Six crude plant extract namely Lantana, Tridax, Coleus, Lemon grass, Neem and Tulsi were screened for antimicrobial activity against Aspergillus niger, a post-harvest pathogen in grapes fruit. Among aqueous and ethanolic extract of plants maximum inhibition of pathogen was observed in ethanolic extracts. Among the ethanolic extracts, maximum inhibitory concentration of 71.33% was shown by Tulsi (Occimum tenuiflorum) at 5000ppm. GC-MS analysis of ethanolic extract of tulsi showed the bioactive compounds present in it. Further molecular docking analysis of obtained bioactive compounds (ligands) from tulsi against StARkin domain of ergo sterol in fungi showed that eugenol, the bioactive compound present in tulsi is having lowest binding energy of -73.23 kcal/mol with that protein. This showed that eugenol present in tulsi may act as a potential drug target against post harvest fungal pathogen and it may increase the self-life of fruits.