Evaluating the allelopathic potential of the medicinal plant of Eucalyptus on the characteristics of germination and seedling growth of the plant sensitive to allelochemicals of chickpea in order to reduce water and environmental pollution

An experiment was conducted in order to evaluate the allelopathic effect of water extract from different parts of Eucalyptus on the germination characteristics and seedling growth of the benchmark plant and sensitive to allelochemicals of chickpea in both laboratory and greenhouse conditions in a completely randomized design with three replications, separately. At first, the dried samples were powdered by a mill. For bioassay experiment, a 2% suspension of Eucalyptus leaves and bark along mixture of them was prepared, and then different dilutions of the suspension such as 0 (control), 5, 15 and 20% of the resulting suspension were applied. In greenhouse condition, different amounts of plant residues including 0.5, 1, 2, and 5% by weight of each leaf organ, bark, and their mixture were prepared separately in three kg of loam soil in pots. The pots were kept for 60 days in order to rot and the activity of microorganisms in these conditions. Finally, for bioassay experiment, some characteristics of germination percentage, radicle and shoot length, allometric coefficient, seed vigor index, and in the case of greenhouse experiment, germination percentage, plant length, seedling fresh and dry weight were measured. According to the results, the effect of Eucalyptus organs, different concentrations or amounts of plant residues, and their interaction effect on the characteristics of germination and seedling growth of chickpeas were significant (p<0.05). The intensity of inhibitory and stimulatory effect in chickpea seeds depended on the type of organ and the concentration of aqueous extract or the amount of decayed Eucalyptus