Phytotoxic activity of Tecomella undulata (Sm.) Seem extracts on some ornamental plants

Abstract

Tecomella undulata is an ecologically and economically important tree in arid areas of southwestern Asia. It has important ornamental and medicinal uses. In this study, aqueous extracts from roots, leaves, inner stem barks and flowers of T. undulata were studied for their allelopathic effects on seed germination and early seedling growth of four important monocotyledonous and dicotyledonous ornamental plants. The flower and root extracts of T. undulata significantly (P<0.05) inhibited germination of tall fescue (Festuca arundinacea Schreb.) and perennial ryegrass (Lolium perenne L.) seeds, but leaf and inner stem bark extracts had no significant effects on either of these turf grasses. The allelopathic inhibition was greater for root extracts than flower extracts, and increased with higher root extract concentrations. The germination of cocks comb (Celosia argentea) and rose moss (Portulaca grandiflora) seeds were not inhibited by the application of T. undulata extracts. The results showed that the extracts of T. undulata have allelopathic effects on seed germination and seedling growth of the two monocotyledonous plants tested but not with the two dicotyledonous plants tested. T. undulata extracts may have selective potential for natural weed control.