Fungus fights cocaine trade

The fungus aims to kill only coca plants

By BBC Science's Corinne Podger

The latest weapon in the fight against the cocaine trade may be a common fungus.

The Colombian Government is considering using a strain of the Fusarium fungus, which attacks and kills coca plants - the source of cocaine.

But environmentalists are worried that the fungus, which has never been tested in Colombia, might damage other plants.

Coca growing is also a problem in Brazil

Governments in Colombia, Brazil and Peru already use herbicides to kill coca plants but farmers can simply move to other areas and plant new crops.

But if the coca-killing fungus, known as Fusarium oxysporum, is introduced into Colombia, it is expected to gradually become endemic across the entire country.

This would leave nowhere to hide and because it can survive in soil for many years, it could continue to attack coca plants for decades to come.

Million dollar trial

In a report in the magazine New Scientist, the Colombian Government is negotiating with the UN's international drug control programme to run field trials of the fungus, although a final decision to go ahead has yet to be made.

The trials would cost $23m, funded by the UN and the US.

Species of the Fusarium fungus are found all over the world, but the coca-attacking strain was discovered at a US Government research station in Hawaii after it infected an experimental coca plot.

One of the scientists involved, plant pathologist Brian Bailey at the US Department of Agriculture, said: "I think there's a good possibility it will work. But it's never been field-tested outside of Hawaii."

Rainforest could be destroyed if growers are driven deeper into hiding

However, he said smaller trials have not shown other plants are susceptible to infection.

But conservationists such as the Transnational Institute think tank, based in the Netherlands, remain opposed to the trials.

The Institute's Martin Jelsma said: "The main concern is that this is introducing yet another agent in the forced eradication programme that has done enough damage already. It will lead to more deforestation and more migration, displacing people even deeper into the Amazon."

He added that if the fungus does become endemic in Colombia, there is no guarantee that other plants will be safe.