Farmers often believe that highly visible insects are responsible for large yield losses in rice, and direct much of their attention to leaf-feeding insects such as leaf folders. However, these insects usually do not reduce yields.
"Rice crops with leaf damage generally recover," says Heong. "Pest management is more than technology development. A huge gap currently exists between what farmers know and what they need to know to make good decisions in pest management."
Research in Chainat and Lop Buri provinces in Thailand indicated that 76 percent of the farmers surveyed, spray in the first four weeks after planting, but according to Khun Lakchai Meenakanit, an agricultural extension specialist with the Thai Department of Agricultural Extension: "These applications are unnecessary." Several years ago, rice farmers in Thailand experienced problems from a pest called the brown planthopper. Scientists now discovered that this pest is a secondary problem stimulated by insecticides.
Experts have also found that rice farmers in the region continue to use highly toxic chemicals such as methyl parathion and monocrotophos. The World Health Organization classifies both as highly hazardous to human health, causing heart conditions, nervous system disorders, and even death after continued exposure. Both chemicals are banned in the United States, Europe, and Japan.
Recently, forty scientists from Cambodia, China, India, Indonesia, Lao PDR, Malaysia, Philippines, Sri Lanka, Thailand, and Vietnam met in Bangkok for an IRRI workshop to discuss the pest management perceptions and practices of farmers in Asia. Khun Peecharat Wannapee, director general of the Department of Agricultural Extension appealed to participants to find ways to help farmers reduce the unnecessary use of insecticides. Khun Mechai Viravaidya, Chairman of the Population Community Development Association (PDA), emphasized the need to communicate scientific knowledge to farmers, and to explore the use of media, community development organizations, and other means, to reach as many farmers as possible. IRRI will publish a book on research findings from the ten countries.
IRRI has adopted integrated pest management (IPM) as its guiding concept for research to develop better pest management tools and strategies. The objective of IRRI's IPM research is to derive, evaluate, and develop principles, techniques, tools, and knowledge that enhance the decision making skills of farmers, extension specialists, researchers, and public administrators. Intensive studies in the different rice ecosystems on the interactions among plants and their pests and predators have been carried out by IRRI researchers.
In addition, research on the economic and health impacts of various control tactics has been done. Based on these findings, IRRI strongly endorses IPM based on ecological principles in which natural mechanisms and processes, including host plant resistance, are fully exploited to reduce economic losses to farmers.
IRRI is working closely with national and international organizations to promote and implement IPM by generating the knowledge needed including an understanding of the decision-making processes of farmers.