An Investigation into the Effect of Allelopathic Potential of Achillea wilhelmsii on Germination and Growth of Hirshfeldia incana and Hordeum glaucum

Weeds pose a serious threat to farmers. Using allopathic properties of the plants, especially those of the medicinal plants, has an important role in controlling weeds. This study was conducted to examine the allelopathic potential of Achillea wilhelmsii in germination of Hirshfeldia incana and Hordeum glaucum. A factorial experiment was conducted, adopting a completely randomized design with three replicates in both libratory and pot cultivation. Organ extracts (flower, leaf and root) of Achillea wilhelmsii in four concentrations were used, namely: 1, 2 and 5%. In addition, distilled water was used as a control. The result showed that the greatest percentages of the germination of Hordeum glaucum and Hirshfeldia incana were in the distilled water, which were 100 and 91%, respectively and that their germination reached zero percent under extraction of leaf and flower with a concentration of 5%. The concentration higher than 2% of the extraction of Achillea wilhelmsii significantly decreased germination, length of radicle and aerial part, fresh and dry weight of shoot and root, leaf area index and amount of chlorophyll in Hordeum glaucum and Hirshfeldia incana, in contrast with distilled water. The results showed that leaf and flower extraction of Achillea wilhelmsii had allopathic effects. In addition, it had impacts on germination and growth of the seeds of Hordeum glaucum and Hirshfeldia incana, which could be used in the production of natural herbicides.