International Rice Research Institute
Los Baños, Laguna, Philippines
In early September 2009, the Ministry of Agriculture launched a campaign in response to heavy planthopper damages in Suphan Buri, Ang Thong and Chainat provinces. (http://www.ricehoppers.net/2009/09/07/campaign-to-manage-planthoppers-launched-in-thailand/Campaign). The planthopper problem since then seems to have intensified. In late December 2009, the Ministry launched another campaign series, much larger and better supported by pesticide releases. The campaign theme was “D-Day Big Cleaning, Lock and Seal.” At the launch in Khampaengpeth, the Minister of Agriculture, Khun Theera Bongsamut, urged farmers to work together in fighting the problem, avoid pesticide abuse and delay planting the next season. He emphasized that farmers must use the right chemicals to fight the pest and he later distributed buprofezin, an insecticide with high planthopper specificity and safe to natural enemies. At the exhibition bottles of insecticides not to be used for hopper control were displayed but I do not think much attention will be paid to them. To mark the opening of the campaign, he lit a model of the planthopper. The Minister later stepped into the rice field to demonstrate insecticide spraying.
The Ministry spent about US$ 1 million to support a total of 28 campaign launch ceremonies conducted in 14 provinces in Central Thailand. In December alone about 300,000 ha had been reported to be heavily damaged by planthoppers. In November the Ministry reduced the rice production forecast of 23.51 million tons by 1.1 million tons (4.7%) valued more than US$ 250 million. As follow ups to the campaign, provincial governments were urged to provide about US$16 million to purchase insecticides for distribution. Many of the commonly used insecticides have adverse effects on biological control services and thus the sudden influx of insecticides might further intensify and/or prolong the problems.
Many rice fields in Khampaengphet and Phisit provinces heavily infested with the rice ragged stunt and rice grassy stunt viruses have been abandoned by farmers. These fields could serve as the virus sources to further spread the diseases. The provinces just south, like Suphan Buri, Ang Thong, Chainat and Sing Buri were at the sowing and seedling stages. With the prevailing winds blowing generally southerly, these rice areas are at risk to virus infection by planthoppers from the north provinces.