Science Buddies: "Ask an Expert"

Do plants have emotions?

I'm going to talk to plants. I have three groups: the group that I talk nicely to and compliment; the group I tell how worthless they are and tell them negative things; and the group I don't talk to at all. Each group consists of three of the same plants; the Eskimo Marigold, a polka-dot-plant, and foliage. I have cut the plants to be the same length. I am having trouble finding research on this topic. Please, please, please can one of the experts out there help me find research from a reliable source. My teacher wants to see how far we got in about 4 days he wants us to be midway through and working with the test. Problem: I don't have research. I've tried finding sources online but my teacher says that the source has to be .org .gov or .edu and I can't find a source that has that. I also need a book and fast anyone know a good one?

Hi,

The problem you are having is that no one has published valid scientific data showing that talking to plants has a measurable effect. Your teacher is trying to help you by suggesting that you start your background reading from scientific sources. Unfortunately, although your idea is a creative one, it's not a particularly good idea for a science project.

You have the benefit of time because your project is not due for more than a month. I recommend that you try using the topic selection wizard on the Science Buddies website and look for project ideas that are interesting to you and that can be done in a couple of weeks. All of the project ideas have references that will help you get started on your background research. You can find a scientific principle to study, design a controlled experiment with results that can be measured, and get an "A" on your science project.

Please let us know if you need any more help.

Donna Hardy

Thank you for your suggestion donna, but i tried changing my idea and my teacher would't let me. In a couple of days he wants to see how far the class has gotten. This is my second idea for the project because my first one failed. There is not much i can find on plants having emotions. I tried finding sources online and i am going to the library to find a book soon. Wikipedia is the only source i could find for this topic. My classmates at school say that wikipedia is not a very reliable source because some facts may be true but they can be changed by registered users of that source. If someone out there thinks that wikipedia is a fine source please tell me otherwise. I already know what to do for this project all i need is research any users out there that have come across a website that is reliable please post it up here. I need help asap. As soon as i have research then i can finish the project.

I have just found this website.

http://en.wikipedia.org/wiki/Plant_perc ... aranormal)

Is it a reliable source that i can use?

Hi,

No, this is not a scientific source. Some Wikipedia sites do include a bibliography from the scientific literature, but this one does not. I have searched on your topic and there is nothing that has been published. Scientific sources report the results of controlled experiments that are reviewed by other researchers. Here is an example of a paper on responses of plants to the environment.

http://www.wesleyan.edu/bio/sultan/Curr ... %20'10.pdf

I have an idea for your project, and I will post again very soon.

Donna Hardy

Hi,

It is surprising that your teacher is saying that you have to do a science project on a topic for which there is no scientific basis and therefore there are no published references in the scientific literature. I’m sure people have done experiments on this topic before, but since the scientific method requires some measurable result, no one has published a paper showing that talking to plants has any effect on plant growth. I have access to several databases, and I have searched for a paper on this topic, but I have not been able to find anything.

However, I have an idea for your project. You can do a science project on plants and compare the growth of plants in a control group with other plants grown under exactly the same conditions that you talk to on a regular basis. This would meet your teacher’s requirement that you not change topics. Your hypothesis, of course, would be that you don’t think that talking to plants will affect their growth because you have not been able to find any references to indicate that it will have an effect.

Here is a Science Buddies site that describes how to measure plant growth. What plants are you planning to use? Remember, you will need to keep all other parameters (growth, light, water, fertilizer, soil, and temperature) the same for both groups of plants, except for talking.

https://www.sciencebuddies.org/science- ... owth.shtml

Please note at the bottom of the project, there are several references listed. These are literature references that you could use for a bibliography for your project.

It’s possible that your teacher did not understand the reason for your request to change topics. It’s OK with me if you want to print out this response and show it to your teacher tomorrow. I can help you find a related, but much better topic.If you do this one, you will still learn something about the scientific method, but it would be nice to be able to do a project that you could take to a science fair.

I have another idea and I will post again soon.


Donna Hardy

Hi,

If you read the review paper I posted earlier today, you know that plants respond to their environment and that light, food, and water are very important to their development. Here are some project ideas on the Science Buddies website that you could do.

Here’s one on fertilizer:

https://www.sciencebuddies.org/science- ... p012.shtml

Here’s one on light.

https://www.sciencebuddies.org/science- ... p015.shtml


Here’s one on gravity.

https://www.sciencebuddies.org/science- ... p014.shtml

Moon and tides:

https://www.sciencebuddies.org/science- ... p009.shtml

Ultraviolet light.

https://www.sciencebuddies.org/science- ... p012.shtml

Biomes:

https://www.sciencebuddies.org/science- ... p046.shtml

I found another very interesting reference, which I have attached to this post, which reports the response of plants to the chemical signals produced by bacteria. Please try reading this article to see if you can understand it. Please notice that this is a review article, and reports the results of a number of published papers on a related topic. This would be a great topic for a science fair project.

Each of the projects include a bibliography and there are lots of scientific papers and books on each subject that you could use for a project. You would still need to do background reading and develop the topic so you could design an experiment that would have measurable results.

Please let me know if you have any questions about doing any of these projects.
Donna Hardy

Dear Donna,
Thank you for your help. I am downloading the software to view the sites of your recent posts.I am sure that they will be a big help.

Thank you so much,
Kelsey

Here are some recent sites I have found:

http://www.ecopsychology.org/journal/ga ... _cock.html

http://www.maximumyield.com/article_sh_ ... reVar=true

http://jrscience.wcp.muohio.edu/nsfall0 ... timul.html

http://www.bio.net/mm/plant-ed/2006-Dec ... 08153.html

Are they reliable or useful to my project's research in any way

Hi,

Excellent job on your literature search!

Yes, all of these sites contain information related to your topic. The first two, while appearing to report on scientific research, actually do not contain any scientific references. Some people would describe these reports as pseudoscientific.

The third one is very interesting, and appears to include scientific references, however, if you notice, several of the references were published in journals like the Journal of Alternative and Complementary Medicine, which is not a peer-reviewed publication. There is one reference that was published in Plant Physiology, which is a valid scientific journal and included test on groups of 800 seeds each. However, the authors concluded, “all lots achieved a 98 to 99% germination level regardless of the sound treatment.” I will read this article more carefully tonight. You should read this article also because the description of the experimental design is very good.

http://www.plantphysiol.org/cgi/reprint/53/4/641

The 4th website with one of its references is interesting also, published in the Journal of Botany and is a review paper on the perception of mechanical stimuli of plants. I don’t see any report about experiments on talking to plants, but I’ll read this article more carefully to see if there’s anything you can use.

http://www.amjbot.org/cgi/content/abstract/93/10/1466


Donna Hardy

Thank you Donna!!!

My mom went to the library and found me a book called The Sound of Music and Plants.It talks of how plants are affected by sound waves. I will be posting more about the book soon after I get a little further into it.

Thank you for your help,
Kelsey

Hi Kelsey,

This sounds promising. When you get the book, look at the conclusions and see if they are supported by results of any controlled experiments. See if there are any references that were reported in botanical scientific journals, or if the results were based on the author's individual observations.

Here is a description of a peer-reviewed journal. If an author publishes in a journal like this, the paper will present results of a controlled experiment, or will be a review of lots of papers on a topic; these journal articles are accepted by other scientists as being scientifically valid. Publications in journals that are not peer-reviewed are generally not considered valid. Look at the references you have found and let me know what you think.

http://www.lib.utexas.edu/lsl/help/modules/peer.html

Donna Hardy

Dear Donna,

Thank you for the help with websites. It is going to make the project a lot easier in the long run.

Kelsey

In a section of the book (The Sound of Music and Plants) the section called INTERPRETATIONS AND CONCLUSIONS states that; "Within the limitations of the experiment as described, and with the limits of the small number of plants, it appears that growing plants respond both toward and away from contrasting sound energies introduced into their environments."

I'm not really comprehending what this means. Does it mean that plants do respond to talking? If so, how do I put this in my research and how do I state it? Should I put it into my own words or just state it as it is?

Thanks,
Kelsey

Is this good research?


Dorothy Retallack experimented with plants. She had two groups. Each group consisted of five plants. One group had rock music played in its room. The other group had semi-pop music playing in their room. Retallack found on the ninth day of her observation that about 80% of the stems, leaves, and blooms in the semi-pop room were leaning toward the radio. While the plants in the rock room seemed confused and were bending strangely. Growth had stopped and the leaves begun to yellow.

Please let me know by 1-19-11

Hi Kelsey,

I really admire your meticulous, thorough approach to preparing for your science fair project. And you are asking some really good questions. Here are some questions I would ask about the book you read:

Did Dorothy Retallack measure anything?
Did she organize results in a table or graph?
Did she repeat her experiment more than one time?
How many plants were in each test group?
Were all parameters controlled except for the sound?
Did she include a control group that was not exposed to sound?
Was the radio in the semi-pop room close to a window, so the plants were also leaning towards the light?
Did she forget to water the plants in the rock room?
Has anyone ever been able to reproduce her results?
Was this book located in the fiction or nonfiction section of the library?

The author's conclusion, "it appears that growing plants respond both toward and away from contrasting sound energies introduced into their environments," implies that she thinks that her experiment proved that plants do respond to sound. However, if she did not use the scientific method and control all parameters, except for the sound, then a scientist would be skeptical. What do you think?

I read the paper from the 1974 Plant Physiology by Gaylord Hageseth (a peer-reviewed scientific journal). The author measured the effect of ultrasound on the germination of turnip seeds and used 5000 seeds per test group, repeated his experiment several times, and built special rooms so that each group of seeds, exposed to 1000, 2000, 4000, and 9000 Hz were not exposed to the ultrasound frequency of other groups. He included a control group that was not exposed to ultrasound. He checked for germination every hour during the experiment. Although his results did not meet the usual 95% confidence levels generally expected by scientists (80%), he did show a slight effect of the ultrasound on the rate of germination, although the final germination rate was identical for all groups.

The 2006 review article by Frank W. Telewski titled "A unified Hypothesis of Mechanoperception in Plants," from American Journal of Botany is very interesting also. In this paper, the author reviews the topic of mechanoperception in plants. He reviews the literature for the effects of gravity, compressive force, touch, wind, waves and sound on plant growth. Here are the author's statements about sound, based on a review of the current scientific literature from the top of page 1469, left column, "the level of sound energy normally experienced by plants in the environment does not appear to invoke a significant compromising mechanical stress to plant structure." In other words, plants don't have a measurable response to sound. The authors also state, "the perception and response of plant to sound has been a part of folklore and the source of inspiration for countless primary and secondary school student science fair projects beginning in the 1940's." The author next describes some articles that studied, but found no effect of sound on plants. He then includes references to some articles by Weinberger from the late 1960's and early 1970's et. al. that did show that sound can influence plant growth. Please let me know what you think about this review article.

You have done an outstanding job of finding scientific references on your topic!

I think you are ready to design your experiment; however, this would be a good time to restate your question and propose your hypothesis before you continue. What is the question that you will answer with a carefully controlled experiment? What do you think will happen?

One more comment about experimental design. I am concerned about your idea of using only one plant in each test group. I would recommend using at least 5 plants of each type, if at all possible. Or, perhaps you could study germination of seeds, since that would allow you include more replicates in each test group. Here are some helpful links for designing your project from the Science Buddies website:

https://www.sciencebuddies.org/science- ... bles.shtml

https://www.sciencebuddies.org/science- ... esis.shtml

https://www.sciencebuddies.org/science- ... dure.shtml


Donna Hardy

Kelsey,

Here is a reference you can use in your bibliography I am attaching a reference I found, which was publishing in a scientific journal, Ultrasonics, reported by researchers from Korea and China and published in 2003. The researchers worked in greenhouses and exposed Chinese cabbage and cucumbers to 20 kHz ultrasound for 3 hours a day. They found a statistical significant difference in the levels of polyamine, oxygen consumption, and resistance to insect attack between plants exposed to sound and a control group not exposed to sound.

The authors do not describe how the conditions were controlled and do not report the method for measuring polyamines or oxygen intake. Also, they did not repeat their results. No data is presented regarding insect attacks, even though this information is included in the conclusion. However, they did use a valid statistical analysis method to show there was a difference between the plants exposed to sound and those not exposed to sound. The authors concluded that the Chinese cabbage is significantly affected by ultrasound, but there was not enough data to show the exact relationship between polyamines and oxygen uptake.

If I had been the reviewer on this paper, I would not have accepted it without detailed methods and a description of the control and I would have asked for data on the insect control. I question the validity of the results. However, the paper was apparently reviewed and was published in a scientific journal, so you can use it in your bibliography.

I have a suggestion on your experiment. One of the problems in this field is that results are not reproducible. I think it would be interesting if you could reproduce the methods used in one of the published papers and see if you could obtain the same results. You could pick any of the experiments and set them up as closely as possible to the original report. This experiment would probably be worth doing.

Please let me know if you have any questions about my suggestions.

Donna Hardy

Thank you Donna,
Donna thank you for helping me get more resources. What is the scietific method? I knew it but I forgot the order.
Kelsey

Hi Kelsey,

You are actually going through the scientific method with your approach to your science project. Here is a summary of the Scientific Method from the Science Buddies Website:

o Do Background Research
o Construct a Hypothesis
o Test Your Hypothesis by Doing an Experiment
o Analyze Your Data and Draw a Conclusion
o Communicate Your Results
I recommend that you read through the all of the details of each of these steps before proceeding:

http://sciencebuddies.com/science-fair- ... ndex.shtml

What you are doing now is doing background research to find what everyone has done before in your topic. While doing this, you should be thinking about your experiment and what question you would ask to answer a question that no one has asked before. To answer the question you would design an experiment where all conditions are controlled, except for one parameter, which would be the independent variable. For your experiment, the independent variable would be sound, and your results, or dependent variable would be something that you could measure.

What you have discovered is that this particular topic is not really suitable for a Science Fair project. The effect of sound on plants has been researched, but not confirmed by controlled experiments. No one has been able to reproduce published reports that show an effect of sound on plant growth. The one article that I sent to you yesterday did not describe the controls or even the methods used to measure results. The entire subject has been discredited by the scientific community and described as “folklore,” in a credible scientific journal. Have you told your teacher that your background research has shown that this is not a good topic for a science project?

It will unfortunate if you can’t change topics, but if you must proceed, you should do so as scientifically as possible. Your experiment should be described in detail so someone else could set up your method and obtain the same results. You should use defined wavelengths of sound and the measure time of exposure. You should include a control group of plants not exposed to sound. You should measure the growth or biochemistry of the plants to show a difference in response. All other conditions such as plant type, plant age, water, light, water, soil, and temperature will be the same; the only difference in the plants should be the exposure to sound. You would set up your experiment at least two times.

One possible experiment would be to reproduce Dorothy Retallack’s observations, but this time, control all of the other parameters. That experiment might be worth doing.

So, what do you think you will do?

Donna Hardy

This is my report so far:


Question: Does talking to plants affect their growth?

Research: Dorothy Retallack experimented with plants. She had two groups. Each group consisted of five plants. One group had rock music played in its room. The other group had semi-pop music playing in their room. Retallack found on the ninth day of her observation that about 80% of the stems, leaves, and blooms in the semi-pop room were leaning toward the radio. While the plants in the rock room seemed confused and were bending strangely. Growth had stopped and the leaves begun to yellow.

In nature, plants respond to movement created by wind and rain. They respond by strengthening themselves to withstand these forces of nature. Plants grown in the absence of wind will be weak and spindly. Wind and sound are a wave or they make a wave. These waves are simply formed by areas of higher and lower pressure in the atmosphere through which they travel. For a plant to respond to sound it would have to exist in a place that had lots of noise and no wind.

Work Cited:
Retallack, Dorothy. "Development." The Sound of Music and Plants. Marina Del Rey: DeVORSS &, 1973. 1-93. Web.
Pierce, Gary. "Harnett County: August 1, 2008 - Ask The Hort Agent." Welcome to Harnett County, North Carolina. Web. 9 Jan. 2011. <http://www.harnett.org/coop/august-1-20 ... -agent.asp>.


Hypothesis: If Dorothy Ratallack's experiment was proven true and the plants moved towards and away from the source, then the group I'm nice to will grow, the group I don't talk to will grow normally, and the group I'm mean to will not grow as well because plants respond to wind and sound waves.


Procedure: 1. Make three groups. Each group containing the same three plants.
2. Cut the plants to all equal the same heights and lengths.
3. Label the groups. Nice group, silent group, Mean group
4. Talk and water plants daily. Record observations every other day. Give 1 cup of water to each plant.



Test: My independent variable is the way I talk to the plants.
My dependent variable is the height or growth of the plants.
My constant variable is how much water and light the plants get.

My teacher said I was missing a few things but when I asked him what he wasn't very specific and barely said anything at all.

I feel like the resarch needs a little more. My hypothesis may need some work.


Any suggestions. The suggestion box is the post reply.

All I need to do now is talk to plants for a little less than a month and then do my data, analysis, and conclusion.


Kelsey

Hi Kelsey,

It sounds like your teacher is very busy. Here are some comments that will help your project:

You have made a very good start here with the description of Dorothy Retallak’s experiment. However, you might want to add the scientific references that showed that sound does not have an effect on plant growth and point out the fact that no one has ever been able to reproduce Dorothy’s results. This would add some interest to the topic and you could suggest that your experiment is designed to resolve the long-standing controversy on this topic. Please let me know if you did not understand the additional references I posted and I will explain more.

Also, your experimental design is not like Dorothy’s experiments and you don’t have enough plants in each group to obtain significant results. You need to explain how you will control all of the other parameters, and you need to explain how you will measure the amount of sound that each group is exposed to, and how you will keep the control group from hearing what is going on with the experimental groups. Also, you need to describe how you will measure your results.

Your hypothesis should state something like: I think that plants that are exposed to the key of F for 3 hours a day will grow significantly better than plants exposed to no sound and that plants exposed to the key of F for 8 hours a day will not grow as well as plants exposed to no sound.

The subjects of the effect of wind and rain on plants is a different topic and is not related to the effect of sound, so you should not mention these topics unless you add a review paragraph about all of the physical forces that affect plant growth.

Donna Hardy

Hi,

Here is information that will help you improve your experimental protocol:

When doing a scientific investigation, you want to provide enough detail so that someone reading your experiment can reproduce your results. So you need to add some precision and details to your protocol

Your independent variable is the sound. Your control group will be exposed to nothing except ambient sound. Your two experimental groups will be exposed to other sounds, and it will be helpful if you can define that sound.

Sounds are measured by their frequency. Please go to this website and listen to the various sounds:

http://en.wikipedia.org/wiki/Audio_frequency

Do you have some way of measuring the frequency of your voice? Do you have some way of recording your voice so it can be played back for the plants?

In Dorothy Retallack’s original experiment, she reported optimum results with a 3-hour exposure time. The Chinese researchers who also reported significant results also used a 3-hour time. Are you going to talk for 3 hours to each group? If not, can you record your voice and play it for 3 hours a day to each group of plants? Do you need to use a different time period? If, you need to define the time and repeat the same sound pattern every day of your experiment. Please think about this and decide how you can define the frequency of the sound and the time of exposure for each group of plants.

Dorothy Retallack used separate soundproof chambers. The Chinese researchers used separate greenhouses with loud speakers. How are your going to separate your groups of plants so they are not exposed to the other groups’ sounds? This is tricky, because all other growing conditions must be controlled. If you are doing this project at home, can you use grow lights and devise some sort of soundproof chamber to keep the groups of plants isolated from each other?

Dorothy Retallack used groups of 5 plants. The Chinese researchers used a whole greenhouse full of plants, but did not specify an exact number. The researcher who studied seed germination used 500 seeds in each group. You should use at least 5 plants of a single variety and plan to repeat the experiment at least one time (experiments can be run concurrently). The reason for the larger number of plants is that when you obtain results, you will be able to calculate the difference in results.

All other parameters must be controlled, and you should define the conditions. It will be helpful if you can describe the following:

1. Name of plant (genus and species name preferred).
2. Type of soil used.
3. Size of pot in centimeters (metric measurements preferred for science projects).
4. Light intensity. If you can borrow grow lights for this project, you can define the light intensity, time of light, and distance of plants from the light. If you will be using natural light, see if you can borrow a light meter and measure the light intensity and record the hours of sunlight each day.
5. Moisture. You need to keep your plants watered consistently and you should describe how you keep the plants watered. Most plants do best if the pots are allowed to dry out almost completely in between watering.
6. Temperature. If you are using ambient temperature, it would be helpful if you could record the temperature in degrees Centigrade at least once a day to verify that the 3 groups of plants were grown in the same temperature.
7. Fertilizer: If you do fertilize the plants during the experiment state what brand of fertilizer you used and how much fertilizer you used.

I hope this helps. Do you want to try rewriting your protocol? I do not know what resources you have available to do your project, so you will have to define each of the parameters that I have described depending on what you can actually do. Let me know if you have any questions.

Donna Hardy

Hi,

This is a continuation of suggestions for your procedure section. You need to describe how you are going to record and measure your results. Having some quantitative results is essential and will give you some data for analysis. Here is the information again from the Science Buddies website on measuring plant growth:

https://www.sciencebuddies.org/science- ... owth.shtml

Since you will be continuing your experiment over time, you don’t want to do any of the destructive measurements, so you should pick one or more of the other methods. You have a choice of the following, and it would be good if you could do all three methods.

1. plant height in centimeters
2. counting number of leaves
3. measuring area of leaves

You should plan to do a set of measurements every 2-3 days and continue the experiment for as long as possible. The data points over time will give you results that you can graph and present in your results section.

What type of plants are your working with?

In addition, you should plan to make general observations on your plants every day or two. You should write down a description of the plants and note any changes such as leaning toward the source of the sound, yellowing of leaves, wilting, etc.

Do you have a bound lab notebook to record your results in as you go along? I highly recommend this as it will be very helpful to have all of your data together when you are ready to write up your results. You will want to include the lab notebook with your display board. It should be neat, but doesn’t have to be perfect. If you make a mistake, just cross out the error with one line and continue. Use a blue or black ink pen to record your results.

You should be able to write both your materials and methods (procedure) sections now. Please let me know if you have any questions. I want your science fair project to be outstanding!

Donna Hardy

Dear Donna,

I do have a journal for this project. I write in it every other day. My observations have only lasted for a couple weeks so I expect them to change a little very soon. If I need anymore help you know I will be on right away.

Kelsey

Dear Donna,
My project was great. My grade was a 96 and I won first place for Botany and third place for grand champion. I was tied for third place but the teachers said that the judges claimed my journal put me ahead. Now there is another science fair at a college near us and all winners are allowed to enter it. The other two grand champions are going and everyone (teachers) wants me to do it to. So my science teacher would like for me to continue work on the project and enter it in March.

Thanks for your help,
Kelsey

Hi Kelsey,

Congratulations! You did an excellent job, and I'm sure your scientific approach made the difference in winning. There will be more competition at the next level so it would be good to do some additional work. How much time do you have? Do you have time to do another experiment? Frequently judges will make comments on projects that they think will be going to the next level of competition. Did any of your judges make any comments? What comments did you teacher make? If you don't have time to do another experiment, you should respond to any comments. Let me know what I can do to help.

Donna Hardy

Dear Donna,

I first want to thank you because without your help I would have been lost. And secondly I agree that the high grade and good placing was because of the work I put into the scientific method. I am not sure what comments the judges made because the fair was just a leave the project there and they looked at them without us there.

My teacher seems tomake a point that my procedure needs to be clearer, which is, "Procedure: 1. Make three groups. Each group containing the same three plants. 2. Cut the plants to the same heights and lengths. Plant seedlings. 3. Label the groups. A, B, and C. Talk nicely to A, be angry or mean towards B, and don’t talk to C. 4. Talk to plants daily. Record observations every three days. 5. Give ½ cup of water to each plant every three days. Except for the seedlings which get a half cup until they sprout, when they sprout they then get five tablespoons every other day and are moved to plastic cups." How can i make this a clearer statment?

I began adding more work to this project March 1st. This needs to really be done before the 18th of march because the fair is on the 19th. So wish me luck!!

Thanks,
Kelsey

Hi Kelsey,

What your teacher is trying to tell you is that you need to rewrite your protocol so that someone who is reading your protocol can do exactly what you did. So you would say that you used 3 plants (include genus and species) growing in x-centimeter diameter pots, and cut them y-centimeters high, and placed them in an environment with z-number of hours of light per day at 22 degrees Centigrade, etc. The description of the amount of watering you gave is very good, but use metric measurements since this is a science project. Be specific with your details of your plants and how you handled them. The problem will be describing your independent variable because you need a quantitative way of measuring your voice. Do you have any way of quantitatively measuring your voice? This is going to require some creativity. I will try to think of something you can do.

Will the next science fair include interviews by the judges?

Donna Hardy