Abstract
This study was designed to evaluate allelopathic substances extracted from shoot, rhizome and inflorescence of johnsongrass which obtained and evaluated for controlling seed germination and early seedling growth of four different weed species, namely, wild oat (Avena fatua L.), ryegrass (Lolium temulentum Gaud.), grass pea (Lathyrus sativa L.) and syrian cephalaria (Cephalaria syriaca (L.) Schard. The results indicated that the percent of seed germination and early seedling growth of all weed species were significantly lower under three extracted substances as compared to those control of treatment. However, rhizome extract exhibited the highest impact, mainly on the length and weight of radicals in comparison to the length and weight of plumule, which is exhibited radical growth of wild oat, ryegrass and syrian cephalaria 100%. This study demonstrates that under restricted conditions, the potential exists for inhabiting percent weed germination and early seed growth but indicates that weed origins need to be factored in modifying allelopathic responses may be used as a bioherbicide.
