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Pests, Pesticides and Modern Science
Posted: Tuesday, May 6, 2003

By Devinder Sharma

It took three decades for the International Rice Research Institute (IRRI) to realise the gravest mistake of Green Revolution - pesticides are unnecessary. But by the time the mistake was realised, pesticides had polluted the environment, poisoned the fertile soils, contaminated the ground water and taken a heavy human toll.

Not far from where IRRI is located, rice farmers in Central Luzon province in the Philippines, had gradually got disenchanted with the indiscriminate use of pesticides. From a peak insecticide use in the mid-1980s, it is now at an historic low. Contrary to what agricultural scientists and the chemical industry had maintained all these years, the decline in insecticides use has been accompanied by an increase in productivity from an average of 2.75 tonnes to 3.25 tonnes per hectare in 2002. It also resulted in savings on an average of up to 1,000 pesos per hectare for these farmers.

Equally significant is the scientific courage with which IRRI's director general, Dr Ronald Cantrell has accepted the reality: "It shows that the mistakes of the Green Revolution - where too much emphasis was sometimes put on the use of chemicals for pest control - have clearly been recognized and corrected," adding, "because of their toxicity, insecticides really should be used by farmers as a last resort, and we are very pleased to see that farmers have realized this for many years, especially here in the Philippines." His colleagues at IRRI are now equally critical of the extent and use of pesticides. Says Gary John, an ecologist: "The simple fact is that, in the rest of Asia, most insecticide use on rice is a waste of the farmers' time and money."

The Philippines is not the only country where farmers have proved the scientists wrong. In Vietnam, almost 2 million rice growers in the Mekong Delta have been persuaded to cut back on using harmful and unnecessary farm chemicals. The campaign - which was a joint effort of a team of Philippine and Vietnamese scientists - has sharply reduced pesticide misuse, and won the collaborative effort the US$25,000 Saint Andrews' Environmental Prize for 2002. The prize money is now being used to extend the campaign to another million rice farmers in the Red River Delta.

"What we hope to learn next is why the farmers of central Luzon have learned these lessons so much more quickly than farmers elsewhere," adds Dr. John. First launched in 1994 in the Mekong Delta - long one of the great rice bowls of Asia - the research and subsequent campaign marked a milestone in rice production for two reasons. IRRI says that first it clearly identified the damage caused by insecticide overuse, which kills off friendly insects and so encourages the pests they would otherwise help control, and it also developed a completely new way of communicating important information to farmers.

The basic premise of integrated pest management (IPM) is that no single pest-control method can be successful over a long period. Therefore, a mixture of biological, physical and chemical methods must be considered and integrated into a cohesive strategy designed to sustain a pest-management system. The ultimate goal of IPM is sustainable agricultural systems with minimal or no pesticide use, says an IRRI press release. One wonders when will this new found wisdom be applied in cotton, which alone consumes more than 50 per cent of the total pesticides used.

Well, if that is true, isn't it a fact that agricultural scientists had misled farmers all these years? Isn't it a fact that because of the over-emphasis on the use of chemicals to control pests, more problems have been created rather than being addressed? Isn't it a fact that besides polluting the environment, insecticides have changed the pest profile turning many minor insect species to emerge as major pests? Does it not mean that if scientists had learnt from farmers, probably they could have found simple time-tested technologies that wouldn't have destroyed the fertile lands?

For instance, in the State of Tamil Nadu, situated in the southern part of India, more than 8,000 farmers in some 10 districts have been using herbal pest repellents. Such has been the mental conditioning that no agricultural scientist, graduating from the land grant colleges, will ever accept the efficacy and utility of such an herbal spray. The result being that while expensive and unwanted pesticides are being promoted and pushed by the scientists and extension workers, farmers are looking for safe and ecological alternatives. While Philippino researchers say one of the key factors continuing to influence Philippine farmers is the return of fish, frogs and edible snails to their farms, confirming the positive environmental impact of IPM strategies, it may take some time for Indian agricultural scientists to see the writing on the wall.

A Karikali-based group in Tamil Nadu, prides in calling itself a university with multifarious ecological roles -- Vazhviyal Multiversity. Its herbal pest repellant is based on traditional knowledge listed in the scripture -- Vriksha Ayurveda. The repellant is prepared from the leaves of five plant species that are not eaten by cattle. These can vary from a place to place, but would ideally have neem, tulsi, and datura. The leaves are collected, cut into pieces and then pounded. The biomass is then put in an earthen pot filled with cow urine. The pot is kept in a compost pit for ten days, during which period it gets fermented. Filter the fermented solution with a cotton cloth, add ten times the quantity with water, and the herbal spray is ready.

The only catch being that the herbal spray is applied before the insects appear. Such simple technologies unfortunately do not find any mention in the agriculture textbooks and curriculum. The reason is simple: there is no industry behind it.

Numerous such technologies have been in vogue. But with the advent of modern science, which began to view everything traditional as backward and sub-standard, the collective wisdom of generations of farmers was lost. Such was the massive campaign to discredit everything that was time-tested for ages that modern science, its blind adoption, and extensive application became the essential ingredient for classifying farmers as ‘progressive'. The chemical industry, which gained commercially from the surge in widespread use, very cleverly used agricultural scientists as its promoters. By the time the scientists realized, and thanks to a concerted campaign by some civil society groups and organizations, the damage and destruction had been done.

The chemical industry has meanwhile moved into life sciences. The same industry now decries pesticides and sings virtues for the new 'promising technology' - genetic engineering. Pesticides are now being replaced with genetically modified crops, which perform the same functions. The tragedy is that agricultural scientists are being once again used as promoters of a technology, the negative impact of which have not been fully studied. Once again, agricultural scientists appear more than keen to take the farming community on a faulty garden path. And like the pesticides imbroglio, it may take decades before the disastrous implications of the cutting-edge technology, as genetic engineering is fondly called, become visible.

But then, who is responsible for and should be directed to pay for the clean-up operations to restore the sustainability of the lands and environment? Why shouldn't the ‘polluter pays' principle be applied to the Consultative Group on International Agricultural Research (CGIAR), which governs the 16 international agricultural research centers, and of course the multi-billion dollar chemical industry to pay for the environmental damages? It is time agricultural science is made accountable. It is high time that the CGIAR is directed to cough out the real cost of the environmental destruction its technologies have wrought. Modern science cannot be allowed a free play for un-necessary experimentation that does irreparable damage to the land and water that feeds the world. A beginning has to be made, the sooner the better.

(Devinder Sharma is a New Delhi-based food and trade policy analyst. Email:

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