With the aim of examining the allelopathic effects of saffron (Crocus sativus), Chenopodium album and Echinochloa crus-galli were selected for this study. The experiment was carried out in different levels using aqueous extract of different organs (leaf, corm and a combination of leaf and corm) with different concentrations of the extracts (0, 1, 2.5, 5, 10 and 20%). The results showed that seed germination of both weeds was significantly affected by the organs and concentration of saffron extracts. The highest germination rate of C. album was 2.38 seeds per day in the application of corms extract and the lowest germination rate was 2.12 seeds per day in the application of combination of leaf and corm extract. The highest seed vigor index of C. album was 12 in the application of leaf extract and the lowest was 9 in the application of leaf and corm extracts. In addition, the C. album application of the highest concentration of the extract (20%) led to the lowest weight of root, stem, seedlings, germination percentage, germination rate, seed vigor index, and number of normal seeds. In E. crus-galli, the increase in the concentration of the extract from 0 to 20% enhanced the mean germination time from 3.4 in control sample to 4.1 days with 20% extract concentration. All the applied extracts obtained from different saffron organs caused a significant reduction in germination traits in both species of weeds. Meanwhile the extracts of leaf and corm exerted the highest effects. Generally, the results showed that the application of 20% extract obtained from the combination of leaf and corm tissue provided the highest growth inhibition and lowest germination rate in both weeds.

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