SciDev.Net

Empowering farmers to reduce mosquito populations and to use less pesticide will reduce malaria and other vector-borne diseases, according to a research paper published in the Bulletin of the World Health Organization (WHO) this month (July).

Vector-borne diseases, such as malaria and dengue fever, are a major public health problem in South-East Asia and agricultural practices can contribute to the health risk, says the WHO.

Use of pesticides increases mosquito resistance and destroys mosquito predators, leading to an increase in mosquito numbers and leaving toxic residues in food crops.

In June 2006, Henk van den Berg and co-authors evaluated 'farmer field schools', initiated in Sri Lanka on a large scale in 2002. They aim to help farmers manage both agricultural pests and insect disease vectors, such as malaria-carrying mosquitoes, with less emphasis on chemical methods.

The schools included field-based workshops, at which experts taught farmers about how mosquitoes, crops, farming practices and the environment interact, and how to manage the environment in a more sustainable way.  

By the middle of 2006, the project had involved 1000 families from 11 locations in 67 schools, report the authors.

They found that the project brought positive changes to the farming communities in terms of their agricultural practices and possibly their health.

Farmers that had attended the schools reported that they applied insecticide less frequently during rice production. They used alternative pest management methods such as draining mosquito breeding sites, using fish in the paddies to control larvae numbers and covering water containers.

The farmers were able to distinguish between disease-carrying and beneficial insects, and the larvae and adults of three different disease-carrying mosquitoes.

The authors suggest that future field schools work together with local anti-malaria campaigns, as well as local health staff. Teaching locals how to monitor mosquito-borne disease would result in better data and increase community ownership of projects.

According to Pakistani environmentalist A. Quraishi, a consultant to the World Wildlife Foundation, farmer field schools would be useful in Pakistan, because frequent pesticide use and insect resistance are a problem in the country.

The problem is so great that Brazil has stopped purchasing Pakistani cotton because of harmful chemicals present in the pesticides, Quraishi said.

"The experts are confined to their labs and there is no field workshop system. Overall, Pakistan's condition for agriculture and use of pesticides is among the worst in South Asia," he said.

Link to full paper in Bulletin of the World Health Organization

Reference: Bulletin of the World Health Organization 85, 501 (2007)