2.10 Contact antifungal activity of geraniol in vitro
The contact antifungal activity of geraniol againstNeopestalotiopsis sp. and C. gloeosporioides was determined following a procedure described in a previous study (Jiang et al., 2020). The median inhibitory concentration (MIC50) of geraniol was determined using a serial two-fold dilution method. Based on preliminary experiments, the stock solution was serially diluted in 30 mL of PDA medium at 45–50°C at different concentrations (1 µl/mL, 0.5 µl/mL, 0.25 µl/mL, 0.125 µl/mL, and 0.0625 µl/mL) to evaluate inhibitory activity againstNeopestalotiopsissp. and C. gloeosporioides. The negative control received the same quantity of acetone mixed with PDA. Ten mL of toxic medium was poured onto aseptic 9-cm plastic Petri dishes. A 5-mm diameter fungal disc of Neopestalotiopsis sp. and C. gloeosporioides was immediately inoculated in the center of each PDA plate, and plates were incubated in the dark at 25°C. After 5 days, colony growth diameter (mm) was measured using digital calipers. Each test was repeated three times.