Control of fungal pathogens of Citrus sinensis L. by essential oil

Essential oil, hydrosol extract and hydrosol of Thymus capitatus L. from Algeria were tested for antifungal activity against four phytopathogenic fungi (Aspergillus niger, Aspergillus oryza, Penicillium italicum and Fusarium solani) causing the deterioration of Citrus sinensis fruits. Essential oil and hydrosol extract showed strong in vitro antifungal activity based on the inhibition zone and minimal inhibitory concentration values against the pathogens. Citrus sinensis fruits infected by Penicillium italicum were treated in vivo with essential oil, hydrosol extract and hydrosol. 0.2 μg/mL of Thymus hydrosol was needed for the absence of orange infection and causing 100 % mycelial growth inhibition. This activity can be correlated with chemical composition of extracts which are rich in carvacrol (more than 69 %). Therefore, the preventive and curative effects of T. capitatus essential oil and hydrosol could be exploited as an ideal alternative to synthetic fungicides for using in the treatment of many fungal phytopathogens causing severe destruction to oranges