Trials to develop a virus resistance sweet potato through biotechnology have failed.
US biotechnology, imported three years ago, has failed to improve Kenya's sweet potato. This has confirmed critic's fears that bio-engineered techniques tried elsewhere may not be replicated in Africa with similar results.
The modified potato was launched in Kenya, in 2001 by US special envoy, Dr Andrew Young, who had flown into the country for the occasion.
Investigations, on the transgenic crop, by KARI's Biotechnology Centre, say the technology has failed to produce a virus resistant strain. "There is no demonstrated advantage arising from genetic transformation using the initial gene construct," says a report by researchers, Dr Francis Nang'ayo, and Dr Ben Odhiambo.
The transgenic potato was imported from Monsanto in the US to Kenya for tests. The initial genetic engineering work was done at the Monsanto laboratories, using virus-resistant technologies.
In a nine-year study, Monsanto had developed a coat protein responsible for virus resistance, and donated it to Kari, royalty free, to use in its sweet potato improvement programme.
"The transgenic material did not quite withstand virus challenge in the field," says the report, doubting whether the gene expression was adequate or it failed to address the diversity of virus in this region or just that the gene construct was inappropriate.
Actually, the report indicates that during the trials non-transgenic crops used as control yielded much more tuber compared to the trangenics. "All lines tested were susceptible to viral attacks."
The Kari results corresponded with an earlier study released by the Third World Network D Africa. The study, titled "Genetically Modified Crops and Sustainable Poverty Alleviation in Sub-Saharan Africa: An Assessment of Current Evidence", by Aaron deGrassi, of the Institute of Development Studies, University of Sussex, UK, had warned that the GM sweet potato introduced in Kenya did not address the crop's major problem - weevils.
The study offered new evidence against claims of the miracle potential of genetically modified crops for dealing with famine and poverty in Africa. After examining the impact of three genetically modified crops, sweet potato, maize and Bt cotton, on poverty alleviation in Africa it concluded that biotechnology does not address the real causes of poverty and hunger in Africa.
Now Kari's research on sweet potatoes has reverted to working with improved gene constructs based on Kenyan strain of virus. This questions the suitability of wholesale importation of foreign technologies.
It was hoped that the technology would boast one of the country's most important tubers with the widest regional distribution. It seems much more needs to be done.
Dr Young while launching the technology had said, "I don't believe that we live in this world for our crops to be destroyed. We have been given knowledge for the earth to make sense."
He had then described the continent as being, on the verge of a tremendous revolution. "With biotechnology, we are going to make a green revolution in Africa."
The sweet potato project had been approved by the Kenya Biosafety Council and mock-trials initiated in Kakamega, Kisii, Muguga, Mtwapa and Embu. But the Kari researchers say all is not lost because the experiment proves that the country has the capacity to handle transgenics in the field.
"It proved that KARI and Kenya by extension had the capacity to try the suitability of sophisticated biotechnologies," says Dr Odhiambo.
Unlike the more conventional Irish potato, the tuber is not only popular among rural communities in Kenya, but also lasts much longer after traditional processing. This makes the root tuber a more ideal crop for storage for dry seasons.
The average harvest of the crop in Kenya, however, has remained low due to a number of factors, including attacks by pests and the sweet potato virus disease. The yield losses resulting from the viral diseases, according to KARI, can be as high as 80 per cent.
Kenya's average sweet potato yield stands at six metric tons per hectare less than half the world's average 14 metric tons per hectare.
Gene modification is a relatively new technique in Kenya. Other less high-tech biotech processes such as tissue culture have been widely commercialized in crops like bananas, macadamia nuts and strawberries.
The transgenic sweet potato is not the only food crop improvement projects conducted between KARI and Monsanto. Other projects include insect-resistant cotton, and maize resistant to striga - a parasitic weed responsible for destroying up to half of yields in western and coastal parts of Kenya.
KARI is the main institute of agricultural research and technology transfer, in charge of providing such appropriate technology aimed at boosting agricultural productivity and livestock production.