Due to their solubility in agar and ability to diffuse
from paper discs, the disc diffusion method was
used for screening the antimicrobial activity of the
essential oils (Janssen et al., 1987). As shown in
Table 1, the lowest concentration of citronella, holy
basil and sweet basil oils showing an inhibition zone
were 1.00% v/v, whereas that of lemongrass and
kaffir lime oils was found at 0.25% v/v. However,