A village planting hybrid rice, located in Barangay Jasaan in Sta. Cruz, Laguna, just a few kilometers from the International Rice Research Institute, recently had its first experience of outbreak of rice planthoppers. There are more than 60 hectares of rice farms in the village, mostly planted with the inbred variety PSBRc18.
Some fields were planted with the hybrid rice, SL-7. Both varieties have very high populations of planthoppers, of about 500-1,000 individuals per hill.
Despite the high hopper population in PSBRc18, there is only a slight yellowing on the leaves of the plants. Patches of hopperburn areas (Picture 1) were observed in the fields planted to hybrid rice SL-7 at the booting to early flowering stages.
Mr. Alfredo Baltazar, the farmer of 1.3 hectares of hybrid rice field with hopperburn, said that it is his first time to plant SL-7 in his farm. In the previous two seasons, he planted the hybrid rice Mestizo 1 and was delighted to harvest around 180 cavans (or about 9.0 tons) per hectare.
Optimistic about getting a good harvest with hybrids, he planted SL-7 this season which he sourced from a nearby seed company, SL Agritech. He was very disappointed to see that his crop has been severely infested with hoppers despite spraying more than 5 times for pest control.
The Regional Crop Protection Center IV of the Department of Agriculture, in cooperation with the Laguna Provincial Agricultural Office (PAO), reported that the field was sprayed at 3 weeks after transplanting with chlorpyrifos insecticide.
Subsequent sprays of the same chemical were done five more times at weekly intervals. The initial sprayings were targeted at leaf-feeding insects but the later sprays were for planthoppers. The other insecticide used was a mixture of chlorpyrifos and BPMC.
In addition to this farm, rice fields in the adjacent Barangay (Malinao) in the same town are also heavily infested with hoppers. Both winged and non-winged forms were observed on the rice plants. Some PSBRc18 plants showed yellowing and stunting in