Reducing pesticide use in Asia’s rice fields: the job is far from finished

 Gene Hettel   |  
(Photo: Gene Hettel)

(Photo: Gene Hettel)

For more than 25 years, Kong Luen “K.L.” Heong worked at the International Rice Research Institute (IRRI) as an entomologist, trekking across Asia to visit farmers and help them improve the management of rice pests, thus reducing their crop losses. This IRRI principal scientist, until his retirement in late 2013, was responsible for research on arthropod ecology and integrated pest management (IPM). He conducted pioneering research (see The pesticide paradox on Scribd) and won many awards, including the 2006 Third World Academy for Science Prize for Agriculture, for furthering IPM concepts and pushing for greater understanding of pest problems in rice among farmers, extension personnel, and governments alike. However, he told the following anecdote during his recent pioneer interview to emphasize that there is still much more to do.

“Lucky” farmer will still spray next season

Planthopper outbreaks, such as this one in Indonesia, can be triggered by high dependence on or misuse of insecticides. Such a scenario is certainly a threat to sustainable rice production. (Photo: IRRI)

Planthopper outbreaks, such as this one in Indonesia, can be triggered by high dependence on or misuse of insecticides. Such a scenario is certainly a threat to sustainable rice production. (Photo: IRRI)

“In Thailand, I went to observe an outbreak in farmers’ fields of the brown planthopper (BPH), the insidious insect pest that continues to devastate rice harvests across Asia. In one village, a farmer experienced a serious yield loss due to the BPH while his neighbor just across the road had a good crop with virtually no BPH infestation. Talking to both of them, I discovered that they used the same variety, planted it at the same time, and applied the same fertilizer. What did they do differently? The farmer who suffered the crop loss said proudly that he had sprayed eight times, but he still could not control the pest. His neighbor was almost too shy to tell me that he actually didn’t spray anything because he had been in the city and had just returned. So, I asked the farmer who did not spray, what lesson had he learned? He replied, ‘I was just lucky; next season, I will definitely spray.’”

Dr. Heong pointed out that farmers such as these are stuck in a broken system. They are really victims—paying for pesticides that they don’t need; yet, in the end, their crop is still severely damaged if not destroyed. They have no idea what happened to them! Sadly, this scenario is repeated too many times across Asia. There have been successes in reducing pesticide applications, especially in Vietnam (see Vietnam turns back a tsunami of pesticides). Here, the “Three Reductions, Three Gains” campaign and radio soap operas have successfully helped change the conventional wisdom on pesticide use among farmers and agricultural officials. However, the pressure on farmers to use pesticides continues to be relentless.

New false reasons to spray: hybrid rice and climate change

“Many farmers tend to remember the last thing they hear from anyone with a convincing story, such as a pesticide salesman,” said Dr. Heong. “For example, I have found farmers who, after they had undergone 16 weeks of training on how to manage their crops without spraying pesticides, started spraying again only 2 months later! When I asked one farmer why, he said, ‘Sir, we’ve been told that, since we are now planting hybrid rice, it is susceptible to pests and we must spray five times.’ So, all those weeks of training were wiped away by a wily salesman who told the farmers that hybrid rice is somehow pest susceptible. Of course, it is not, but that doesn’t matter.”

Another tall tale: pesticide pushers are warning farmers that climate change is here and, with it, new pests are arriving on the scene, which require insecticides to control them.

When an insecticide might be effective

Fr. Heong said that an insecticide can be effective only if the right chemical is applied with the right equipment at the right time and targeted to the right pest.

“Otherwise,” he said, “it is either completely wasted or, worse, it may actually cause more trouble, such as creating a predator-free environment in which the BPH can wreak its havoc on the rice crop. In the early stage of the crop (the first 40 days), chemical applications are absolutely unnecessary. Toward the later stage of the crop, there might be an occasion during which a field is invaded by a pest from an external source. A farmer then might effectively apply one, just one, targeted spraying to control such a pest.”

Myanmar: perhaps taking a different path

In November 2013, just a few weeks before his retirement, Dr. Heong and his team went to Myanmar to conduct a symposium on ecological engineering in rice. “The BPH threat in Myanmar is real because it’s next door to Thailand, where the pest is a serious problem right now,” he explained. “The good thing about this Southeast Asian nation, which has the potential to reclaim its title as a major rice exporter if not the top exporter in the next 10 to 20 years, is that most of its farmers spray very little because they have, up to now, been unable to obtain insecticides. However, with Myanmar opening up economically, many pesticide companies are, I would say, ‘invading’ the country. These companies are queuing up at the Department of Agriculture daily to get their products registered.”

This sudden influx of insecticides coming into Myanmar could possibly make farmers start using chemicals heavily—especially if the country’s existing pesticide laws and regulations are not well secured and implemented. “If this happens, the BPH will become a very serious threat,” Dr. Heong predicted. “So, the symposium aimed to influence the pathway of how pest management in the country is to be practiced, hopefully preserving ecosystem services (i.e., predators and natural enemies of the pests) rather than relying on the pesticide trap and ‘addiction’ that has befallen many farmers of Myanmar’s Asian neighbors.”

Since insecticide resistance in rice planthoppers is developing rapidly, Dr. Heong even rushed the printing of the greatly updated second edition of his book, Research methods in toxicology and insecticide resistance in monitoring of rice planthoppers to have it available during the symposium. “We want to get to Myanmar farmers and policymakers before the pesticide companies do,” he said. “IRRI is in a position to help Myanmar build a different path toward more sustainable pest management than the direction taken by its neighbor countries in the first Green Revolution. Although it will be a big challenge to stay a step ahead of the pesticide merchants, it will also be fascinating to follow this case study in the making.”

A quest after “retirement”

Although Dr. Heong has retired from IRRI, he will be pursuing a personal quest over the next 5 years. “I will focus on designing governing structures in countries such as Myanmar, Vietnam, Thailand, Indonesia, and others that will make scientific technologies—be they resistant varieties or new practices— more sustainable and viable in the face of how pesticide companies cleverly market their products,” he said. “Although pesticide use is indeed a pest management tool, the practice tends to overshadow all the other technologies that can help farmers.”

Science and other logical methods cannot compete with the pesticide marketers unless the rules that regulate these chemicals are enforced. “Unfortunately, most countries don’t have the governing structure required to do so,” concluded Dr. Heong. “I hope to help change that.”


Mr. Gene Hettel is the editor-in-chief of Rice Today.

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