Antifungal Activity of Essential Oil of Some Medicinal Plants against (Dry Rot of Potato) Fusarium oxysporum Schlecht

Abstract

Potato samples were collected from the Kalimati Vegetable Markets of Kathmandu. The fungus, isolated from the infected potato tubers was identified as Fusarium oxysporum Schlecht, which causes dry rot disease of potato tubers in storage. Pathogenecity test was carried out for the conformation of disease. It was confirmed by inoculating the pathogen in to the healthy tubers. Cinnamomum tamala, Nardostachys grandiflora, Eucalyptus citriodora and Cymbopogon citratus were hydro-distilled in laboratory for the extraction of essential oils. The other two essential oils of Mentha arvensis and Acorus calamus were obtained from the HPPCL. Each essential oil was diluted to the different concentrations of 40.0µlml -1 , 20.0µlml -1 , 10.0µlml , 2.5µlml -1 , 1.25µlml -1 and 0.625µlml -1 in 80% acetone. Fungitoxicity was assessed by poisoned food technique. Essential oil of Eucalyptus citriodora showed the highest fungitoxicity (100%) at the concentration of 20.0µlml -1 , while essential oil of Cymbopogon citratus, Nardostachys grandiflora and Acorus calamus showed the highest fungitoxicity (100%) at the concentration of 40.0µlml -1. Similarly, essential oils of Cinnamomum tamala and Mentha arvensis showed the highest fungitoxicity (90.59% and 67.60% respectively) at the concentration of 40.0µlml -1 .

The Minimum Inhibitory Concentration (MIC) of different essential oils was obtained. The MIC of Eucalyptus citriodora was 20.0µlml -1 i.e. the complete inhibition of colony growth of Fusarium oxysporum was seen at 20.0µlml -1 concentration. Similarly, the MIC of Cymbopogon citratus, Nardostachys grandiflora and Acorus calamus was found 40.0µlml -1 against the mycelial growth of Fusarium oxysporum. Thus, comparative antifungal activities of 6 different essential oils were observed against Fusarium oxysporum (the causal agent of dry rot disease of potato tubers in storage). -1 , 5.0µlml -1