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A. RAJESH*, T. MANOHARAN AND G. RANJITHA
Department of Agricultural Entomology, TNAU, Coimbatore – 641 003, T.N.
Supervised field experiments were conducted in rice for two seasons to evaluate the bioefficacy of carbosulfan 25 EC (New Source) as foliar spray against green leafhoppers (GLH) (Nephotettix virescens Distant. and Nephotettix nigropictus Stal.) in rice ecosystem. Application of carbosulfan 25 EC (NS) at 300, 250, 200 and 150 g a.i. ha-1 recorded 83.90, 79.49, 62.94, 55.43 and 80.95, 76.49, 54.44, 41.97 per cent reduction of GLH population during first and second season, whereas carbosulfan 25 EC (Existing Source) 250 g a.i. ha-1 recorded 77.60 and 75.37 per cent reduction of GLH population during first and second season, respectively. The standard check chlorpyrifos 20 EC at 375 g a.i. ha-1 and at 250 g a.i. ha-1 recorded 61.29, 53,54 and 51.69, 40.38 per cent reduction of GLH population during first and second season, respectively. Carbosulfan 25 EC (NS) recorded a significant reduction in the GLH population and the effect was remarkable in both the seasons. Carbosulfan 25 EC (NS) at 300 g a.i. ha-1 was more effective in reducing GLH population than the lower doses 150, 200 and 250 g a.i. ha-1. Based on the per cent reduction in mean GLH population over untreated check after two sprays in both seasons, the order of efficacy of different treatments is as follows: carbosulfan 25 EC (NS) 300 g a.i. ha-1, carbosulfan 25 EC (NS) 250 g a.i. ha-1, carbosulfan 25 EC (ES) 250 g a.i. ha-1, carbosulfan 25 EC (NS) 200 g a.i. ha-1, chlorpyrifos 20 EC 375 g a.i. ha-1, carbosulfan 25 EC (NS) 150 g a.i. ha-1 and
chlorpyrifos 20 EC 250 g a.i. ha-1.
Carbosulfan 25 EC (NS), Chlorpyrifos, Nephotettix nigropictus, Nephotettix virescens.