Abstract
The allelopathic potential of different concentrations of aqueous leaf and flower extracts of Calotropis procera and Morettia philaeana were investigated in laboratory experiments for germination and seedlings growth of Triticum aestivum (wheat), Raphanus sativus (radish) and Brassica napus (canola). The germination of wheat and radish was delayed and its percentage was reduced significantly after treatment with leaves extracts of C. procera and M. philaeana. Shoot and root length was significantly reduced after treatment. The reduction of seed germination percentage and shoot and root length was proportional to the concentration of the extracts used. Flower extract of C. procera delayed the germination in wheat and reduced significantly the root and shoot lengths, where as the extract delayed and reduced significantly the germination percentage and reduced significantly shoot length in canola. Distinct stress on germinated seeds appeared as proline content increased significantly in wheat plants after treatment with C. procera or M. philaeana extracts particularly at higher concentration of the extracts. Morettia philaeana aqueous extract was stronger than that of C. procera on wheat and radish. (C) 2013 Friends Science Publishers