Antifeedant effect of Brassica nigra seeds against cotton leafworm Spodoptera littoralis and its potential antibacterial activity

Water extract of mustard seeds (Brassica nigra L.) at 40, 20 and 10% concentrations were applied to evaluate the bioactivity of mustard seed extract against the 4th instar larvae of cotton leafworm Spodoptera littoralis. Increasing concentration of mustard extracts exhibited anti-feedant activity. Antibacterial potential of mustard seeds was determined using the disc diffusion test against 10 bacterial strains; Aqueous and acetone extracts showed very weak or no antibacterial activity ranging from 6.0 to 7.75 mm zone of inhibition (ZI), 6.0 mm is the diameter of the blank disc and means no activity; The methanol extract showed varied degrees of weak antibacterial activity (ranging from 6.5 to 8.75 mm ZI). B. nigra could be a good source of insect antifeedant agents.