Present study was formulated to find out the phytotoxic effects of different concentrations of water, ethyl acetate, petroleum ether and methanol extracts of Portulaca oleracea seeds on germination, germination index and seedlings growth of Cichorium endivia, Lactuca sativa Echinochoa crus-galli, and Brassica tournefortii. Also the total phenolics and flavonoids were determined. Results indicated that the responses of allelopathic effects were depends on extract type and concentration. Furthermore, the higher concentration had a stronger inhibitory effect on seed germination whereas in some cases the lower concentration showed a stimulatory effect. Hence, it is suggested that Portulaca oleracea seeds has strong allelopathic potential and might be use for biological control of weeds.
