Less pesticide, more income from cotton
With "cotton ecosystem analysis", Asian farmers learn to study pests
close up in their fields and use insecticides only when necessary
Cotton is king in Asia. China, India and Pakistan alone account for almost 60% of the global cotton harvest and more than 70% of the world's cotton growers. Cotton in Asia is predominantly a crop of the poor, providing the main source of income of more than 100 million low-income, small scale farmers. Cotton processing provides jobs for millions of factory workers, many of them women. Little wonder, therefore, that cotton production is an important part of rural development strategies in many Asian countries.
But cotton production often involves intensive use of pesticides, mainly insecticides, which can pose a serious hazard to the health of farmers and consumers, agro-biodiversity, drinking water and ecosystems. In Asia, the use of synthetic pesticides - many of them classed as "highly hazardous" and banned in developed countries - increased exponentially with the introduction of improved cotton varieties and hybrids, which are higher yielding but also more susceptible to pests than traditional cultivars.
As pests developed resistance, pesticides become less effective and farmers began applying them with greater frequency, aggravating the economic, environmental and social costs. In the late 1990s, insecticides accounted in some Asian countries for an estimated 40% of the cost of cotton production, which not only limited profitability but forced many farmers to take out ruinous, high-interest loans to pay for them.
Alternative strategies. But there is also good news. Phytosanitary standards in international trade, growing consumer awareness, and concern over the degradation of natural resources have all prompted a growing number of cotton producing countries in Asia to limit pesticide use and adopt alternative strategies for protecting those valuable cotton plants against pests.
One successful approach is Integrated Pest Management (or IPM), a knowledge-based strategy that seeks to reduce the use of pesticides by preventing pests from becoming a threat. It trains farmers to monitor their field for potential outbreaks and use a combination of biological, cultural and - when necessary - chemical controls to manage pest damage by the most economical means, and with the least possible hazard to people and the environment.
IPM proved itself during the 1980s, when Indonesia faced widespread pest outbreaks in its rice fields, provoked by massive overuse of subsidized pesticides. While the government sharply reduced the distribution of the chemicals, the UN Food and Agriculture Organization supported the creation nationwide of Farmers' Field Schools (FFS), where small groups of farmers joined participatory open-air training sessions to learn IPM techniques. The result was a general reduction in pesticide use, by as much as 50% in some areas.
The approach was applied to cotton in 1999, when FAO and the European Union launched a five-year regional programme covering Bangladesh, China, India, Pakistan, the Philippines and Vietnam. The programme developed "cotton ecosystem analysis", in which participants meet once a week during the cotton season and, in small groups, make detailed observations of two study plots - an IPM plot and a "farmer practice" plot. By comparing notes and drawings of what they observe, the farmers become better decision makers and field managers, discovering, for example, that not all pests and not all pest population levels require control at all.
ABC of IPM
Integrated Pest Management uses a variety of practices to reduce the need for chemical pest control. They include:
• Cultural - e.g. using pest-resistant local crop varieties, crop rotations and intercropping
• Mechanical - heat sterilizing soils, culling insect pests by hand or machine
• Biological - using natural products for pest control, enhancing pest predator populations
• Biotechnological - using pheromones for a more targeted and effective pest control
Higher yields, profitability. Strengthening farmers' ecological knowledge and control over management of their fields has had important economic and social benefits. In India, farmers in one area reduced the seasonal application of active pesticide ingredients from more than 1000 ml to just 250 ml per hectare. Economic evaluation showed that the gross margin income of cotton farmers practising IPM rose by as much as 23% thanks to higher yields and reduced spending on pesticides. In Pakistan, 12% of trained FFS farmers escaped from poverty thanks to higher crop profitability. At the same time, reducing farmers' exposure to pesticides led to a 50% drop in cases of acute poisoning among field workers at some of the project sites.
IPM may have a role even in fields sown with genetically modified BT cotton, which contains a gene that produces the Bacillus thuringiensis toxin fatal to some species of caterpillars. BT cotton was introduced to reduce the need for chemical pest control, and it is generally accepted that it has contributed to a significant reduction in insecticide use.
However, recent outbreaks of secondary pest infestations, such as mealy bugs in North India, have led to government calls for farmers to revert to pesticides. Furthermore, the effectiveness of BT cotton depends on preventing development of resistance in bollworm, the most serious cotton pest - that is why it is mandatory, but practically impossible on small plots, for farmers growing BT cotton to plant 20% of their land with the non-BT hybrid. By addressing the emergence of previously unproblematic insects, IPM management can add significant value and sustainability to the achievements of BT cotton.
adapted from an article by
Cristina Mancini and Francesca Mancini
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