2.3. Spore germination assay
A conidial suspension of M. eumusae was prepared by grinding
15-day-old culture with distilled water using a mortar and pestle.
The spore suspension was then filtered through two layers of
cheesecloth and the filtrates containing the spores were adjusted to
4 106 spores ml1 using a haemocytometer. A 100 ml volume of
conidial suspension of the pathogen and 100 ml of various leaf extracts
were placed individually in the concavity glass slides and
mixed thoroughly. The concavity glass slides were kept in separate
Petri dishes on a glass bridge chamber and incubated at 25 C. The
spore suspension of the pathogen in sterile distilled water alone
was served as a control. For each plant extract three replications
were maintained and the experiment was conducted in a completely
randomized block design. The germination of the spores
was observed after 96 h. Conidia were considered to have germinated
if the germ tubes were equal to or longer than the length of
the conidia of the respective pathogen (Khan et al., 2001).
The percent of inhibition was calculated using the formula:
Percent inhibition ¼ C T/C 100, where, C ¼ number of spores
germinated in control (average of 10 microscopic fields); T¼ number
of spores germinated in treated (average of 10 microscopic fields).