The Effect of Eucalyptus and Orange Leaves Added to the Soil on Germination and Growth of Four Ornamental Plants

The experiment was conducted on green house to investigate the addition effect of fresh leaves of Eucalyptus (Eucalyptus camaldulensis L.) and Orange (Citrus sinensis L.) on seed germination and growth of four species of the ornamental plants ( Dimorphothica aurantiaca L., Chrysanthemum carinatum L., Calendula officialis L. and Gaillardia pulchella L.). The results showed that the effects of fresh leaves of Eucalyptus and Orange which added to the soil (Separately) caused the reduction in the percentage of seed germination of the plants. As for growth a decrease in plants planted in soils containing fresh Eucalyptus leaves, while an increase in plants planted in soils containing Orange leaves. The results also showed different in the responses of the ornamental plants species to the allelopathic effect of Eucalyptus and Orange leaves added to the soil, it appeared that Dimorphothica aurantiaca L. and Chrysanthemum carinatum L. were more sensitive to the allelopathic effect for these trees, while Calendula officialis L. and Gaillardia pulchella L. were less sensitive for these trees.