vigor," Jones says. Heterosis is the phenomenon in which the progeny of two genetically different parents grow faster, yield more, or resist stresses better than either parent.

Weeding accounts for 30 to 40% of all labor—mostly by women and children—invested in a West African rice crop.

The NERICAs inherited wide, droopy leaves from their African parent, which smother weeds in early growth. That reduces labor, and allows farmers to work the same land longer, rather than having constantly to clear new land.

The structure of the panicles, or grain heads, has also been changed. Panicles of the African species produce only 75-100 grains. The new rices inherited, from their Asian parent, longer panicles with ‘forked’ branches, and hold up to 400 grains.

Like their Asian parent, the new rices hold grains tightly, not allowing them to shatter. They produce more tillers than either parent, with strong stems to support the heavy grain heads.

The new rices outyield others with no inputs—but respond bountifully to even modest fertilization.

"In trials, we’re getting yields as high as 2.5 tonnes per hectare at low inputs—and 5 tonnes or more with just minimum increase in fertilizer use," Jones says. "We’re talking about 25% to 250% production increases."

The new rices mature 30 to 50 days earlier than current varieties, allowing farmers to grow extra crops of vegetables or legumes. They’re taller than most rices, which makes harvesting easier—especially for women with babies strapped to their backs. They resist pests and tolerate drought better than the Asian rices—vitally important for rainfed-rice farmers. The new rices grow better on infertile, acid soils—which comprise 70% of West Africa’s upland rice area.

They also have about 2% more body-building protein than their African or Asian parents.

Dr Susan McCouch of Cornell University and the Rockefeller Foundation Rice Biotechnology Program is helping develop a molecular map of the new rices, plotting genes that control traits like droopy leaves.

"Using biotechnology to exploit genes from the African species could significantly increase global biodiversity in rice," McCouch says.


Spread and hope for the future

More than 1300 farmers participated in a 1998 program to start the new rices in Guinea, followed by a 1999 national seed increase and farmer awareness program. Average farm yields are rising from about 1 tonne to more than 1.5 tonnes per hectare with low inputs—and at least double that with good management and intermediate inputs.

WARDA projects that farmers will grow the new rices on almost 5000 hectares in Guinea in 2000, and 330,000 ha by 2002.

Several new NERICA rices, yielding at least 25% more than conventional varieties, will be released in West Africa in 2000. Research shows that 10% adoption in just three countries—Guinea, Côte d’Ivoire and Sierra Leone—will return an extra US$ 8 million to farmers per year. Adoption by 25% of farmers will return $20 million.

The new rice for Africa may also help farmers who grow upland rice on 17 million ha in Asia, and 4 million ha in Latin America.

 

For more information:

          

           Contact Guy Manners of WARDA at g.manners@cgiar.org

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