Allelopathic and Antifungal Effects of Saffron (Crocus sativus L.) Aqueous Extract on Germination and Seedling Growth of London rocket (Sisymbrium irio) and Fusarium solani

To evaluate the allelopathic and fungicidal effect of saffron leaf and corm aqueous extracts on the germination and growth characteristics of London rocket (Sisymbrium irio) and Fusarium solani, independent experiments were conducted as factorial arrangement based on the completely randomized design with four replications at the Faculty of Agriculture of Birjand University in 2022. Treatments to test the inhibitory effect of saffron extract on London rocket seed germination characteristics including two types of saffron organs (leaf and corm) and seven extract concentrations (0, 0.25, 0.5, 1, 1.5, 2, and 4 w/v %). Experimental treatments to investigate the inhibitory effect of saffron extract on the growth of Fusarium solani fungus including two types of saffron organs (leaf and corm) and seven extract concentrations (0, 1, 0.5, 25. 0, 0.125, 0.625, and 0.0312 w/v %). The results showed that the type of extract has an effect on the germination percentage, germination rate, mean germination time, length and fresh and dry weight of radicle, the length, fresh and dry weight of the plumule, seedling dry weight, and the seedling vigor of London rocket were significant, and the corm extract had more negative effects compared to the leaf extract. As the extract concentration increased, its inhibitory effect also increased. The extract concentration of 4% significantly reduced the radicle length and fresh and dry weight, the plumule length and fresh and dry weight, seedling dry weight, and seedling vigor of London rocket compared to the control. The results of the interaction showed that the lowest percentage of germination, germination rate, radicle length and fresh and dry weight, plumule fresh and dry weight and seedling dry weight of london rocket were observed at the concentration of 4 % corm extract. The results of the interaction effect of extract type and extract concentrations on Fusarium solani colony diameter showed that all the concentrations of corm extract inhibited the growth of Fusarium solani in all four stages of sampling. In leaf extract, concentrations of 0.125, 0.25, 0.5 and 1% completely inhibited the growth of Fusarium solani in all four stages of sampling. Finally, the results of these experiments showed that the effect of inhibiting the germination and growth of london rocket as well as the antifungal effect is greater in saffron corm extract than the leaf extract. Therefore, considering the results of this research and conducting more research in the field of allelopathic and fungicidal effects of saffron organ extracts, we can proceed to produce natural herbicides and fungicides.