Investigation of in vitro and in vivo antifungal activities of different plant essential oils against postharvest apple rot diseases - Colletotrichum gloeosporioides, Botrytis cinerea and Penicillium expansum

The essential oils (EOs) extracted from sage (Salvia officinalis), rosemary (Rosmarinus officinalis), Oregano (Origanum vulgare), eucalyptus sp. and fennel (Foeniculum vulgare) were tested for their antifungal capacities against Penicillium (P.) expansum, Colletotrichum (C.) gloeosporioides and Botrytis (B.) cinerea in vitro and in vivo using golden delicious apples. The main components found in the essential oils of rosemary, sage, fennel, eucalyptus and Oregano were camphor (26.25 %), α-thujone (14.95 %) along with 1.8-cineol (13.40 %), trans anethole (80.73 %), cymene (24.90 %) and carvacrol (81.25 %) respectively. The percentage of mycelial growth inhibition was determined using fumigation bioassay and contact bioassay techniques. Oregano EO was found to be the most effective essential oil against fungi species in in vitro and in vivo trials. The descending order of inhibition power of other EOs was noted as eucalyptus, fennel, sage and rosemary. Oregano EO did not stop the fungal growth completely at selected concentrations. However, it was able to limit the growth of fungi (fungistatic) in in vitro bioassays from approximately 80 to 15 mm, from 19 to 4 mm and from 50 to 9 mm in diameter for B. cinerea, P. expansum and C. gloeosporioides respectively.