Allelopathic potential effects of Rhazya stricta plant extract on growth control of Cuscuta campestris weed seedlings

Among weeds, parasitic plants have more profound effects on host plants. Due to its wide geographical distribution, high host range, and inefficient management methods, the Cuscuta  (Cuscuta campestris) plant has become one of the most damaging parasites. The present study aimed to control the Cuscuta weed biologically. To this end, an experiment was conducted to investigate the allelopathic effects of the extract of the Rhazya Stricta plant on the control of this weed population in the laboratory of Velayat University of Iranshahr. The experiment was conducted as a completely randomized design with three replicates. In this experiment, negative allelopathic effects of different extracts of the R. stricta plant including acetone, aqueous, methanolic, ethanolic, and hydroalcoholic extracts on the Cuscuta were investigated in comparison with the distilled water (as control treatment). The results of this study revealed that the aqueous extract of R. stricta significantly decreased the germination percentage, germination vigor, germination rate, root length, and stem length of the Cuscuta compared to those of other treatments. Also, the other extracts of the leaves of the R. stricta plant have significant inhibitory effects on seed germination and seedling growth of the tested parasite weed species compared to those of control treatment (distilled water) suggesting the availability of inhibitory chemicals in the leaves of R. stricta to control the Cuscuta weed. It is suggested to test the negative effects of R. stricta leaf and stem extracts, after decomposition, on other weeds and adjacent and sensitive plants to R. stricta.