Allelopathic had been applied by Molisch at the first time in 1937. He also used this word for chemical interaction of live creatures, and chemical compounds which involve in this process named allelochemical. In order to consider the allelopathic effect of aqueous extracts of annual wormwood (Artemisia annua L.) on germination and early growth of Brassica napus L, an experiment was conducted using a completely randomized design with five treatments (control, 25%, 50%, 75% and 100% concentration of aqueous extracts) and four replications in the laboratory. Results analyzed by SAS software with means subjected to Duncan test at 5% probability level showed that effect of different concentrations of Artemisia annua extract was significant on germination percentage and rate, plumule and radicle lengths and fresh and dried weights of seedlings.
