Juglone as an Inhibiter of Growth of Herbaceous Plants

BIOL2082

11/06/2013

Abstract

Allelopathy is shown with juglone produced by the black walnut tree. This chemical inhibits the growth of surrounding plants, allowing the walnut tree a better chance of survival. This experiment tests the hypothesis that higher juglone concentrations inhibit the growth of surrounding plants. The effects of juglone were tested by observing the amount of herbaceous plants surrounding walnut and non-walnut trees in a deciduous forest. The soil surrounding these trees was also collected and tested for juglone by extracting methylene chloride. Tests were also performed to determine the significance of the data collected. An ANOVA test resulted in significance between the juglone concentrations in each soil, with walnut soil collected 5m from the tree having the most juglone. However, there was not significance in the number of herbaceous plants growing around each tree. There was also not a significance in the number of plants grown in collected samples of the different soils at 5m and 1m from each tree.

The hypothesis was rejected since two tests showed equal growth in all plants despite soil type. Further research should be conducted to determine what the cause was for plants growing in juglone soil to grow equally as those that grew in juglone free soil.

Introduction

Allelopathy is a type of relationship where one plant produces a material that can affect the growth of another plant. This relationship is seen in all different types of plants, and can be useful in order to understand how different substances affect different species of plants. This understanding can be used in medicinal productions, pesticides, and other chemical uses. M. Worthington and C. Reberg-Horton (2013) studied the allelopathy's ability to make pesicides to prohibit weed growth in important grains. The best resistant crops are...