The purpose of this experiment was to find out what colored light bulb
would increase the growth rate of string bean plants the most after eighteen
days of growing under a colored light bulb.
I became interested in this idea when I was looking for an idea for
a project and I came across this one more that once. Then I thought
it would be an interesting experiment to conduct.
The information gained by this experiment will benefit society by,
if farmers that grow beans indoors want to speed up the growth rate, they
can see which color of light bulb will make beans grow the fastest.
My hypothesis is that the red light bulb will increase the growth rate
of string bean plants more that the clear, blue, and yellow light bulbs
I base my hypothesis on the fact that, "When used alone, red light
will make plants grow tall and spindly," stated in an article on the internet
called "House Plants-Artificial light."
The constants in this study were:
The manipulative variable was the color of light that each plant was exposed
to. The four groups of six will each receive a different color of
light. Group A will be exposed to a red light bulb, and group B will
be exposed to a blue colored light bulb. The group C will receive
a yellow light while D receives the light from a plain light bulb.
The type of bean seed
Amount of soil in each cup
Amount of water that each plant gets
The amount of light that each plant is exposed to
The temperature of the plants surroundings
The depth in witch each seed is planted
Same size and width of the cups
The responding variable is the height of the string bean plants after
18 days of growing. To measure the growth of the string beans you
would take a ruler and set it on the soil and measure to the highest point
of the plant and record the height.
||string bean seeds
|| colored light bulbs (red, yellow, blue and clear)
||trays or tubs to set plants in
||250 ml Styrofoam cups
|| poking pencil
||pieces of tape for labeling
||4680ml purified water
||3900ml seed starting potting soil
1. Gather materials and carefully poke three holes in the bottom of
each of the 26 cups with a pencil for water drainage.
2. Use the measuring cup and put 100ml of seed starting potting soil
in each Styrofoam cup.
3. Then place a string bean seed in the center of each cup and fill
the cup with 50 more ml of soil.
4. After that, sprinkle 5ml of purified water in each cup and divide
the 26 cups into four groups of six.
5. Set each group of cups into different water trays and label the
cups A1, A2, B1, B2 and so on, then label the trays A-red, B-blue, C-yellow,
6. Put a sheet of plastic wrap over each tray and place in the compartment
of the grow box that bulb matches the label (donít turn the light on).
7. Let the trays sit in the grow box with the cover down until the
plants start to germinate and you can see the seeds sprouting.
8. Then you turn the light on at 7:00 in the morning and turn it off
at 10:00 at night every day for 18 days.
9. But at 3:00 each day you need to measure each plant by setting
the ruler vertically at the base of the soil and measure to the highest
point of the plant.
10. Then record your data. Measure each plant everyday at around
the same time.
11. Also, everyday you need to sprinkle 5ml of purified water on each
12. At the end of the eighteen days you can throw the plants away and
clean out the grow box and the materials.
13. To find the average growth of the plants you would add together
the highest height of all the plants in one group and divide by six to
find the average growth.
14. Find the average to all groups and find out which color of light
bulb works the best.
The original purpose of this experiment was to determine which colored
light bulb would increase the growth rate of string beans the most after
eighteen days of growing.
The results of this experiment were that the plants growing
under the clear light bulb grew the highest out of the plants under the
red, blue and yellow light bulb. The average growth for the clear
light bulb was 32cm, the yellow came in second with 28cm and the red got
third place with an average of 23cm. The plants under the blue colored
light bulb grew the least; the average for the blue was 17cm. Therefore,
the best light bulb to use is the clear light bulb.
See my table and graph.
My hypothesis was that was that the red light bulb will increase the
growth rate of string bean plants more than the blue, yellow, and clear
light bulb will. The results indicate that my hypothesis should be
rejected. The plants growing under the clear light bulb grew the
highest, not the ones under the red.
Because of the results of this experiment, I wonder if the clear light
bulb made the plants grows the highest because it is the color closeted
to natural sunlight. My findings should be useful to farmers who
plant beans indoors, because they now know to use a clear light bulb.
If I were to conduct this experiment again, I would use more colors of
light bulbs and more bean plants.
Have you ever wondered if you could grow string beans under a
different light source rather than the sun? Like maybe a plane incantation
light bulb or a colored incantation bulb? Well I did, so I decided
to do a science project on it and write a research report. I found
out about the wavelengths of colored light and about artificial light.
A topic that interested me was about the history of string bean plants.
I also learned about photosynthesis and germination. Another topic
that I researched was about plant cells. I then put all of my research
together into one big research report.
I painted the "grow box" the color white so that the light would
reflect off of the white walls and go back into the plant. Reflection
is a line that is like a ray of light. Reflection is when light rays
bounce off the walls, like in my box, it is all painted white so the light
rays bounce off of the walls and keep doing so until it hits something
that will absorb it, like a plant. An example of reflection are that
when you look into a mirror or a body of water when the sun is shining
or the light is on, the light rays bounce off of the mirror or water into
your eyes so you see your reflection. Reflection is a very useful
tool in growing plants indorse for more light.
A plant, like string beans, is made up of thousands of tiny little
microscopic plant cells. A plant cell consists of eleven different
major parts. They are; cell wall, cell membrane, Golgi body, nuclear
membrane, nucleus, ribosome, cataclysmic residuum, cytoplasm, mitochondrion,
vacuole, and chloroplast. The nucleus is the control center for the
whole cell, most cells have a nucleus. Outside of the nucleus there
is the nuclear membrane. A nuclear membrane is very thin, cells have
one so it can block of the rest of the cell from the nucleus. A cell
wall is kind of like the nuclear membrane but it is stiff and it supports
the cell. It is like the nuclear membrane because, they both are
walls that surround and protect something. A cell membrane is made
up of proteins and lipids; it surrounds the cytoplasm and nucleus.
Cytoplasm is a goo substance that all of the livings materials are made
of accept the nucleus. The rest of the plant cells are made up of
organelles. The organelle that creates and transfers materials to
one place to another is called a golgi body. An endoplasmic reticule
is an organelle that does almost the same thing as the Golgi bodi.
It transfers materials from one place to another. Another organelle
is called ribosome; it makes and gives protein to the cell. Chloroplast
is an organelle that all it does is hold chlorophyll inside the cell.
The last two organelles inside a cell are vacuole and mitochondrion.
Vacuole stores food, water, and wastes, it also disposes of the wastes
that it stores. Mitochondrion is like the powerhouse of the whole
cell it provides it with all of its energy. All of those things are
what makes up a plant cell.
String beans are probably one of the most popular vegetables throughout
the world, but there are some things that you need to know if you are going
to grow them. People first found out that you can eat string beans
and they actually tastes good, when a long time ago a cook was making a
soup and one of the beans from his plant fell into the soup, before he
realized that it was their he had already served it and the people noticed
how good they were. String beans are quite healthy; 250ml of string
beans have about 30 calories. They have lots of calcium, potassium,
phosphorous, and tons of vitamin A. There are many diseases that
string beans can get, but thankfully there are easy ways to tell if your
beans have them. Some diseases are; anthracnose blights, damping
off, and rot. To tell if your bean has anthracnose it will ooze a
pinkish liquid. Blights, you can tell if there are watery spots on
parts of the plants foliage, and damping off, the bottom of the stem will
become very mushy (this is common in starting seeds). If you shake
or perhaps drop a bag of seeds, it can damage them and cause your plants
to mature slower or not at all. Remember all of these things when
planting string beans, and donít forget that they are yummy and healthy
Colored Light and Wavelength
Colored light and wavelengths are an important part of my project,
and the facts about them are very useful to know. The different dencity
in the different colors causes different colored lights to have different
wavelengths. The colors that wavelengths are four hundred nanometers
are the lighter and more dense colors like violet, indigo, and blue.
Then there is the colors that are a little bright like green and yellow,
those are five hundred nanometers. The colored lights that are six
hundred nanometers are more bright colors like orange and red. Colors
that donít have a high wavelength have a high level of energy to grow.
Science Insights/Wesley Addison/Plant Cells
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