Eucalyptus Globulus' Effect on the Germination of Radish Seeds
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The purpose of the project was to determine whether Eucalyptus globulus had an effect on the germination of radish seeds. It was hypothesized that Eucalyptus globulus would have a negative effect on the germination of the seeds and their growth.
Before a seed can germinate it must first shed the seed coat, a protective outer layer that protects the seed from parasites, injury, and unfavorable temperatures. Inside the seed coat is the embryo which contains the root and first leaves of the plant, called cotyledons. After the seed coat has been shed the root emerges first so that it can absorb water and nutrients. After the roots have come out of the embryo the cotyledons will follow. Some seeds need certain conditions to germinate and go…show more content…
Allelopathic chemicals can also exist in soil, affecting the surround plants and those planted afterwards. Studies have shown that Leucaena leucocephala, a tree promoted for water conservation and revegetation, contains a toxic amino acid in its leaves and foliage that prevents the growth of other trees but not its own seedlings. Research has also shown that this species reduces the yield of wheat and increases the yield of rice. Other allelopathic plants include mango, box elder, broccoli, and Eucalyptus. A study was conducted at Gomal University that tested the allelopathic effects of Eucalyptus camaldulensis L. on the germination and seedling growth of wheat. The leaves of E. camaldulensis trees were washed and dried and then filtered to create a one hundred percent solution as well as ten percent, fifteen percent, and twenty percent. These solutions were tested on twelve varieties of wheat. The results showed that there was a significant decrease in germination counts with increasing levels of Eucalyptus aqueous extract concentration. All twelve varieties of wheat were adversely affected by the twenty percent concentration of Eucalyptus extract. It was observed that there was a direct relationship between the number of normal seedlings and the extract concentration. The results suggested that the E. camaldulensis L. leaf aqueous extract could reduce normal seedlings even in low concentrations.