Fatemeh Mousavi Nadar, Hamzeh Amiri,
Volume 11, Issue 1 ((Spring and Summer) 2024)
Abstract
Extended abstract
Introduction: Allelopathy is the same as chemical warfare among plants. Today, global human efforts in agriculture are allocated towards reducing chemical pesticides and introducing new biological methods to control weeds. One of the proposed solutions for weed management is isolating allelochemical compounds from plants and using them as natural herbicides.
Materials and Methods: The present study was conducted to investigate some germination and biochemical properties of the weeds Taraxacum officinale, Achillea millefolium, Rumex acetosa, Althaea officinalis, and Amaranthus retroflexus As affectedby aqueous extract concentrations from the leaves of Thuja orientalis. The experiment was carried out in a completely randomized design with three replications. Aqueous leaf extracts of Thuja orientalis were used at concentrations of 0, 5%, 10%, 20% and 30%.
Results: The results showed that the aqueous leaf extract of Thuja orientalis had a significant effect on all the studied traits, and the highest inhibitory effect was observed at a concentration of 30% of the extract. In Taraxacum officinale, Achillea millefolium, Rumex acetosa, Althaea officinalis, and Amaranthus retroflexus, the germination percentage (93.33%, 88.55%, 48.3.%, 27.36%, and 40.5%), germination rate (100%, 76.36%, 39.28%, 71.72%, and 57.47%), germination coefficient (100%, 77.5%, 39.56%, 70.9%, and 51.47 %), germination index (57.2%, 72.6%, 84.61%, 72.5%, and 85.6%), peak value (67.9%, 48.7%, 61.4%, 70.9%, and 57%), germination value (43.2%, 39%, 46.9%, 53%, and 59.8%), daily germination speed (100%, 77.5%, 39.56%, 70.9% and 56.02%), seed vigor index (69.9%, 92.7%, 97.5%, 93.2%, and 92.1%), and relative water content (53.1%, 38.35%, 35.37%, 37.65%, and 47.1%) decreased compared with the control, while the mean germination time (51.6%, 71.6%, 50.7%, 60.3%, and 60.5%) and ion leakage (24.23%, 15%, 18.33%, 17.3% and 20.23%) increased compared with the control. The results of this study showed that the seeds of Taraxacum officinale were more sensitive to the inhibitory effects of the aqueous leaf extract of Thuja orientalis compared with the seeds of other studied weeds.
Conclusions: Considering the presence of monoterpene compounds such as alpha-pinene, sabinene, beta-phellandrene, and delta-carene, as well as phenolic compounds in Thuja orientalis, it seems that the allelopathic effects of this plant are mainly due to the presence of these secondary metabolites. The significant allelopathic effects of the aqueous leaf extract of Thuja orientalis at high concentrations can make it a potentially effective and environmentally friendly tool in controlling the studied weed species (Taraxacum officinale, Achillea millefolium, Rumex acetosa, Althaea officinalis, Amaranthus retroflexus) in this research.
Highlights:
- Leaf extract of Thuja orientalis has significant allelopathic effects on seed germination of the studied plants.
- Among the studied seeds, the seeds of the Taraxacum officinale plant are more sensitive to the aqueous extract of Thuja orientalis compared with others.
- The aqueous extract of Thuja orientalis leaves led to undesirable effects on the growth and seed germination of the studied plants by damaging cellular membranes.
