Press Release February 2003

The trend has been confirmed in surveys by both the Philippine Rice Research Institute (PhilRice) and the Philippines-based International Rice Research Institute (IRRI). The research revealed that insecticide use by farmers in central Luzon peaked in the mid-1980s and is now at an historic low, though some farmers still use insecticides as a last resort to prevent serious crop loss.

The research also shows that herbicide use peaked in the early 1990s and has slowly declined since then. Farmers continue, however, to use herbicides more often than insecticides.

Particularly encouraging is the surveys’ finding that, despite the steep decline in insecticide use, rice farmers in the region were able to increase their yields over the same period, seeing them rise from an average of 2.75 tons to close to 3.25 tons per hectare by 2002. “This result is testimony to the success and hard work of PhilRice and the other groups in the Philippines who over many years have been promoting the use of integrated pest management,” commented IRRI Director General Ronald P. Cantrell.

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.

“The surveys also show 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,” Dr. Cantrell said. “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.”

“The simple fact is that, in the rest of Asia, most insecticide use on rice is a waste of the farmers’ time and money,” said Gary Jahn, an insect ecologist at IRRI. “This is because it is applied at the wrong time, when it will make no difference to the crop’s yield. Or it is applied at the right time but in the wrong way, due to either poor application techniques, incorrect dosages or even selection of the wrong chemical.

“What we hope to learn next is why the farmers of central Luzon have learned these lessons so much more quickly than farmers elsewhere,” Dr. Jahn added. “Clearly the work of IRRI, PhilRice and other groups has helped to educate farmers about how to use insecticides correctly. We need to take these strategies and see if they can work as well in other important rice-producing regions in Asia.”

Reductions in insecticide use have been achieved in other countries, but in most cases, after a period of usage decline, farmers have started to increase their use again. Central Luzon remains one of the region’s cleanest rice bowls. PhilRice 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. The institute’s research also revealed savings of up to 1,000 pesos per hectare for some farmers who had successfully reduced their insecticide use.

PhilRice stressed, however, that irrigation played an important role as well. “Farmers in central Luzon are able to practice synchronous planting because water is released at the same time,” explained Artemio Vasallo, a PhilRice training specialist who has played a key role in the institute’s IPM training programs. When all the farmers in an area plant and harvest at the same time, Dr. Vasallo explained, the post-harvest “famine” experienced by insect pests sharply slashes their populations. “Thus, the incidence of pests is more manageable in central Luzon than in Iloilo or some parts of Mindanao, where asynchronous planting is more prevalent.”

As mentioned above, campaigns aimed at helping farmers reduce the unnecessary use of chemicals on their crops have enjoyed successes elsewhere in Asia. Last year, an innovative campaign that promises to help protect a million rice farmers in the Red River Delta of Vietnam from the harmful effects of dangerous insecticides won one of the world’s major environmental prizes. The campaign - which is being jointly advanced by a team of Philippine and Vietnamese scientists - will build on a groundbreaking effort that has sharply reduced pesticide misuse in Vietnam’s Mekong Delta.

The collaborative effort, which received the US$25,000 Saint Andrews’ Environmental Prize, is led by K.L. Heong, a senior entomologist at IRRI, M.M. Escalada, a professor of development communication at the Philippines’ Leyte State University (currently seconded to IRRI as an international research fellow with the impact workgroup of the Irrigated Rice Research Consortium), and Nguyen Huu Huan, the vice director general of Vietnam’s Plant Protection Department.

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. 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.

After testing their campaign in the Mekong Delta, where almost 2 million rice growers were persuaded to cut back on using harmful and unnecessary farm chemicals, the research partners launched, on World Environment Day last June, a similar, on-going campaign in central Thailand’s Sing Buri Province. Now they will use the Saint Andrews’ prize money to extend the campaign to another million rice farmers in the Red River Delta.

“We had been studying ways to implement such campaigns as this in other countries, but clearly we won’t have to do this in central Luzon,” Dr. Cantrell said. “For many years, IRRI has been criticized by some groups for promoting the use of chemical inputs, but this research shows clearly that the rice farmers closest to the institute - some of whom are in fact our neighbors - depend on insecticides less than almost anyone else in Asia.”

Download a graphic showing the results of the central Luzon survey

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