In vitro efficacy of bio-agents and essential oils against Alternaria chlamydospora, causing leaf spot disease of okra

Abstract

Okra leaf spot disease incited by Alternaria chlamydospora is serious disease in India. Considering the economic importance and destructive nature of the disease, the present in vitro studies were undertaken to evaluate in vitro efficacy of various bio-agents and essential oils against A. chlamydospora by using Dual Culture Technique and Poisoned food technique, respectively. The results of the present studies revealed that, among the bio-agents tested T. longibrachiatum was found most effective which recorded least mycelial growth (28.16 mm) and highest mycelial growth inhibition (68.71%), followed by P. fluorescens (29.16 mm and 67.60%). However, among the tested essential oils, complete mycelial growth inhibition of the test pathogen was recorded by Garlic oil and Clove oil at 0.1% and 0.2% concentration respectively, followed by the essential oils of Sesame (57.12%).