Thanks to Hugh Warwick for this
Date Posted : 29 May 2001
Mr Carl Smith
University of Greenwich
020 8331 7663
4,000 Year Old Technology Inspires Eco-Friendly Pest Control
Farmers whose stored grain is lost to insects could benefit from eco-friendly pest control technology originally used in China 4,000 years ago. An award-winning team of researchers, based at the University of Greenwich's internationally renowned Natural Resources Institute (NRI), is exploiting the unusual pest control properties of diatomaceous earth (DE). Readily processed into fine dust and mixed with stored grain, DE absorbs the waxy layer of an insect's exoskeleton, resulting in dehydration and death.
Derived from the fossils of phytoplankton (a type of diatom), DE is a naturally occurring chalky rock found in many parts of the world. Trials carried out in Zimbabwe have proved that this rock is not only as effective as conventional organophosphate pesticides, but is also far safer, being virtually non-toxic to humans and other mammals. It has been shown to control insect pests that damage stored grain for up to eight months.
It is believed that DE was originally used in pest control by the Chinese more than 4,000 years ago, after they observed birds and mammals bathing in dust to rid themselves of parasites.
"Farmers in Africa are concerned about the health implications of mixing conventional pesticides with their stored grain," says NRI researcher, Tanya Stathers. "The cost is also prohibitive for many farmers and the pesticides are not easy to obtain. DE could offer a locally available, cheaper, healthier and more environmentally friendly alternative. It is already being used in large-scale grain treatment in Australia."
"Reducing storage losses not only means that developing world farmers are less vulnerable to hunger and famine," continued Ms Stathers, "but it also allows them to store their harvest longer, which can mean increased income as they can choose when to sell any surplus."
Tanya Stathers was recently recognised as one of Britain's top young scientists, engineers and technologists at a House of Commons reception. She was chosen as winner of a De Montfort Prize for her efforts to improve the lives of poor African farmers using DE technology.
"While surplus food stocks rot in the open, thousands die of starvation and hunger. And as if this is not enough, the government has allowed the sale of foodgrains at a throw-away price to traders and merchants for export when people in the country are waiting endlessly for two square meals a day!" - Devinder Sharma