Asia rice output threatened by pesticide overuse

The unbridled manufacture and use of pesticides in Asia is raising the spectre of "pest storms" devastating the region's rice farms and threatening food security, scientists have warned. Increased production of cheap pesticides in China and India, lax regulation and inadequate farmer education are destroying ecosystems around paddies, allowing pests to thrive and multiply, they said.

The problem has emerged over the last decade and -- if left unchecked -- pests could lay waste to vast tracts of Asia's rice farms, according to scientists who took part in a workshop in Singapore last week. "There is increasing concern that the more we use pesticides in rice fields, it is actually making the pest problem worse," Australian scientist George Lukacs told AFP in an interview. Under pressure to raise yields to meet growing demand, poorly trained farmers tend to be over-reliant on the chemicals. "There are big outbreaks of pests or what they are calling in China 'pest storms' as a result of the over-application of pesticides," Lukacs said.

Rice is a staple throughout much of Asia, including the world's two most populous countries China and India, making the region vulnerable to soaring food prices and supply problems, economists say. Lukacs, a workshop co-organiser, said that in China and other parts of Asia, the unregulated use of chemicals has led to pests developing resistance.

The problem is compounded by indiscriminate application, which has destroyed the ecosystem surrounding the paddies, including the predators such as spiders and dragonflies that would normally keep pest numbers down.

"The predator pressure is gone and the pests don't respond (to pesticides) because they develop resistance very quickly," Lukacs said. Lukacs, senior principal research scientist with the Australian Centre for Tropical Freshwater Research at James Cook University, said responsibility lies with the pesticide companies, governments and local communities.

Once a pesticide is registered with a country's national authority, there is no monitoring of how it is used, he said. "It's a serious problem and the worst is that we haven't seen the full effects yet."

Source:AFP 2011-3-21