phenoleogy, morphology and yield characteristics of two echinochloa weed species

the experiment was performed to evaluate the morphological, phenological and yield aspects of two different echinochloa species, including barnyardgrass (e. crus-galli) and watergrass (e. orizoides) as a new-introduced weed species. the study was conducted as a 2-years pot-experiment under outdoor condition at rice research institute of iran (rrii) in rasht. the results demonstrated that; time to reach the final height, final leaf appearance in the main stem, first tiller and inflorescence appearance, seed filling initiation, and seed maturity were earlier, and grain yield, harvest index, and 100-seed weight were higher, in watergrass compared with barnyardgrass. however, the seed filling duration was longer, and final number of leaves and tillers, biological yield and shattering percent were lower for watergrass than those of barnyardgrass. time to final tillering, maximum height, flag leaf and main stem panicle length showed no significant differences between the two species. therefore, some traits such as shorter life-cycle, higher grain yield, and heavier seeds, will aid the new-introduced species to extend more successfully.