Allelopathy in Allelopathy in PlantsPlants

Mary Kate MoranGrade 9

ProblemProblem• Will alfalfa leaf extract have an effect on the

growth or germination of seeds?

ResearchResearch• 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

HypothesisHypothesis• If alfalfa leaf extract is used in place of water on

the seeds, their growth with be adversely effected.

MaterialsMaterials• 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

ProcedureProcedure• Preparation of alfalfa extract• Preparation of trials in petri dishes

o Independent Variable – alfalfa extracto Dependent Variable – growth of seedso Control – trials receiving watero 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

DataData

DataData• 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

ConclusionConclusion• 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

Works CitedWorks 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. <http://edis.ifas.ufl.edu/ hs186>.

• International Society of Chemical Ecology. “Allelopathy.” International Society of Chemical Ecology. N.p., n.d. Web. 29 Sept. 2011. <https://sites.google.com/ a/ chemecol.org/ welcome/ science/ allelopathy>.

• University of Illinois. “Allelopathy and Autotoxicity in Plants.” Refdoc.fr. N.p., n.d. Web. 25 Sept. 2011. <http://cat.inist.fr/ ?aModele=afficheN&cpsidt=5526698>.