Control of Penicillium expansum and Botrytis cinerea on pear with Thymus kotschyanus, Ocimum basilicum and Rosmarinus officinalis essential oils

The aim of this study was to test the possibility of the use of Thymus kotschyanus,Ocimum basilicum and Rosmarinus officinalis essential oils to reduce postharvest losses induced by Botrytis cinerea and Penicillium expansum in pear fruits. In this study, the antifungal activity of essential oils under in vitro condition were assayed by poison food medium method (0, 100, 200, 300, 400 and 500 μL/L) and under in vivo condition by spraying different essential oil concentrations (0, 100, 300 and 500 μL/L) on inoculated pear fruits. Results of the present study showed that T. kotschyanus had the highest antifungal activity under in vitro condition and completely inhibited fungal growth at concentrations above 200 μL/L. Results of in vivo studies showed that T. kotschyanus oil decreased the disease severity and number of infected pear fruits inoculated with B. cinerea and P. expansum. Measurement of quality sensors of pear fruits showed that essential oil treatment increased the taste of fruits. T. kotschyanus oil also reduced and in the contrast O. basilicum oil increased the firmness of oil-treated fruits. Results of this study showed that T. kotschyanus had good inhibitory effect on growth of phytopathogenic fungi and may be used as a new tool for preservation and extension of shelf-life of pear fruits.   Key words: Essential oil, pear, Thymus kotschyanus, Ocimum basilicum, Rosmarinus officinalis, antifungal.