# The Fungicidal Effect of Essential Oils of Fennel and Hops against Fusarium Disease of Pea
## 3 Results and discussion  
### Determination of Antifungal Activity In Vitro  
The antifungal activity of EOs has been investigated in numerous _in vitro_ studies [32; 40; 49]. In the present study, _in vitro_ analysis of the linear growth of the fungal species studied showed differences in the antifungal potential of the essential oils investigated. Mycelial growth of all pathogens studied was significantly inhibited only by the two highest concentrations of FEO and HEO (1000 ppm and 2000 ppm) (Figures S1 and S2). When applied at the highest concentration (2000 ppm), HEO inhibited the growth of fungal pathogens by 60.7-91.5% and FEO by 79.31-100% (Tables 1 and 2). Tebuconazole inhibited mycelial growth of all species tested in the trial. _Fusarium poae_ (91.5% growth inhibition), followed by _F. culmorum_ (86.6%) and _B. cinerea_ (81.3%) were the most susceptible to HEO. _Fusarium tricinctum_ (76.2%), _F. equiseti_ (76.0%), _F. sporotrichoides_ (73.0%) and _F. avenaceum_ (71.7%) were also effectively inhibited by HEO. Hop essential oil was least effective against _C. destructans, F. solani_ and _F. oxysporum_, whose mycelial growth was reduced by 65.8%, 61.9% and 60.7%, respectively, at the highest concentration of HEO (2000 ppm) (Table 2). The present _in vitro_ study showed that higher concentrations of FEO and HEO inhibited mycelial growth of all fungal species studied. The percentage of mycelial growth inhibition (MGI) varied between the essential oils and pathogens tested. Similar observations were made by [PERSON] et al. [21] who analysed the fungistatic activity of 12 essential oils, including FEO, against _F. oxysporum_ and _B. cinerea_. The cited authors reported significant differences in MGI between the essential oils studied and their concentrations. In 8-day-old cultures of _F. oxysporum_, mycelial growth was not significantly inhibited by the four lowest concentrations of FEO (3, 5, 7, 9 and 15 \(\mu\)L/10 mL PDA). _Fusarium solani_ was one of the least susceptible pathogens, with 79.31% of its growth inhibited by both essential oils. The other _Fusarium_ pathogens were more sensitive to FEO, which reduced fungal activity by 83.8% in _F. avenacean_, 89.3% in _C. destructans_, 91.2% in _F. equiseti_ and 95.7% in _F. tricticum_. The antifungal activity of FEO against _F. oxysporum_ and _F. sporotrichoides_ was very high at 99%. Similar to HEO, FEO was most effective against _B. cinerea_, _F. culmorum_ and _F. poae_, whose growth was completely (100%) suppressed (Table 1). The study by [PERSON] et al. [21] showed that only the higher concentrations of FEO strongly (15, 30, 50 \(\mu\)L/10 mL) or completely (70 \(\mu\)L/10 mL) inhibited the growth of _F. oxysporum_. Mycelial growth of _B. cinerea_ was not affected by FEO concentrations of 3 to 30 \(\mu\)L/10 mL, and a significant reduction was only observed at FEO concentrations of 50 and 70 \(\mu\)L/10 mL. The highest FEO concentration (70 \(\mu\)L/10 mL) inhibited _B. cinerea_ growth by 100%. [PERSON] et al. [25] demonstrated _in vitro_ that FEO is an effective antifungal agent against _F. culmorum_ and _F. graminearum_. The opposite results were obtained by [PERSON] et al. [49], who investigated the antifungal properties of dill seed essential oil at a concentration of 10 ppm. The analysed