R. C. Cabunagan1, I.-R. Choi1 and M. Muhsin2
1International Rice Research Institute, Los Baños, Philippines
2Indonesian Center for Food Crops Research and Development, Bogor, Indonesia
The outbreaks of brown planthoppers (BPH) and the associated virus diseases were previously reported in West Java, Indonesia in March 2010 (See: BPH and virus diseases threatening rice in West Java). A survey conducted on July 21 and 22, 2010 revealed that the problem of BPH and the associated virus was still persisting in West Java province and it has been spreading to other areas of Indonesia. This time the outbreaks of BPH and the associated virus diseases were observed severely affecting rice fields in Central Java province (See also: Trip report-viruses in Indonesia-Choi-Cabunagan).
Klaten regency of Central Java province has about 36,000 ha of rice fields, mostly irrigated. The western part of Klaten was found to be affected by mixed infection with rice tungro spherical virus (RTSV) and rice tungro bacilliform virus (RTBV) transmitted by green leaf hopper (GLH), and rice ragged stunt virus (RRSV) transmitted by BPH (Figure 1 and Table 1). It appeared that the areas have been heavily affected by BPH and virus infection since January 2010 (Table 2). Some farmers in the regency have not been able to harvest their rice crops for three consecutive cropping seasons. During our field survey we saw a farmer spraying etofenprox (trade name “Trebon”) on her rice plants which were already showing symptoms of virus infection (Figure 2). Farmers in this part of Klaten regency seemed to practice very asynchronous rice planting (Figure 3).
Table 1. Estimated area affected by BPH and virus diseases in Klaten regency, Central Java province from January to July 2010
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Table 2. Viruses detected from rice plants collected in 2 locations in Klaten, Central Java
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The eastern part of Klaten was found to be also damaged by BPH, and BPH-transmitted RRSV and RGSV (rice grassy stunt virus). (Figure 4 A, B, and C). According to the extension officer of Klaten, a meeting of the task force for BPH management organized by the local government was being held near the site we visited in eastern Klaten regency (Figure 4D). According to M. Muhsin, concerted efforts for the management of BPH/GLH and associated virus diseases have not been made yet in Indonesia, and the damages from BPH and BPH-transmitted viruses are now possibly spreading to East Java Province aside from West and Central Java.