Antifungal activity of plant oils against major seed-borne fungi of rice

Abstract

A total of four fungal genera were isolated and identified from rice as Curvularia lunata,Fusarium moniliforme, Helminthosporium oryzae and Sarocladium oryzae. Among them, the most predominant one was H. oryzae. This was followed by S. oryzae and F. moniliforme. Least incidence was observed with C. lunata with the variety ADT 45 and White ponni. Six essential oils viz., Lemongrass (Cymbopogon citratus), Palmarosa (Cymbopogon martinii), Citronella (Cymbopogon nardus), Eucalyptus (Eucalyptus globulus), Geranium (Pelargonium graveolens) and Tulasi (Ocimum sanctum) extracted by hydro distillation process were screened against four major seed borne pathogens of rice. In vitro evaluation of six essential oils at 0.1 per cent by poisoned food
technique showed varied fungicidal properties against C. lunata, F. moniliforme, H. oryzae and S. oryzae. Among them, C. citratus, C. martinii and P. graveolens oils were found to be more effective and caused complete mycelial growth inhibition of pathogen even at 0.1 per cent concentration. However, oils of C. nardus, E. globulus and O. sanctum were not resulted in complete inhibition of mycelial growth of C. lunata, F. moniliforme, H. oryzae and S. oryzae at 0.1 per cent concentration.