In vitro evaluation of fungicides and bio-agents against Drechslera tetramera, Bipolaris sacchari, Nigrospora sphaerica and Alternaria alternata causal agent of leaf spot of medicinal and aromatic grasses

Abstract

India is a global leader in essential oil steam distilled from aromatic crops. Most of the species of Cymbopogon. e. C. winter ianus Jowitt, C. flexuosus (Nees) Wats. and C. martinii (Roxb.) Wats. have been cultivated for a long time for their essential oils. Few fungal pathogens like Drechslera tetramera, Bipolaris sacchari, Nigrospora sphaerica and Alternaria alternata are known to attack these grasses causing leaf spot which results into substantial yield losses. The present investigation was carried out to test the efficacy of fungicides and bio-agents In Vitro. Among fungicides tested, the highest (100%) mycelial inhibition of Drechslera tetramera, Bipolaris sacchari, Nigrospora sphaerica and Alternaria alternata were recorded in Propiconazole (0.1%) and Propiconazole + Difenoconazole (0.1%). The results of dual culture technique revealed that maximum growth inhibition of Drechslera tetramera (61.60%), Bipolaris sacchari (62.00%), Nigrospora sphaerica (67.88%) and Alternaria alternata (55.00%) was observed with Trichoderma viride followed by Pseudomonas fluorescens and Bacillus subtilis.