Evaluation of the Efficacy of Some Plant Extracts as an Alternative to Chemical Weedicides in Controlling on Cyperus rotundus L

Two experiments were carried out during the summer season, 2016, in the green house / Department of Biology/Collage of Education, Samarra University, to evaluate the activity of three aqueous extract of leaves of Nerium (Nerium oleander L.),olives (Olea europaea .L) and castor (Ricinus communis.L), on control of tuber germination and growth of seedling of Cyperus rotundus L as an alternative for chemical pesticides. Experiments applied according to the complete randomized design (CRD) with four replicates. The experiments included two factors: the first factor plant species (three plant species),and the second factor concentration of plant extracts (2.5%, 5% and 10%) and their impact on germination rate and inhibition of seedling growth. The results of the first experiment recorded inhibition percentage reached (90%) at 5% and 10% from Nerium extracts compared with the same concentrations from Olive and Castor which, recorded inhibitory rate reached (30-40%) respectively. While the concentration of 2.5% was the lowest inhibition rates for germination ratio of all plant extracts under study. The second experiment showed effect of the Nerium extract at a concentration (10%) by recording completely inhibition ratio (100%), compared with the same concentrations of Castor and Olive extracts, which recorded the lowest mean growth inhibitory for all extracts. The results of the current study indicate the possibility of using natural products of plant origin as alternatives to chemical pesticides as one of the means of biological control in the management program agricultural sector with further studies of the future.