Biotechnology at work
Case studies from around the world show how biotech can be deployed to help the poor and hungry
Biotechnology has real potential to help meet the challenges of feeding a growing world population. Here, three examples from the developing world show how biotech has been successfully tapped in order to meet the needs of small-scale farmers.
Disease-free bananas in Kenya
In the developing world, bananas are an important food staple and their cultivation is a major source of employment. However production is in decline in many regions as a result of pest and disease problems that cannot be managed due to the high cost of pesticides and their negative environmental effects.
Complicating matters is the fact that banana is produced clonally; the use of diseased mother plants to produce new shoots often gives rise to diseased offspring.
In Kenya, biotechnology is being tapped to tackle the problem. Via a technique known as micropropagation, an original banana shoot tip is heat-treated to destroy infective organisms and then used through many cycles of regeneration to produce daughter plants. A single selection of tissue can be used to produce as many as 1 500 new, disease-free plants through ten cycles of regeneration -- without the use of any pesticides.
Pearl millet in India
Pearl millet is a cereal grown for foodgrain and straw in the hottest, driest areas of Africa and Asia. In the 1960s, high-yielding varieties of pearl millet were developed in order to help poor farmers increase production -- but these varieties proved to be vulnerable to a plant disease known as downy mildew.
In India, where around 9 million hectares of land are dedicated to pearl millet, nearly 70 percent of that cultivation involves high-yielding varieties, and downy mildew epidemics that wipe out crops are common. But using biotechnology, the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) has been able to help Indian farmers cope with the problem.
First, ICRISAT mapped the genomic regions of pearl millet that control downy mildew resistance, grain production and straw yield under drought conditions. The organization then took that knowledge and used conventional breeding techniques as well as marker-assisted selection to derive two new varieties of the crop. These have performed as well as or better than their parent lines in terms of grain and straw yield, and possess a markedly improved resistance to downy mildew.
Bt cotton in China
Conventional cotton production relies heavily on chemical pesticides to control caterpillars and other insect pests. Indeed, it is estimated that cotton production consumes about 25 percent of the agricultural pesticides used worldwide.
Transgenic cotton -- which contains a gene from the bacterium Bacillus thuringiensis (Bt) that provides resistance to some insect pests -- offers an alternative to chemical pesticides.
Bt cotton was first grown in Australia, Mexico and the United States in 1996 but has since been introduced commercially in six other countries: Argentina, China, Colombia, India, Indonesia and South Africa.
In China 4 million small-scale farmers are currently growing insect-resistant Bt cotton on about 30 percent of the country's total cotton area. Yields for insect-resistant cotton are about 20 percent higher than for conventional varieties, and pesticide use has been reduced by an estimated 78 000 tonnes -- an amount equal to about one-quarter of the total quantity of chemical pesticides used in China. At the same time, Chinese cotton farmers cultivating Bt strains reported fewer instances of pesticide poisoning than those growing conventional varieties. The use of Bt has been especially effective when employed as part of an integrated pest management programme.
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