The aim of the project was to determine if Eucalyptus globulus had an effect on the germination of radish seeds. It was hypothesized that Eucalyptus globulus would have a negative effect on seed germination and growth. Before a seed can germinate, it must first shed its seed coat, a protective outer layer that protects the seed from pests, injury and unfavorable temperatures. . Inside the seed coat is the embryo which contains the root and first leaves of the plant, called cotyledons. Once the seed coat is lost, the root emerges first so it can absorb water and nutrients. Once the roots emerge from the embryo, the cotyledons will follow. Some seeds need certain conditions to germinate and go through a dormant period before germinating. Seed dormancy ensures that the seed is protected until conditions are right for it to germinate. Allelopathy is the beneficial or harmful effect that one plant has on another. This occurs through the release of chemicals from plants through leaching, exudation from roots, volatilization and decomposition of residues. Allelopathy can affect a plant's growth, occurrence, succession, dominance, diversity, and productivity. While allelopathy initially referred to the negative effects of one plant on another, it was broadened to include beneficial effects. Common effects of plant allelopathy are reduced seed germination and seedling growth. Although there is no common target site for allelochemicals, common sites of action are cell division, nutrient uptake, pollen germination, and photosynthesis. Allelopathy involves the interaction of phenolic compounds, flavonoids, terpenoids, alkaloids, steroids, carbohydrates and amino acids. Sometimes mixtures of...... middle of paper ......es. Leachate from stem runoff and litter falls are responsible for the allelopathic effects of Eucalyptus on other plants. Eucalyptus oil can be obtained by distillation of eucalyptus leaves. The oil is used for medicinal, perfumery and industrial purposes. Although eucalyptus oil is used as a decongestant and treatment for bronchitis, if taken in large doses in pure form, it is toxic. The lethal dose of eucalyptus oil for an adult is approximately 0.05-0.5 ml per kg of body weight. The component of eucalyptus oil that gives it several uses is eucalyptol, also known as cineole. http://www.wssp.org.pk/14,1-2,2.pdfhttp://www.absoluteastronomy.com/topics/Eucalyptolhttp://www.fao.org/docrep/V5350E/V5350e07.htmhttp: / /www.jtropag.in/index.php/ojs/article/viewFile/50/45