Essential Oils as Biocides for the Control of Fungal Infections and Devastating Pest (Tuta absoluta) of Tomato (Lycopersicon esculentum Mill.).

Abstract

Thymus capitatus and Tetraclinis articulata essential oils as well their major components (carvacrol and α-pinene) were evaluated for their antifungal and insecticidal activities. Both oils showed good invitro antifungal activity against Fusarium oxysporum, Aspergillus niger, Penicillium sp., Alternaria alternata, and Botrytis cinerea, the fungi causing tomato rot. In vivo results indicate the efficacies of both essential oils and carvacrol of reduce postharvest fungal pathogens, such as B.cinerea and Al.alternata that are responsible of black and gray rot of tomato fruit. Disease incidence of Al.alternata and B.cinerea decreased on average from 55% to 80% with essential oil of Th.capitatus and pure carcvacrol, while Te.articulata essential oil exhibited inhibition of fungal growth of 55% and 25% against Al.alternata and B.cinerea, respectively, with concentration of 0.4μl/l air. The insecticidal activity of Th.capitatus and Te.articulata essential oils exhibited also a good insecticidal activity. At the concentration of 0.2μl/ml air, the oils caused mortality over 80% for all larval stages of Tuta absoluta and 100% mortality for the first-instar after 1.5h only of exposure. α-Pinene presented lower insecticidal and antifungal activities compared to essential oils of Th.capitatus, Te.articulata and pure carvacrol. Thus, these essential oils can be used as a potential source to develop control agents to manage some of the main pests and fungal diseases of tomato crops.