Lab report on Effect of black walnuts on surrounding vegetation

Essay by bbtCollege, UndergraduateA+, May 2004

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When one views the ground nearby a black walnut tree, a view of life is very sporadic and almost desolate. Many large trees provide much shading but the grass seems to grow even more economically in these areas. From these observations it appears that the black walnuts contain some type of ingredient that serve as a toxin for the plant life around the base of the tree.

At first, a black walnut was taken and the outer layers were collected. Along with adding distilled water the black walnut remains were macerated together forming a thin liquid substance but still a little thicker then water. Small Petri dishes were put to the side while paper towels were cut to fit inside the dishes. This was to serve as a sponge like material for the water and walnut mix that was soon to be contained. The first dish held distilled water.

The black walnut mix was then poured into the second and third Petri dishes. Grass seed was added to the first dish with water and the second dish with the black walnut mixture. The columbine seed was sprinkled into the third dish that also contained the mixture. All three dishes were sealed with tape and labeled. This experiment was to identify the cause of the walnuts to the seeds that would be soon germinating. Approximately a week went by and more distilled water was added to maintain moisture for the seeds in each dish.

After the first checking of the seeds, the grass in the distilled water had germinated and grew to about 2 inches in length. The columbine and grass seed in the mixture of distilled water and black walnut shells had remained dormant. After adding more water to all three dishes, they were sealed again and put...