Have you ever felt like you needed your own space? Sometimes we all need to be alone. Plants and trees need to have their own space, too. How do you get your own space? You can walk away or shut your door, but what can plants do? They can't walk or run anywhere. Plants have a different way of getting their own space. They use allelopathy.
is a chemical process that a plant uses to keep other plants from growing
too close to it. Some pine trees are allelopathic. When their needles
fall onto the ground and they keep unwanted plants from growing near the
Does Allelopathy Work?
Impact: Allelopathy means "Power"
Scientists study allelopathy and use their research to find natural, healthier herbicides and pesticides to stunt or kill specific unwanted plants and insects, but not kill the plants we want.
Try This: Experimenting with Allelopathy
1: Look for Signs of Allelopathy in Your Neighborhood
Choose several of your favorite trees and collect about 10 leaves from each of them. Look around the trees and try to determine if they are allelopathic. (At the base of the tree is there little or no vegetation?)
Then place the leaves in a plastic bag and label the bag with any known fact about the tree, such as its location, whether it shows signs of allelopathy or other distinguishing features. Try to identify the plant but if you are having trouble go to your local library and ask the librarian for a field guide about trees. Or visit a local plant nursery and ask their plant experts. If you do not use the leaves immediately, place the bag in the refrigerator for up to 2 days and identify and analyze them later.
If you suspect that the trees show signs of allelopathy you can test out your theory in Experiment 2.
2: Testing whether this Tree is Allelopathic?
or three leaves from a few different trees (you could use the same leaves
collected in Experiment 1) and tear them
into small pieces. Put the pieces from each tree into separate glass jars
with some water. Each of the mixtures should have more plant matter than
water. When you make up the jars, make sure you repeat the same procedures
for all of them.
Now you are ready to start the main part of the experiment.
As a side note, one paper towel should be dampened with plain water to serve as the control. You can use the control to compare with your experimental seeds. Using one paper towel with plain water is also important in case something goes wrong with the experiment. One possible problem might occur if the chemicals in your water are killing the seed instead of the leaf chemicals killing the seed.
Analyze your Results:
Make a Conclusion:
Experiment ideas courtesy of Dragonfly Pages.
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