## 5 Conclusions  
In conclusion, the data described in this study demonstrate that EOs of cinnamon bark, palmarosa, and verbena were efficient at inhibiting _F. graminearum_ growth as decreased mycelium growth, and alterations in morphological structures and ergosterol quantification were observed. The current study demonstrated that all three tested EOs effectively suppressed the development of _F. graminearum_ in concentrations of 5 and 10%. The in vitro fungistatic effect was dependent on the tested EOs as well as on its concentration. Among them, cinnamon and verbena EOs displayed the strongest in vitro antifungal activity against the tested fungi. Furthermore, the tested natural plant compounds proved to be effective in mycotoxin production-inhibition, and may be an alternative to synthetic chemical agents. The high importance of the tested EOs' antimycotoxigenic properties is related to the damage that these _Fusarium_ species mycotoxins cause to human and animal health. Recently developed fungicides often demonstrate systemic or curative properties aimed at effective disease control, but have limited applications at low rates. Furthermore, the emerging problem of fungicide-resistant microorganisms urges researchers to develop new biocontrol agents or fungicides possessing novel action mechanisms. Therefore,cinnamon bark, palmarosa leaves, and verbena leaf and flower EOs were proved to be potential biological agents for the control of _F. graminearum_ diseases in crops and ZEA and DON mycotoxin production. Future in vitro tests are mandatory, including tests on different _Fusarium_ species and mycotoxins, as well as concerning EO composition, in order to evaluate the broad spectrum of fungistatic activity as well as the inhibition of varied mycotoxin production. Additional advanced greenhouses and field in vivo research are needed in order to determine the potential usefulness of palmarosa, verbena, and cinnamon bark EOs in fungal control programs.  
The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/app12010473/s1](https://www.mdpi.com/article/10.3390/app12010473/s1)]([https://www.mdpi.com/article/10.3390/app12010473/s1](https://www.mdpi.com/article/10.3390/app12010473/s1)). Figure S1. Morphology of _F. graminearum_ hyphae hyphae under light microscope (magnification \(\times\) 400) treated with verteban EO: (a) Control; (b) EO concentration 0.1%; (c) EO concentration 1.0%; (d) EO concentration 5.0%; (e) EO concentration 10.0%; Figure S2. Morphology of _F. graminearum_ hyphae under optical microscope (magnification \(\times\) 400): untreated: (a) control, stained with FDPA; trained with FDPA; trained with FDPA; trained with FDPA; trained with FDPA; trained with FDPA; concentration: (d) 0.1%; (f) 1.0%; (h) 5.0%; (j) 10.0%; Figure S3. Morphology of _F. graminearum_ hyphae under optical microscope (magnification \(\times\) 400): untreated: (a) control, stained with cFDA; (b) control, stained with PI; treated with verteban EO: stained with cFDA; EO concentration: (c) 0.1%; (e) 1.0%; (g) 5.0%; (j) 10.0%; stained with PI, EO concentration: (d) 0.1%; (f) 1.0%; (h) 5.0%; (j) 10.0%.  
Conceptualization, D.G., K.M. and K.J.; methodology, D.G, K.M., K.J. and A.W.; validation, K.J. and A.W.; formal analysis, K.M., D.G., R.G. and R.K.; investigation, D.G., K.M., K.J., P.A.U., R.G., A.W. and R.K.; resources, D.G., K.M., K.J. and R.G.; data curation, K.J. and A.W.; writing--original draft preparation, D.G., K.M., K.J. and A.W.; writing--review and editing, D.G., K.M. and K.J.; visualization, D.G., K.J. and K.M.; supervision, D.G.; project administration, K.M. All authors have read and agreed to the published version of the manuscript.  
This research was funded by Polish National Science Centre, grant number 2018/31/B/NZ9/03485.  
Not applicable.  
The authors declare no conflict of interest.