SUCCESS STORY: Vietnam farmers cut pesticides, increase yields

Posted: 18 November 2003

The huge cost to farmers and the environment of the over-use of pesticides, is highlighted by an award-winning research project that has encouraged millions of Vietnamese rice farmers to reduce their use of pesticides. Maya Pastakia reports.

"Our project has exposed only the tip of the iceberg of the inappropriate use of agricultural pesticides in the developing world," says K.L. Heong, leader of the project.

He says that hundreds of million of farmers around the world continue to overuse pesticides, despite the emergence of exciting alternative strategies for pest control. As a result, not only do farmers and their families fall ill, but also secondary pest infestation can cause devastating crop losses.

Dr Heong, a senior entomologist at the Philippine-based International Rice Research Institute (IRRI), was in London to collect a Green Apple environment award for his team's work.

He is highly critical of local dealers in many countries who persuade poor farmers to use pesticides inappropriately. It is they, rather than the multilateral corporations who usually act responsibly by organizing education for farmers, that encourage over-use, he says.

"We convinced farmers to reduce their pesticide use, but no sooner did the project end, than the continued marketing of such products caused pesticide use to climb again."

False expectations

First launched in 1994 in the Mekong Delta - long one of the great rice bowls of Asia - the IRRI-led partnership's research and subsequent campaign marked a milestone in rice production for two reasons. First, it clearly identified the damage caused by misapplied insecticides, which kill off insect predators and so encourage the pests they would otherwise help control. Second, it developed innovative and effective ways to communicate important scientific information to farmers.

After testing their campaign in the Mekong Delta, where almost 2 million rice growers were persuaded to cut back on unnecessary chemicals, in 2001 the research partners launched a similar campaign in central Thailand's Sing Buri Province. On World Environment Day 2003, the partners expanded the project to the Red River Delta of northern Vietnam.

The project team realized that overuse and misuse of insecticides was largely due to years of aggressive pesticide marketing that plays to farmers' often misplaced fears.

"What appeared to motivate farmers to spray insecticides during the early stages were misconceptions, lack of knowledge and biased estimations of losses due to pests," Dr. Heong explained. "We found that the amount of rice farmers expected to lose if they didn't use insecticides was about 13 times higher than their actual losses. So we set out to find ways to change their attitudes, to motivate them to stop spraying -- or at least spray less."

Local radio

Because farmers depend on local radio broadcasts as their primary source of information, the researchers placed the farmers' radios at the heart of a media campaign. "We got a group of actors to play out a series of brief comedies, relating solid scientific facts through rustic situations to make the audience laugh," Dr. Heong explained. "We found these simple, humorous messages fixed themselves in the minds of thousands of farmers."

The radio dramas, supported by leaflets and posters, were aired first in Long An Province in 1994. Farmers learned from the broadcasts that research had shown that spraying in the first 40 days after sowing was a waste of time and money.

They were encouraged to test this for themselves with a simple experiment, spraying only part of their crop and comparing the yield from the sprayed and unsprayed portions. The benefits were soon obvious, and by 1997 the radio-and-poster campaign had been picked up by 11 other provincial governments and was reaching about 92 per cent of the Mekong Delta's 2.3 million farm households.

The results became clear with the analysis in 1999 of intensive surveys. Insecticide use had halved from an average of 3.4 applications per farmer per season to 1.7 applications. The number of farmers who believed that insecticides would bring higher yields had fallen from 83 per cent to 13 per cent. The number who realized that insecticides killed the natural enemies of rice pests had risen from 29 per cent to 79 per cent.

At the same time, the gross paddy output of the Mekong Delta increased from 11 million to 14 million tons per year. Dr. Heong believes that insecticide use can be halved again without affecting rice production -- but he and his partners fear that insecticide use will creep up again if the campaign is allowed to lapse.

Better training

"The only information most farmers get is advice from local suppliers to use more sprays," Dr. Heong says. "They think that every dollar they spend on insecticide is going to mean about $13 in their pockets at harvest time. In fact, that far exceeds reality. Even in a worst-case scenario, a seriously damaging pest infestation, they might benefit by only $4 from each dollar spent. And the worst-case scenario is a rare event.

"We should be training extension workers to communicate more effectively," Dr. Heong concluded, "to deliver correct information to the farmers and to motivate them to evaluate it objectively. We can't afford to leave pesticide education to those who profit by spreading misinformation about these chemicals."

  • Research has found that many Asian rice farmers apply insecticides at the wrong time and against the wrong targets. Farmers in Vietnam and elsewhere spray in the early crop stages because of leaf damage caused by caterpillars, beetles and grasshoppers -- damage that is highly visible but has little or no effect on yield. Some farmers spray routinely even though many modern rice varieties are bred for pest resistance and generally do not require further protection. By killing predators, these sprays disrupt natural biological control of pests and thereby create an environment favorable to outbreaks later in the cropping cycle, prompting farmers to spray even more.

The IRRI-led project, funding by the Swiss Agency for Development Co-operation, has helped many farmers reduce input costs by $30-50 per season. Key members of the collaborative team are, in addition to Dr Heong, Monina Escalada, a communications professor at the Philippines' Leyte State University, now seconded to IRRI; Nguyen Huu Huan, the vice director general of Vietnam's Plant Protection Department; and Vo Mai, Dr. Huan's predecessor.

Related links:

International Rice Research Institute (IRRI)

IRRI Library

Consultative Group on International Agricultural Research (CGIAR)

Future Harvest Foundation

Rice Knowledge Bank

Riceworld Museum and Learning Center