Director, Chainat Seed Center
Rice Department, Chainat, Thailand
The brown planthopper has become a serious threat in rice production in Thailand’s central plains. What had been reported from Suphan Buri earlier in Ricehoppers.net (https://ricehoppers.net/2009/08/10/hopperburn-in-thailand%e2%80%99s-rice-bowl/) seemed to be have affected a much wider area. The Thai Ministry of Agriculture on 1 September 2009, reported that as much as 1,072,300 rai or 171,568 ha.(1 rai=1600sq.m) in 12 provinces; Angthong, Suphanburi, Singburi, Uthaithani ,Nakhonsawan, Kamphaengphet, Saraburi, Lopburi, Khonkaen, Chainat, Phichit and Maehongson were seriously affected. Hopperburn spots were also observed in provinces Mahasarakham, Chaiyaphum, Nan, Phrae, Nakhonratchasima and Chonburi. Some of the factors contributing to these outbreaks in Central Thailand were the higher temperatures in between June and August, the longer drought period, and agronomic practices such as intensive rice cropping (3 crops a year or 5 crops in 2 years), high seed rate (> 180 kg./ha.) used, continuous planting (> 6 years) of a few varieties like Pathum Tani 1, variety said to have BPH resistance, over a large area, and the excessive use of insecticides. The lack of genetic biodiversity and continuous destruction of ecosystem services by the excessive use of pesticides may have rendered rice systems in the Central Plains, vulnerable to planthopper invasions that had led to the outbreaks.
The Rice Department under the leadership of the Director General, Khun Prasert Gosalvitra, launched a 2-day information campaign on 3 September, 2009 to educate farmers on the reasons why the outbreaks have occurred and to take the necessary action, like reducing insecticide use. The campaign will involve training of at least 2,000 farmers a day in the most badly affected areas in Suphan Buri and Nakhonsawan. Rice Department officials fear that if rice fields in the Central Plains continue to be vulnerable in the months of November and December, a much larger outbreak would be likely.
Meanwhile, the Rice Department is participating in the Rice Planthopper Project supported by IRRI and ADB in training workshops on pest monitoring, ecological engineering techniques, toxicological techniques and farmer surveys, to monitor the situation’s development and to explore for more sustainable ways to reduce vulnerability of rice crops to pest outbreaks.