161 Akhtar et al. Int. J. Biosci. 2013 RESEARCH PAPER OPEN ACCESS Phytotoxic potential of Calotropis procera against germination behavior and morphological growth performance of lentil (Lens culinaris) Rizwan Akhtar 1 , Syed Amir Manzoor 1* , Muhammad Athar khaliq 2 , Hameed ud Din 2 , Muhammad Faseeh Iqbal 1 , Irshad Hussain 3 , Hafiz Muhammad Imran Umar 1 1 Faculty of Agriculture Science and Technology, Bahauddin Zakariya University Multan, Pakistan 2 Department of Agronomy, University of Agriculture, Faisalabad, Pakistan 3 Department of Plant Pathology, University of Agriculture, Faisalabad, Pakistan Key words: Allelopathy, Calotropis procera, lentil, germination behavior. doi: http://dx.doi.org/10.12692/ijb/3.12.161-168 Article published on December 18, 2013 Abstract This study was carried out to assess the allelopathic potential of Calotropis procera against lentil. Four different concentrations of Calotropis procera leaf extracts (100%/, 75%, 50% and 25% concentrated) were used to irrigate pots containing lentil seeds. Allelopathic effects of C. procera on lentil crop were gauged using different germination indices and physical growth parameters like root and shoot growth, number of leaves and branches and other morphological growth parameters. Results concluded that C. procera leaf extract has obvious suppressing effects on lentil since at higher concentration of leaf extract, lentil seeds showed significantly lower germination percentage and reduced growth in all physical growth parameters. * Corresponding Author: Syed Amir Manzoor  amir.kzd@gmail.com International Journal of Biosciences | IJB | ISSN: 2220-6655 (Print) 2222-5234 (Online) http://www.innspub.net Vol. 3, No. 12, p. 161-168, 2013