Antisporulation activity can be assessed by using scanning electron microscopy (Inouye et al, 1998), while effects on conidium germination can be evaluated by exposing the conidia to the test substance and subsequently counting the number of conidia with germ tubes equal to 1-1.5 times conidium length (Antonov et al, 1997). Additional observations of germinated conidia over a set period will also allow evaluation of the effect of the plant extract on germ tube growth.
All the methods have their own advantages and disadvantages as describe above in testing of antibacterial activity. In addition to these Inouye et al. (2001) showed that the inclusion of Tween-80 resulted in weaker bioactivity in agar dilution assays and the size of the original fungal inoculum had a significant effect with larger inoculums being more resistant to antifungal effects. Shahi et al. (1999) in their study of the antifungal activity of essential oils found that the antifungal response was altered by modifying the pH of the fungal growth media. As the media pH become more alkaline the eucalyptus essential oils had a greater inhibitory effect on the fungi (Trichophyton spp., Microsporum spp, and Epidermophyton spp.).