Fungicidal Management of False Smut Disease in Rice Caused by Ustilaginoidea virens

Abstract

False smut of rice caused by the fungus Ustilaginoidea virens has been recorded, in recent years, in the all rice growing areas of State Uttar Pradesh, India. Recommended fungicides are not yet available for chemically controlling the disease. Therefore, uses of unregistered fungicides are common by the farmers, for the management of the disease. The present study, was undertaken to identify effectiveness of fungicides to control false smut of rice. Four systemic fungicides (Propiconazole 25% EC @ 1.0 ml/L, Azoxystrobin 18.2% + Difenconazole 11.4% SC @ 0.5 g + 0.5 ml/L, Azoxystrobin 18.2% @ 1.0 g/L and Tebuconazole 250 EC @ 1.0 ml/L) were evaluated as foliar application in the naturally induced diseased rice, at five different locations in district Siddharthnagar, Uttar Pradesh. Fungicide was applied twice, first at panicle initiation and second at early flowering stage. All the fungicides applied were found effective in controlling the disease. As compared to the untreated (only water application), the fungicide ‘Propiconazole 25% EC’ reduced the maximum disease severity by 93.57%, followed by ‘Azoxystrobin 18.2% + Difenconazole 11.4% SC @ 0.5 g + 0.5 ml/L’, Fungicide Tebuconazole 250 EC @ 1.0 ml/L was found least effective in controlling the disease. It is concluded that more multi-location experiments will be required to reach a decisive conclusion on foliar chemical options for controlling rice false smut disease in eastern parts of Uttar Pradesh.