The fungal pathogen Alternaria sesami was isolated from affected leaves of sesame, collected from experimental filed
of Regional Agriculture Research Station, Kayamkulam. The infected leaves are cut into small pieces (2mm) were
surface sterilized with 1:1000 mercuric chloride (HgCl2) solution for 30 seconds and washed thrice in sterilized double
distilled water to remove the traces of mercury and then transferred to sterilized petri plates (1-2 leaf bits per Petri dish)
containing potato dextrose agar (PDA).The Petri plates were incubated at room temperature (27±1°C) and observed
periodically for the growth of the fungus. Fungal inoculum developed from the infected tissue was transferred to fresh
PDA slants and incubated at 27°±1°C for 12 days. Slants with pure culture were subjected for further studies. A. sesami
cultures were maintained throughout the study period by periodical transfers on sterile petri plates containing PDA
medium under aseptic conditions to keep the culture fresh and viable. Sterile distilled water (10 ml) was added to the
fungal cultures in each petri plate and the conidia were dislodged with a plastic rod to obtain a fungal suspension
containing 108 conidia/ml.