IPM and the War on Pests

Article excerpt

In the long run, using chemical weapons against weeds and bugs is a losing proposition. So, what are the hopes for Integrated Pest Management?

"Paraquat and Nature working in perfect Harmony," proclaims the caption of a Malaysian ad for one of the world's more common pesticides. A photo shows lush green palm trees surrounding a farmer's hut. "Groundwater, rivers, streams and lakes are not affected by paraquat," the ad assures us. "Paraquat is not harmful to our wildlife." But paraquat's harmony is likely to be lost on those who know the pesticide well: farmers with paraquat-induced organ damage, relatives of farmworkers killed by paraquat, and biologists concerned about paraquat's effects on creatures from frogs to bees to horses.

The language of the ad reflects an underlying tension at the heart of pest management today. On one hand, the adverse economic, health, and environmental effects of pesticide use are ever more apparent. All over the world, governments and farmers look increasingly to Integrated Pest Management (IPM) - a strategy meant to minimize pesticide use by relying on natural methods of pest control - to break the pesticide addiction. Nine Asian nations now run comprehensive IPM programs, sponsored by the U.N.'s Food and Agriculture Organization. The United States alms to extend the use of IPM to 75 percent of its crop area by the turn of the century. And the World Bank has teamed up with the FAO to promote IPM through a newly established IPM Global Facility.

But despite the interest in reducing pesticide use, global pesticide sales actually rose in 1994 (the most recent year for which data were available) - and at the fastest rate in a decade. Further sales increases are likely, which means more poisoning of people and their land, more contaminated rivers and groundwater, and more farms whose natural pest defenses have been broken. Given these dangers, and given the interest in IPM, why are pesticide sales so strong?

The question has several answers, but the most significant is a shift in the definition of IPM over its nearly four decades of evolution. Today, the IPM faithful are an eclectic crowd, ranging from pesticide-shy organic farmers to pesticide manufacturers. IPM-ers subscribe to a diverse and contradictory set of creeds, some of which are nearly as unsustainable as a total reliance on pesticides. But practitioners who live by IPM's original message - that pesticides belong on the margins of pest management - argue that the time has come to reaffirm the strategy's founding principles.

THE PESTICIDE ADDICTION

Pest control is as old as agriculture, but widespread use of synthetic pesticides took off only after World War II, when these chemicals came to be regarded as near-miraculous solutions to one of the toughest problems in farming. Quick and easy to apply, pesticides were relatively cheap and powerfully effective. A new, "wonder" chemical used by Allied troops during the war to combat head lice and mosquitoes was later shown to be so effective at suppressing farm pests that it raised potato yields by more than half. The chemical - DDT - quickly became a basic piece of equipment in the pest-fighting arsenal. With the advent of such controls, it was thought, crop losses to insects, weeds, and diseases would soon be a thing of the past.

The farmers in Peru's Canete valley were among the first to learn otherwise. During the mid-1950s, they noticed that pesticides were losing their power over insects that attacked their cotton. Radical and continual increases in the doses seemed the only way to bring the bugs under control. What the farmers were witnessing was a kind of evolution in fast-forward: the few pests genetically equipped to survive the deadly rain became the progenitors of new generations, which inherited their protective genes. After a few cropping seasons, insects could practically swim in the chemicals that had decimated previous generations. …