ngin - Norfolk Genetic Information Network

23 January 2002


1. Weedy killers to protect grain crops


1. Weedy killers to protect grain crops

18 January 2002
by Fred Pearce, BioMedNet News

Could farmers grow more crops by planting weeds? It sounds improbable, but agricultural researchers in three African countries are about to begin the first ever detailed investigation into just this idea.

The aim, says the Kenyan researcher behind the project, Zeyaur Khan, is to find new ways to fight the insect pests that menace grain crops by using selected weeds as a "fatal attraction - an alternative tasty food source that will lure and then kill them."

Funded by the World Bank and due to get underway over the next few days, the project will catalogue the biodiversity of hundreds of species of wild grasses still growing in wasteland in Kenya, Mali and Ethiopia. It will chart their often complex relationships with insects - and seek out those that could be used as natural pesticides.

Khan, who works for the International Centre of Insect Physiology and Ecology (ICIPE), based in Nairobi, figures that wild gramineae grasses, close relatives of modern cultivated cereals, often attract and repel the same pests. So these forgotten weeds make potentially ideal decoys, he says.

In collaboration with UK scientists at the Institute of Arable Crop Research at Rothamsted, he has already uncovered one such grass. Napier grass (Pennisetum purpureum), a common weed across much of Africa, attracts the moths of the stemborer, an insect whose larvae eat up to a third of maize crops in fields across the continent.

Khan works from ICIPE's research station at Mbita Point on the shores of Lake Victoria where he discovered that local stemborer moths prefer napier grass to maize. Moreover, the weed produces a sticky glue that traps and kills their larvae.

Farmers have been ripping up napier grass for years to clear ground to plant more maize. Inadvertently, this has encouraged the stemborer to invade their fields.

But in the past four years, Khan has persuaded thousands of farmers in Kenya and beyond to grow napier grass round their fields to attract and kill the stemborer. Yields have risen by up to 30% as a result, he says.

Now the idea is to find other similar relationships by researching other gramineae grasses long ignored by science. ICIPE's director, Dutchman Hans Herren, says the aim is both to help conserve the biodiversity of the fast-disappearing wild grasses and to help farmers practice cheap, chemicals-free pest management.

"We want to know what causes plants to attract and repel insects," Herren told BioMedNet News. "We know that napier grass attracts and kills stemborers. But do other grasses do similar things to important crops pests? We expect to find them. Then we can fight the insects where they are weakest."

The $2.5 million project is being paid for by the Global Environment Facility, based in New York.



January 22, 2002
Dow Jones Newswires [via Agnet]
Tim Todd

A dozen years ago and more than 3,000 miles from his Wisconsin home, Eric Triplett, according to this story, got an idea that could represent a new application of biotechnology to boost corn production that may eventually result in cornfields that don't need nitrogen fertilizer, a large component in corn production and a major cost factor for farmers.

The story says that Mr. Triplett, a microbial ecologist at the University of Wisconsin-Madison, is the leader of the first group of scientists to isolate and identify strains of plant bacteria that can increase corn yields by 5% to 10%, essentially giving U.S. farmers the potential for an additional 13 to 14 bushels per acre, based on the current average U.S. yield.

The scientists have applied for a patent through the Wisconsin Alumni Research Foundation.

Meanwhile, there is a licensing agreement with Agribiotics Inc., a relatively small, family-owned company in Cambridge, Ontario, that manufactures similar products for crops such as soybeans, peas, lentils and other crops. Alison McIver, who owns the five-year-old business with her sister, Hannah, was quoted as saying, ""It fits very well with the products we currently manufacture," adding that the company is looking for a strategic partner, likely in either the seed or chemicals sectors and hopes to have something available for farmers within a couple of years.

Mr. Triplett was cited as saying he started thinking about the potential in corn bacteria while guest lecturing at a Brazilian farm agency in 1990. While there, he said, Brazilian scientists showed him their work on sugar-cane bacteria that produce all of the nitrogen that crop needs. The story goes on to say that the product, however, doesn't involve the modification of genes -- a process seed companies have used to create soybeans able to withstand weed killers and corn able to resist certain pests but one that has also drawn the ire of some environmentalist groups.

"There has been no genetic modification of the strains at all," Mr. Triplett said of his project.
"Africa desperately needs investment in the so-called soft biotechnologies, such as alternative natural pesticides. But this work is losing prestige and funding because everyone is pushing genetic modification. I don't see GMs making an impact on food production in Africa within the next 10 to 15 years."
- Hans Herren, director of the International Centre for Insect Physiology and Ecology, based in Nairobi, quoted in 'GM crops threaten "amazingly encouraging" revival of sustainable agriculture'

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