Essential oil from Tunisian Lamiaceae as crop germination inhibitors

The essential oil obtained from rosemary (Rosmarinus officinalis L.) and pennyroyal (Mentha pulegium L.) have been analyzed by GCMS and tested for their allelopathic properties on the seed of two crops (Raphanus sativus L. and Lactuca sativa L.), with the aim to evaluate in vitro their potential as germination inhibitors. The essential oil composition varied with the species, 1,8-cineole (26%) and camphor (23%) being the main constituents of rosemary and pulegone (45%) that of mint. This latest essential oil inhibited completely the germination of crops. The oil of rosemary inhibited completely the germination of Lactuca and showed for Raphanus germination values that were not significantly different from the contro