A New Combination Fungicide Active Ingredients for Management of Sheath Blight Disease of Paddy

Abstract

Aims: Present study was under taken to determine the field efficacy of a new combination fungicide azoxystrobin 11% + tebuconazole 18.3% w/w SC against sheath blight disease of rice. Study Design: Randomized complete block design (RCBD). Place and Duration of Study: All India Co-ordinated Rice improvement Programme, Agricultural Research Station, Gangavathi (5.4319° N, 76.5315° E), Karnataka, India, during Kharif  2014 and Rabi 2014-15. Methodology: Experiment was designed with seven treatments of three replications each. A new formulations viz., azoxystrobin 11% + tebuconazole 18.3% w/w SC was tested in three dosages (500, 750 & 1000 g/ha) along with other fungicidal treatments such as  azoxystrobin 23% SC at 500 gm/ha, tebuconazole 25.9% EC at 750 g/ha and validamycin 3% L at 2000 g/ha. Bioefficacy was analysed after spraying all the test chemicals thrice at 15 days interval starting from initiation of the disease. Results: The combination fungicide azoxystrobin 11% + tebuconazole 18.3% w/w SC at 1000 ml/ha was found effective against sheath blight disease recording least percent disease index (PDI) of 10.93 during Kharif 2014. Similar result was observed in Rabi 2014-15 where same test fungicide azoxystrobin 11% + tebuconazole 18.3% at 1000 ml/ha recorded the least PDI of 11.60. Compared to azoxystrobin 11% + tebuconazole 18.3%, other test fungicides such as azoxystrobin 23% SC, tebuconazole 25.9% EC and validamycin 3% L recorded highest PDI in both Kharif 2014 and Rabi 2014-15. Significant increases in the grain yield over other treatments (7527 kg/ha) was observed in the plots treated with test chemical azoxystrobin 11% + tebuconazole 18.3% w/w SC at 1000 ml/ha in Kharif 2014 and  5796 kg/ha in Rabi 2014-15. Whereas, other fungicidal treatments recorded the yield range of 5925-6217 kg/ha in Kharif 2014 and 4584 – 5682 kg/ha in Rabi 2014-15. Conclusion: Present investigation  provides the field efficacy of the fungicide mixture Azoxystrobin 11% + Tebuconazole 18.3% w/w SC  at 750-1000 ml/ha for management of sheath blight disease of paddy.