Hello this is my paper

Do Radish Seedlings Produce Allelopathic Chemicals?
Do you ever feel that you need your own space? When you feel you want to get away from other people, you can walk away or leave the room. Plants and trees need their own space in order to obtain sufficient amounts of nutrients from the soil and sunlight. Plants, of course, are unable to move away. However, some plants use chemicals to keep other plants from growing too close. This process is called allelopathy.

Some scientists believe that germinating radish seeds give off a chemical that interferes with the germination of other seeds. A few years ago, a group of scientists published a scientific paper that demonstrated that germinating radish seeds have an allelopathic effect upon lettuce seeds. A year later, another group of botanists repeated the experiment. The second group claimed that the radish seedlings had no allelopathic effect upon lettuce seed germination or growth. Now it is your turn to determine if radish seedlings do have an allelopathic effect upon lettuce seeds.

Suggested Materials: plain white paper towels scissors radish seeds containers for growing seeds pencil lettuce seeds water hand lens Suggested Procedure:
1. Fold a paper towel in half. Fold it in half again. Place the bottom half of a dish in the center of the folded towel. With a pencil, trace the bottom of the container onto the folded paper towel. Cut out circles. Insert all the paper circles in the bottom half of the petri dish.

2. Using the same procedure, cut paper circles and place them in the other three containers.

3. Label the bottom of one container “lettuce.” Label the bottom of another container “Radish.” Label the bottom of the third container “Lettuce and Radish seeds--started together.” Label the four container “Radish--Lettuce seeds added after radish germination.”

4. Saturate the paper circles in each container with water. Carefully pour off any excess water.

5. Place 25 radish seeds in the dish marked “Radish.” Place 25 lettuce seeds in the dish marked “Lettuce.” Place 25 radish and lettuce seeds in the dish marked “Lettuce and Radish--started together.”

6. In the remaining dish, place 25 radish seeds. You will add lettuce seeds after these seeds germinate.

7. Place the containers where they will not be exposed to cold temperatures. Maintain a temperature between 15oC and 25oC.
8. After two days, examine the containers every day with a hand lens. Look for signs of seed germination. Record your observations daily for fourteen days, see example Data Table.

9. As soon as you notice some of the seeds in the dish marked “Radish-Lettuce seeds added after radish germination” have germinated, add 25 lettuce seeds. Wait two days before observing and recording your observations for this setup.

10. At the same time compare radish seeds and cabbage seeds. Set up containers with 20 cabbage seeds and 20 radish seeds. Observe and record,

11. Set up a container with 25 radish seeds. Let them germinate for seven days. Then discard the radish seeds and replace them with 25 lettuce seeds on the same paper toweling. What do you hypothesize will happen to the lettuce seeds after seven days? Record your observations and make comparisons between the previous activity.

Example Data Table
Number of Seeds Germinated
Day
Lettuce (Container 1)
Radish (Container 2)
Lettuce/Radish Started Together (Container 3)
Radish/Lettuce Added after Germination (Container 4)
3

4

5

6

7

Number of seeds germinated

Percentage of seeds germinated

Tips:
-Define allelopathy, what is it and what does it do to the plants? what are the effects?
-Talk about germination, good explanation
-Find similar experiments
-Find resources
-Think about the experiment, what you want to grow the seed in
-DON’T WAIT ON RESEARCH/QUESTIONS

1998 J. Weston Walsh, Publisher
Watch Hands on Science Series