Abstract
The aim of this paper was to evaluate the effect of essential oils from the Lamiaceae family on the control of Colletotrichum gloeosporioides, Elsinoë ampelina and Phytophthora infestans, as well as to investigate mode of action of the most effective essential oils. Capitalize oils of Lavender (LEO), Basil (BEO), Mint (MEO), Oregano (OEO) and Thyme (TEO) were used at doses of 0, 250, 500, 750 and 1000 µL L(-1). Effects on mycelial growth and spore germination were evaluated to identify the most potent essential oils. Additionally, the action of volatile compounds and the effects of the oils effect on ergosterol content, membrane permeability, and transfer test assessed. OEO and TEO were the most promising, completely inhibiting the development of phytopathogens at nearly all tested doses. Consequently, these two essential oils were selected for further analysis, except 250 µL L(-1)dose, which did not completely inhibit the phytopathogens. Regarding ergosterol content, OEO significantly reduced ergosterol levels in C. gloeosporioides and E. ampelina, while TEO decreased only the ergosterol content of C. gloeosporioides, and did not interfere with the other microorganism. The membrane permeability was also affected by the two essential oils. Only OEO showed no effect on the membrane permeability of E. ampelina. The study also revealed that OEO and TEO exhibited fungicidal effects against C. gloeosporioides and E. ampelina, while showing fungistatic effects against P. infestans. In conclusion, OEO and TEO were found to be the most effective oils in the management of C. gloeosporioides, E. ampelina, and P. infestans. Their distinct mechanisms of action further indicate their potential as potent agents for directly controlling plant diseases.