Brown planthopper (BPH) outbreak in Thanjavur District, Tamil Nadu
1988
Natarajan, K. | Venugopal, M.S. | Chelliah, S. (Tamil Nadu Rice Research Inst., Aduthurai, Tamil Nadu (India))
During the Jun-Sep 1987 drought due to failure of the monsoon, a BPH [brown planthopper] outbreak in Sivapurani Kondosamudram, and Kurichi villages of Kumbakonam division, Thanjavur District, caused typical hopperburn symptoms on IR50. Approximately 100 ha were affected. Farmers applied double the recommended N as basal fertilizer. Because the insecticides used were not directed toward the base of the plants, control was inadequate. Furthermore, the farmers sprayed quinalphos, a resurgence-causing insecticide which aggravated the pest population. Unsprayed fields recorded 56 hoppers/hill; phosphamidon-sprayed fields had 8 hoppers/hill. Where quinalphos was sprayed, populations exceeded 250 hoppers/hill. Populations of natural enemies like mirid bug, wolf spider and coccinellid beetles were higher in unsprayed fields.
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