Allelopathy in Plants: Is it Really There?

Allelopathy in Plants: Is it Really There? Rachel French 9th Grade

Problem • Are allelopathic effects present when various seeds are watered with alfalfa extract?

Research • Allelopathy is the competition of limited resources by plants • Comes from the Greek words “each other” and “sensitivity” • Competition takes one of two forms: • Exploitation • Interference • Reduces seed germination and seed growth • Reason why some plants cannot live together • Allelopathic chemicals can be present in all parts of the plant

Hypothesis • If radish, seed rye, and rye grass seeds are separately watered with alfalfa extract, then there will be a negative effect on the germination of the seeds.

Materials • 45mL alfalfa extract • Alfalfa sprouts • 45 mL water • 1 layer of cheesecloth • 45 mL distilled water • 1 roll of paper towels • 60 radish seeds • 60 seed rye seeds • 60 rye grass seeds • 18 petri dishes • 2 5-mL syringes

Procedure • The alfalfa extract was made by straining a mixture alfalfa shoots and water • Each of the 18 petri dishes were labeled and lined with paper towels • 5 mL of either distilled water or alfalfa extract was added to each dish • The seeds were added to their respective petri dishes • The seeds were observed, observations were recorded, and statistics were calculated

Procedure • Tested six times, either with alfalfa extract or distilled water • Independent variable = type of seed • Dependent variable = number of seeds germinated • Control variable = seeds tested with distilled water • Constants = location of the experiment, type of petri dish, the amount of liquid used with each dish, and elapsed time before observation

Data Treatment Results

Data

Data Average Comparisons

Data

Conclusion • Hypothesis supported • More seeds germinated when watered with distilled water • Use a wider range of treatments • Measure germination at multiple points during experiment • Source are to follow

Thanks • Thank you for listening to my presentation • I ask you to further your knowledge of my experiment with any questions

References • Allaby, M. (2004). A Dictionary of Ecology. In Allelopathy. Retrieved November 8, 2009, from Encyclopedia.com website: http://www.encyclopedia.com/doc/1O14-allelopathy.html • Allelopathy. (2006, June). Allelopathy Journal. Retrieved November, 2009, from Allelopathy website: http://allelopathy-journal.com/allelopathy.aspx • Dailey, R. (2008, January 19). Allelopathy. Retrieved November 8, 2009, from Suite101 website: http://www.suite101.com/blog/bobcajun/allelopathy • Ferguson, J. J. (2009). What is Allelopathy? In Allelopathy: How Plants Supress Other Plants. Retrieved November 6, 2009, from Universtiy of Florida website: http://edis.ifas.ufl.edu/HS186 • A Study of Allelopathy in Plants. (2000). In Encouraging Student Biological Research (pp. 21-51). Jefferson City, MO: National Association of Biology . • Willis, R. J. (2007). Chapter 1. In The History of Allelopathy (pp. 1-14). Retrieved from http://books.google.com/books?id=C-nPBYjDAjYC&pg=PA3&dq=allelopathy+plants#v=onepage&q=allelopathy%20plants&f=false

Allelopathy in Plants: Is it Really There?