ALLELOPATHIC EFFECTS OF AQUEOUS LEAF EXTRACTS OF TWO INVASIVE PLANTS (CHROMOLAENA ODORATA (L.) R. M. KING 8 H. ROB. AND SPHAGNETICOLA TRILOBATA (L.) PRUSKI) ON SEED GERMINATION OF AMARANTHUS CRUENTUS L

Abstract

The present study was aimed to assess the allelopathic activity of leaf extracts of two invasive plants of Asteraceae family (Chromolaena odorata (L.) R.M. King 8 H. Rob. and Sphagneticola trilobata (L.) Pruski) against the seed germination of red amaranthus (Amaranthus cruentus L.). For the study, 10, 20, 30, and 40 percent solutions of aqueous leaf extracts of both plants were prepared using the shade dried leaves. The experiments were conducted in sterilized petridishes of 9 cm diameter lined by two layers of filter papers. 50 seeds were placed in each of the petridishes. Distilled water was used as control. The numbers of germinated seeds were recorded every day for seven days. By calculating the germination percentage after seven days of experiment, it was clear that the germination percentage decreases with increasing concentrations of leaf extracts. The comparative evaluation of the allelopathy of both extracts showed that the extracts of Chromolaena odorata showed slight increased inhibitory effect on the seed germination than that of Sphagneticola trilobata. It is concluded that the high allelopathic property of both these plants can be responsible for the rapid spreading and successful establishment of these plants and the evaluation, identification and isolation of the allelochemicals in these plants can be a subject for future researches for the production of natural herbicides.