Allelopathic effects of Hemistepta lyrata on the germination and growth of wheat, sorghum, cucumber, rape, and radish seeds

Abstract

The allelopathic effects of a water extract from Hemistepta lyrata were tested on the seeds of selected crops in Petri dishes. The results showed that the extract strongly inhibited the germination and seedling growth of wheat (Triticum aestivum), rape (Brassica campestris), and radish (Raphanus sativus), but only slightly inhibited those of sorghum (Sorghum vulgare) and cucumber (Cucumis sativus). The extract stimulated the growth of roots and hypocotyls at lower concentrations, while it inhibited their growth at higher concentrations. The malondialdehyde (MDA) content of cucumber and radish increased after treatment with the extract. These results indicated that the MDA concentration in plants is one important aspect of the allelopathic effects of H. lyrata.