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Abstract

Bipolaris oryzae, the causal agent of rice brown spot, is a major constraint to rice production, necessitating effective eco-friendly and chemical management options. A series of in vitro studies were conducted to eval uate the essential oils, fungicides and botanical extracts against B. oryzae using the poisoned food technique. Among essential oils, clove oil showed the highest inhibition (75.6%) at 500 ppm concentration, followed by lemon grass oil (64.9%). Among fungicides, azoxystrobin 23% SC was most effective, recording 67.3% mean inhibition and 88.9% inhibition at 500 ppm, while difenconazole 25% EC and propiconazole 25% EC showed 84.4% and 81.5% inhibition, respectively. Fifteen botanical extracts were tested at 1-3% concentra tions, of which soap nut extract was most effective, causing 61-86% inhibition, followed by garlic, datura and ocimum whereas turmeric and ginger were ineffective up to 3% concentration. The study highlights clove and lemongrass oils, soapnut extract and effective fungicides (azoxystrobin, difenconazole and propiconazole) as promising options for managing rice brown spot.