Seed Germination in Acidic Solutions

By: Madison Welsh

9th Grade

Problem

• This experiment was designed to test the effect of acids on plant seeds.

• The project is designed to show whether or not pea seeds will germinate in vinegar, lemon juice, or water.

• In addition, the experiment will show whether or not the acids have a corrosive on the seeds.

Research

• Vinegar has a pH level of 2.4 to 3.4.• Lemon juice has a pH level of 2.3• Water is not a base or an acid, so its pH level is

7. • pH levels measure the acidity of solutions.• It also measures the activity and concentration

of hydrogen ions.• A solution with a pH level under 7 is an acid.

Research

• pH stands for the power of hydrogen.

• Citric acid such as lemon juice has a corrosive effect on rust and is often used for cleaning.

Research Continued

• Seed germination is the growth of a plant inside its pod.

• All developed seeds have an embryo inside.

• Water, oxygen, light, and certain temperatures are required for seed germination.

Hypothesis

• If pea seeds are soaked in lemon juice, vinegar, or water, then the seeds soaked in water will germinate first, followed by the lemon juice, and then the seeds soaked in vinegar will germinate last.

• The seeds soaked in vinegar and lemon juice will germinate after the seeds soaked in water.

Hypothesis Continued

• The seeds soaked in vinegar and lemon juice will germinate after the seeds soaked in water because they are both acidic solutions.

• The high activity of the hydrogen ions will slow the germination of the seeds, but will not prevent it because the seeds will still receive hydrogen and oxygen, which will allow them to germinate.

Materials

480 pea seeds

4 plastic containers

1 liter of vinegar

1 liter of lemon juice

1 liter of water

18 paper towels

Procedure

A paper towel was rinsed in vinegar and placed in the bottom of a plastic container.

40 pea seeds were placed on the paper towel and covered with another paper towel soaked in vinegar and the lid was placed on top.

Then, another paper towel was soaked in lemon juice and placed in the bottom of another plastic container.

40 pea seeds were placed on the paper towel and covered with another paper towel soaked in lemon juice and the container’s lid was placed on top.

Procedure Continued

• Finally, a paper towel was soaked in water and placed in the bottom of a plastic container.

• 40 seeds were placed inside the container and covered with another paper towel soaked in water.

• The container was covered by the lid.• All three containers were observed over a

48 hour period.

Procedure Continued

• This procedure was repeated twice after each 48 hour period.

• The independent variable is which solution the seeds were soaked in (water, lemon juice, or vinegar.)

• The dependant variable is the rate of germination and/or the amount of seeds that germinated.

• The constants are the containers used, the temperature, the paper towels, and the pea seeds.

Data

Conclusion

• Parts of the hypothesis were correct but others were not.

• The hypothesis stated that the seeds soaked in water would germinate first, followed by the seeds soaked in lemon juice, and finally the seeds soaked in vinegar.

• However, all of the seeds sprouted after 48 hours, but the number varied for each solution.

Conclusion Cont.

The acids killed the majority of the pea seeds soaked in vinegar and lemon juice.

In this respect, the hypothesis was correct because the vinegar killed the most seeds, followed by the lemon juice, but the solutions did not slow or quicken the growth.

The experiment could be continued by repeated the experiment with different acids or by planting the seeds that germinated in the acids.

Works Cited• "Acetic Acid." EdInformatics. N.p., n.d. Web. 29 Nov. 2009.

<http://www.edinformatics.com/ math_science/science_of_cooking/acetic_acid.htm>. "Acid Rain Experiments- Experiment 7- Observing the Influence on Acid Rain on Plant Growth." Environmental Protection Agency. U.S. Environmental Protection Agency, 8 June 2007. Web. 20 Nov. 2009. <http://www.epa.gov/acidrain/education/experiment7.html>. Carpi, Anthony. "Acids and Bases: An Introduction." Vision Learning. N.p., 2003. Web. 29 Nov. 2009. <http://www.visionlearning.com/library/module_viewer.php?mid=58>. Cummins, R. Hays. "Final Presentation of the Effect of Acid Rain on Plants." Jr. Science. Miami University, 10 Dec. 2008. Web. 20 Nov. 2009. <http://jrscience.wcp.muohio.edu/nsfall02/ FinalArticles/FinalPresentationofTheEff.html>. Holt, S. A. "How to Grow Mint Indoors." eHow.com. N.p., n.d. Web. 13 Nov. 2009. <http://www.ehow.com/how_4493938_grow-mint-indoors.html>.  

Thank you!

• Thank you for listening to my project!

Any questions?