The effects of essential oils carvacrol and thymol on growth of Penicillium digitatum and P. italicum involved in lemon decay

In this work the antifungal efficacy of thymol, carvacrol and the mixture of both pure essential oils has been proved against Penicillium digitatum and Penicillium italicum, by using in vitro (liquid media, PDA plates and disk growth) and in vivo (lemon) tests. Results indicated that both essential oils were effective in inhibiting fungal growth in all in vitro tests, with the highest efficacy displayed by thymol. In addition, the application of wax with thymol and carvacrol to lemons inoculated with P. digitatum demonstrated the reduction of decay (expressed as percentage of infected fruit surface) in a concentration dependent manner, as well as reduced respiration rate, ethylene production and total acidity losses. Thus, the application of these essential oils together with wax in the citrus packing lines could be considered as good alternatives to reduce the use of synthetic fungicides.

► Thymol and carvacrol inhibit P. digitatum and P. italicum growth on in vitro tests.
► Thymol was the most effective in inhibiting lemon decay caused by P. digitatum.
► These essential oils could be alternatives to the use of synthetic fungicides.