| The Effect of Capsaicin on the Growth of Sunflowers | |
Researched by Stockton B.
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The purpose of this experiment was to determine the effect of pepper extract on the growth of sunflowers. Pepper spray is often used to prevent insect damage so it is important to know if it can damage plants like a sunflower.
I became interested in this idea because I have always liked sunflower seeds, and wanted to find a better way of growing them.
The information gained from this experiment may help the farming of
various plants, especially sunflowers. If pepper spray is harmful to plants
then it should be used very cautiously to control insects.
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My hypothesis was that the greater amount of capsaicin (pepper extract), the less growth of the sunflower.
I based my hypothesis on the fact that this particular chemical in peppers
is fairly harmful, and if used on a plant it would most likely damage it,
according to Wilbur Scoville, the man who invented the first way of measuring
heat of chili peppers.
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- The constants in this study were:
- The soil type;
- The amount of soil;
- The amount of time for growing (two weeks);
- Size of pot;
- Type of sunflower;
- Ph level of water;
- Amount of sunlight;
- Amount of seeds in pot (4 seeds);
- Amount of water given.
The manipulated variable was amount of capsaicin applied to each
plant.
The responding variables were the height and mass of the plant after one month.
To measure the responding variable first measure the height with a millimeter
ruler, then use a triple beam balance to measure the mass of the plants
after they have been plucked and cleaned of dirt.
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| Quantity | Item Description |
| 3 | Round flowerpots (Same size and shape) |
| 12 | Sunflower seeds (same species) |
| 1 | Small, round dish |
| 4 | Tissues |
| 1 | Container of diluted capsaicin |
| 1 | Triple beam balance scale |
| 1 | Millimeter ruler |
| 1 | 100 ml graduated cylinder |
| 1 | Long plant lamp |
| 2 | Aluminum trays |
1. Place a large amount of tissue on a small tray.
2. Set 12 healthy, un-cracked sunflower seeds on the tissue.
3. Place a bit more tissue on top of the seeds.
4. Keep in safe, warm place.
5. Water twice a day until seeds are germinated. (Each seed has a white
root growing out of them, poking out about 1 centimeter. )
6. Label each of 3 pots with amount of capsaicin.
7. Put 650 ml of potting soil in each flowerpot.
8. Poke hole about 4. 5 centimeters deep in each pot’s soil.
9. Place 4 sunflower seeds in each of 3 flowerpots.
10. Gently cover hole entirely without pushing or packing down soil.
11. Set two pots in one tray and the third in the second tray.
12. Set lamp about 1 foot above the flowerpots.
13. Water regularly with 200 ml a day until they are about 18 cm tall.
14. Write in journal.
15. Take a picture of fully-grown sunflower.
16. Add 116 ml of capsaicin to 116 ml of water.
17. Mix well until capsaicin is spread completely through the water.
18. Repeat step with 232 ml of water.
19. Repeat step 17.
20. Write in journal.
21. Water each sunflower equally until the bottle is empty.
22. Leave for 1 full day and return.
23. Inspect plant carefully until positive of either the plant changing,
or staying the same.
24. Take a picture of the sunflower.
25. Label both pictures; name early one “before” and the later one
“after”.
26. Pluck, wash, and dry each flower, keeping them in their correct
groups.
27. Measure and weigh each plant with triple-beam balance.
28. Write experiment results in journal.
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The original purpose of this experiment was to determine whether capsaicin (pepper extract) would affect sunflowers.
The results of the experiment were that capsaicin would make a fair
pesticide; the sunflowers’ growth was completely random. The plant with
0 ml of dilution grew to 27 inches and weighed 63 grams, and the one with
232 ml of dilution grew smaller.
My hypothesis was that the more capsaicin added the worse the plant’s health would be.
The results indicate that the hypothesis should be rejected because the sunflowers growth was not stunted. There was no change in the plants at all.
Because of the results of this experiment, I wonder if growing peppers and sunflowers in the same pot would control insects without damaging the sunflowers. I wonder if other plant species would also be harmed.
If I were to conduct this project again, I would have done many things
differently. First of all, I would use much more exact measurements. I
would also grow them when it is warmer, to be able to grow them outside,
in the sunlight and real soil. I would have liked to have more plants per
group as well, and dilute the pepper spray more.
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I would like to thank the following people for helping make my project possible:
- My parents for helping me grow and help take care of the plants.
- Mr. Newkirk for giving me supplies and for helping me just about every step of the way.
- Mrs. Helms, also for helping me and give me what I needed when I needed it.
- Mrs. Hostetler for helping teach me about science.
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