Use of essential oil as botanical-pesticide against post harvest spoilage in Malus pumilo fruit

Abstract

During antifungal screening of the essentialoils of some angiospermic plants, oil ofCymbopogon flexuosus showed potentbioactivity against dominant post harvestfungal pathogens. The minimum bioactiveconcentrations with fungicidal action of theoil was found to be 0.2 µl ml−1 for Alternaria alternata, 0.4 µlml−1 for Aspergillus flavus, A.fumigatus, A. niger, A. parasiticus,Cladosporium cladosporioides, Colletotrichumcapsici, C. falcatum, Curvularia lunata,Fusarium cerealis, F. culmorum, F. oxysporum,F. udum, Gloeosporium fructigenum, Penicilliumexpansum, P. italicum, P. implicatum, P. digitatum,P. minio-luteum, P. variable,and 0.5 µl ml−1 forBotrytis cinerea, Helminthosporium oryzae, H.maydis, Phoma violacea, Rhizopus nigricans.The oil exhibited potency against heavy doses(30 mycelial disc, each of 5 mm in diameter) ofinoculum at 1.0 µl ml−1 concentrations.The bioactivity of the oil was thermostable upto 100°C and lasted up to 48 months.The oil preparation did not exhibit anyphytotoxic effect on the fruit skins ofMalus pumilo up to 50 µlml−1 concentrations. In vivo trials of theoil as a fungicidal spray on Malus pumilofor checking the rotting of fruits, it showedthat 20 µl ml−1 concentration controls100% infection by pre-inoculation treatment,while in post-inoculation treatment, 30 µlml−1 concentration of fungicidal spraywas required for the 100% control of rotting.The fungicidal spray was found to be costeffective (INR 15/l), has long shelf life (48month) and was devoid of any adverse effects.Therefore, it can be used as a potential sourceof sustainable eco-friendly botanicalpesticide, after successfulcompletion of wide range trials.