Lagos, Nigeria
June 29, 2009
by
Semiu Babalola,
SciDevNet
The elimination of deadly
aflatoxin, which contaminates food crops in Sub-Saharan Africa,
is a step closer now scientists have shown that a control method
works well in large-scale field trials.
Aflatoxin is a poison produced by the fungus Aspergillus flavus.
It contaminates crops such as maize, ground nuts, cassava and
yam, either in the field during times of stress — such as
drought or insect infestation — or as a result of poor storage
conditions.
More than 4.5 billion people in developing countries may be
chronically exposed to aflatoxin in their food, putting them at
risk of diseases such as cancer. Africa also loses about US$450
million in lost revenue from contaminated export grain.
Scientists from the Nigeria-based
International Institute of Tropical Agriculture (IITA), the
United States Department of Agriculture and the
African Agricultural
Technology Foundation in Kenya have been working together to
develop a biological control method to reduce the amount of
aflatoxin contamination in maize.
A study in 2007 (see Biological control saves maize from toxic
invasion) showed that using A. flavus strains that do not
produce the toxin to outcompete their toxin-producing cousins
can dramatically reduce aflatoxin concentration.
In the past two years, larger field trials have been conducted
at 11 sites using a mixture of four benign strains.
Ranajit Bandyopadhyay, a plant pathologist at IITA, told
SciDev.Net that this biocompetitive method reduces contamination
by 60–99 per cent. "[The trials] proved the robustness of the
technology in many growing conditions and gave us more
confidence about upscaling the technology widely in Nigeria," he
adds.
Farmers in Burkina Faso, Kenya, Malawi, Mozambique, Senegal and
South Africa are showing interest in the technology but the
benign strains developed are indigenous to Nigeria and may not
be suitable for other countries, say the scientists.
IITA researchers will begin further field trials in Nigeria on
another 100 hectares in August.
"Finding a donor that can fund this technology on a large scale
is a priority," says Bandyopadhyay.
But Niyi Olayiwola, an agricultural economist at the Nigeria's
Development Policy Centre, says that getting farmers to use the
technology may not be easy. "It is a good development but
farmers value their own traditional ways of doing things,"
Olayiwola says. |
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