Rethinking IPM: Strategies for Sustainablility
Chemical pest control is often self-defeating. As pesticide doses increase their effectiveness is diminishing. So far, throughout the world, 450 species of insects and mites, 100 species of plant pathogens and 48 species of weeds are now resistant to one or more pesticides. Natural enemies fall victim to pesticide use. Consequently, previously harmless organisms become pests.
Insects are not the only casualties of insecticide use. About eighty percent of pesticide related deaths occur in developing countries, even though these countries use less than 20% of all pesticides in the world.
IPM offers a viable alternative to chemical pest control. This approach includes the manipulation of planting and harvest dates, crop rotation and vegetation management to enhance natural pest control. It also includes breeding plant varieties with some pest resistance, introducing or conserving the pests' natural enemies, and using chemicals prudently based on sound, long-term environmental and economic planning. Governments can provide support for IPM through legal restrictions on chemical use, and through public activities and policy guidelines to enhance environmental conservation. Within this general framework, practitioners have developed specific IPM strategies for their particular circumstances.
Is IPM Sustainable?
IPM practices are not always self-sustaining. If plant protection methods require periodic human or capital input, they are not self-sustaining. Biological controls and structural changes in a farm landscape that increase biological diversity and maximize natural enemies are self-sustaining. Designing self-sustaining methods may require far-reaching structural changes in agricultural and economic systems.
A sustainable approach to IPM means using local production inputs, selecting well-adapted germplasm, increasing species diversity, coordinating crop production with other rural enterprises, involving farmers in planning, experimentation and evaluation, using pesticides prudently, and encouraging community participation and decision-making.
Ironically, traditional farming methods may lead to better pest management than so-called modern practices. Such traditional practices include mixed intercropping, selective weeding, and leaving natural vegetation around the edges of small, cultivated plots. Ensuring sustainable IPM means taking into account the knowledge and experience of farmers as well as scientists. Such systems must also be coordinated with broader programs in land and water management, public health protection, socio-economic development and conservation of biodiversity. This calls for a broad interdisciplinary approach.
To combine the knowledge of western trained scientists and farmers, IPM practitioners must reject arrogant dismissals of 'non-scientific' knowledge without adopting the naive view that farmers always know best. Also, practitioners must use innovative methodologies to actively involve farmers in observation, experimentation and adaptation of general IPM principles to local conditions. When farmers meet scientists on equal terms, both gain.
Farmers Tell Scientists What To Do
It is often difficult for an outsider to gain access to the knowledge and experience of farmers. The Participatory Rural Apprasal (PRA) approach allows access to this knowledge. PRA methods use semi-structured group interviews and ranking exercises to bring farmers' knowledge and priorities into the IPM research and planning process. In Andhra Pradesh, India, for example, farmers compared four pest-resistant pigeonpea varieties bred at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT). They evaluated the pigeonpea based on criteria that they determined: taste, seed yield, storability, and other aspects. Women farmers rejected one variety that had been officially released, because it tasted bitter. Using their own criteria, farmers selected three other varieties previously unreleased.
Research based exclusively on pest problems as percieved by scientists may not address farmers' priorities and needs. A more interactive approach suits resource-poor, risk-prone farming environments better than standard technology transfer methods, which frequently result in innovations that are rejected by the farmers. Farmers will not adopt a new high-yielding, pest-resistant crop variety if it increases risk, adds to labor demands, competes with other farm enterprises, or causes a host of other problems that researchers might not anticipate. Participatory methods encourage local innovation and adaptation, accomodate and enhance diversity, strengthen local capabilities and are more likely to generate sustainable practices.
Such an interactive approach is also appropriate for well-endowed farming environments that have been converted to high-input monocropping. In these areas, the goal is to turn industrial, green-revolution technologies into practices that are sustainable.
Teaching New Ways of Thinking
To implement IPM, practitioners need more than scientific competence. They need to learn new ways of thinking. Training programs must change attitudes and values as well as develop technical expertise. One proposed educational model includes role playing, conflict resolution and field exercises. Teachers are facilitators, catalysts and consultants in a learner-centered classroom environment. Students co-teach courses, design their own curricula and evaluation systems, and explore analytical thinking along with "open" divergent thinking.
Five changes in research, extension and policy formulation will contribute to the wider adoption of sustainable IPM systems:
1. Broaden the scientific method to synthesize diverse sources of knowledge.
2. Initiate an education process for IPM practitioners that emphasizes conceptual and attitudinal changes as well as imparting technical knowledge.
3. Re-examine, with the objective of discontinuing, all government subsidies on chemical pesticides.
4. Stop the export of banned pesticides without the prior informed consent of importing countries.
5. Increase support for IPM and field implementation.
Pimbert, Michel. 1991. Designing Integrated Pest Management for Sustainable and Productive Futures, Gatekeeper Series No. 29, International Institute for Environment and Development.