1. Allelopathy in Plants Mary Kate Moran Grade 9

2. Problem Will alfalfa leaf extract have an effect on the growth or germination of seeds?

3. Research Plants will compete for resources physically and chemically Allelopathy – the chemical inhibition of the growth of one plant by another Allelopathic chemicals can be found in several locations on the plant Alfalfa is known to have allelopathic tendencies, particularly on radish seeds

4. Hypothesis If alfalfa leaf extract is used in place of water on the seeds, their growth with be adversely effected.

5. Materials 150mL beaker 18 9-cm petri dishes 50mL flask filter paper 2 1mL syringes Alfalfa shoots Distilled water 60 radish, pea, and turnip seeds cheesecloth

6. Procedure Preparation of alfalfa extract Preparation of trials in petri dishes o Independent Variable – alfalfa extract o Dependent Variable – growth of seeds o Control – trials receiving water o Constants - time duration, types of seeds, dishes, location, temperature Addition of 1mL distilled water or 1mL alfalfa extract twice over one week period Observation of trials

7. Data

8. Data Seeds started sprouting on Day 4 Control and Experimental groups did not display noticeable differences until Day 6 Radishes displayed greatest difference Peas displayed smallest

9. Conclusion The hypothesis was that the alfalfa leaf extract would have an adverse effect on the growth of seeds. The hypothesis was supported. o Growth was adversely affected in all seeds. Alfalfa had the greatest allelopathic effects on radishes. Peas showed the greatest number of seeds germinated and germinated most fully, therefore alfalfa had the least allelopathic effects on peas. Possible sources of error and furthering of experiment

10. Works Cited Coder, Kim D. Allelopathy in Trees. University of Georgia. PDF file. http://warnell.forestry.uga.edu/ ‌ service/ ‌ library/ ‌ for99- 004/ ‌ for99-004.pdf DeLacy, Margaret, and Leslie Seiger. A Study of Allelopathy in Plants. Washington, DC: n.p., n.d. N. pag. Print. Ferguson, James J. “Allelopathy: How Plants Suppress Other Plants.” EDIS. University of Florida, n.d. Web. 25 Sept. 2011.. International Society of Chemical Ecology. “Allelopathy.” International Society of Chemical Ecology. N.p., n.d. Web. 29 Sept. 2011.. University of Illinois. “Allelopathy and Autotoxicity in Plants.” Refdoc.fr. N.p., n.d. Web. 25 Sept. 2011..