Evaluation of Aromatic Oils as Natural Antifungal Agents Against Plant Pathogens: An In vitro and Pot Condition Study

Abstract

The essential oil of aromatic plants is often possessing antimicrobial features which have an important role in the defense of the plants. Aromatic oil have consist monoterpenes, sesquiterpenes and their oxygenated derivatives, such as alcohol, ketones, acids, phenols, ethers, esters, etc. Different aromatic plants oil viz; Eucalyptus, Basil, lemon grass, Palma Rosa, clove, Citronella, Orange, Neem and, Mint Oil, have been evaluated because it is safe alternative to chemicals and have a limitless ability to synthesize secondary metabolites (eg. phenols, flavones, flavonoids, alkaloids, tannins) which operate as the plant’s defense mechanism against pathogenic microorganisms. These oils have the ability to delay or inhibit the growth of pathogenic fungi including Pythium spp., Rhizoctonia spp. Fusarium spp., Alternaria spp. etc. Highest per cent mycelia growth inhibition of Fusarium oxysporum f.sp. asparagi was recorded in Citrus sinensis at 264 hours after inoculation. Mycilium growth of Pythium aphanidermatum was not recorded              @ 2.0 percent concentration of aromatic oils viz; Cymbopogon nardus, Cymbopogon citratus, Syzigum aromaticum, Mentha piperita, and Azadirachta indica + Mentha piperita and Eucalyptus globulus (00 mm) after 264 hours. The lowest mycelial growth was found in Cymbopogon martini +Cymbopogon citratus 19.75mm.and highest growth observed in control 45.00mm after 264 hours inoculation. In Rhizoctonia solanai maximum percent growth inhibition was found in Syzigum aromaticum 93.84% at 264 hours after inoculation as compare to control. In pot condition, minimum percent mortality of Asparagus racemosus disease caused by Fusarium oxysporum f.sp. asparagi was found in Azadirachta indica +Mentha piperita 17.49%, followed by Cymbopogon nardus 22.49% and Syzigum aromaticum 25.90% at 150 day after transplanting.