plant light color experiment

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Level of Education

• Post Secondary

Recommended Age

Time Required

• ~10 minutes
• ~20 minutes
• ~30 minutes
• ~45 minutes

1 day or more

Number of people

• 100 – 200 €

Supervision

Does different coloured light have an effect on plant growth?

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Learning Objectives

The learning objectives of the following experiment include: – Investigating the effects of different coloured lights on plant growth. – Observing whether any specific colours of light encourage more growth compared to other colours, or whether they have no influence at all.

Photosynthesis

Photosynthesis is the process by which light energy is converted into chemical energy. This can be represented by the following equation: 6 CO2 + 6 H2O → C6H12O6 + 6 O2

The distance between two consecutive waves (i.e. from peak to peak or trough to trough).

Chlorophyll

Green pigment found in plants that helps the process of photosynthesis.

Carotenoids

Pigment used for photosynthesis that allows the absorption of light at specific wavelengths.

Start off the experiment by filling the 5 plastic cups at least ¾ full with soil.

Place your thumb on the surface of the soil present in the cups and press down gently to make a small hole.

Place the seeds in the hole and cover with soil.

Repeat steps 2 and 3 for all the plastic cups containing the soil.

Get the shoe boxes, remove their lids and using the scissors cut out one side of each box.

Cut a hole in the bottom of the shoe box. Make the hole as big as possible without cutting the corners of the box. Pierce 5-10 small holes in the remaining sides of the box.

Now tape the coloured cellophane over the side that has been removed and side and over the hole in the bottom of the box.

Repeat steps 5 and 7 three more times using a different colour cellophane for each shoe box.

It is important to keep one box that is not taped with cellophane to be used as a control.

Place one of the boxes over each cup.

Place the boxes in an area which is well lit such as next to a window, with the opening in the box facing the light.

Water the plant each day for 3-5 weeks (until the plant grows to a sufficient height).

Use the ruler to see which plant grew the tallest. Also take notice of the leaf colours, their size, time taken for the seeds to germinate etc. Act like a detective and note down every observation you make.

If you wish to grow other plants, do so. Using Pea plant seeds would work just as well. However, when choosing a plant make sure that it is easy to grow and that it does not take a long time to germinate, as this would make the experiment last much longer than 3-5 weeks.

When cutting the boxes, adult supervision will be required if the participant is in the 6 – 9 year old category.

In case of allergies to beans participants can easily grow other plants instead and conduct the experiment as instructed in the procedure.

Imagine you are wanting to produce the best bean plants possible in time for your local harvest festival. You’ve noticed that your biggest competitor is using lamps with an orange tinge to grow their beans and you are wondering why. You devise an experiment using multiple coloured filters in order to work out which colour of light is best and win the competition.

Which light colour caused the greatest plant growth? Red and blue light, colours which are furthest away from green in the light spectrum.

Name a pigment that absorbs light. Chlorophyll, carotene.

What is the function of chlorophyll? Converts light energy into chemical energy which the plant can use.

What colour filter will be/was the most detrimental towards plant growth? Green since it is reflected rather than absorbed by the plant.

Why are plants green? Chlorophyll reflects green light and absorbs all other light.

Why are carrots orange? Carotene reflects orange light and absorbs all other light.

The objective of this experiment is to show that plants react differently to different colours. Plants need light for the process of photosynthesis. In other words, plants use light to produce the necessary nutrients needed for plant growth.

White light contains a spectrum of colours which make up the colours of the rainbow: red, orange, yellow, green, blue, indigo and violet. This is why when you pass white light through a prism, the ray of light splits up to reveal these colours.

Plants and other materials show the colour they themselves reflect. Therefore if a plant appears green to our eyes then we know it is reflecting most of the green wavelengths of light and not absorbing them. Therefore, it should not surprise us that the plants exposed to green light would have grown the least compared to plants that were grown under different colours. The pigment responsible for the plant’s green colour is chlorophyll, reflecting most of the green light back, and strongly absorbing the light of other colours in the spectrum e.g red and blue wavelengths. Effect of light Colours on Bean Plant Growth. Why are Plants Green?

In this experiment it was shown that different wavelengths of light are responsible for the different growth responses. This is because the plant leaf cells possess chlorophylls and carotenoids, organelles which can only absorb specific wavelengths of light, as detailed in the following absorption spectrum:

The following diagram shows the corresponding wavelengths of the colours.

As you can see, both the maximum light absorbance for chlorophyll a and chlorophyll b occurs in the range of light wavelengths that produce either blue or red light. Carotenoids absorb some of the light from the blue/green region, increasing the range of wavelengths of light that can be absorbed by the plant. Plants need to absorb light as part of the process of converting carbon dioxide and water into glucose through the biochemical process of photosynthesis. This glucose can then be used by the plant to respire and create ATP, a form of energy which can be used for biological processes such as growth and repair.

Carotenoids are accessory pigments since they cannot perform photosynthesis, but have to pass the energy obtained from light to chlorophyll.

In the middle of the absorption spectrum there seems to be almost no absorption of light which explains why the green colour was responsible for a lower amount of growth when compared to other filter colours.

Applications

Hydroponics is a method which allows the growing of plants without the use of soil but instead using water containing the necessary nutrients. In hydroponics, multi-colour LEDs can be used which offer any spectrum of light to maximise plant growth. http://www.epicgardening.com/types-of-hydroponic-lighting/

An interesting new method to measure the rate of photosynthesis in aquatic plants using acoustic analysis. By measuring the sound produced by the formation of gas bubbles during photosynthesis can be measured and allows more accurate measurement of photosynthetic processes in hydrophytic plants than using a photosynthometers. http://www.nature.com/articles/srep44526

Biofuel cells are an innovative means of transforming the chemical energy generated by the process of photosynthesis into electrical energy. This allows the production of electrical energy without the need of fossil fuels. https://www.sciencedaily.com/releases/2010/02/100218092846.htm

The concept of using different colours to enhance plant growth is also used in greenhouses. Using different coloured plastic films, the colour of light reaching the plants can be controlled.

Be creative and try the experiment with different plant seeds. See if the same results are obtained.

You could also try out this experiment during different seasons, which may influence plant growth due to factors such as air temperature and humidity. Try the experiment in summer and in winter and compare results.

Preparation: 1 hour

Conducting: 3-5 weeks

Clean Up: 10 minutes

Number of People

4 participants

Not Required

Different coloured cellophane, around 4 will do (such as green, red, blue, yellow, violet) 5 plastic cups 5 shoe boxes 5 bean plant seeds or any other type of plant seeds that are easy to grow. Soil Water Ruler Tape Scissors

Contributors

Can coloured lights affect how plants grow

Effect of Light Colours on Bean Plant Growth

Photosynthetic Pigments

Chlorophyll absorption and photosynthetic action spectra

Does the colour of light affect the rate of plant growth

Experiment: Red Light vs Blue Light -How Spectrums Affect Plant Growth- LED vs CFL

Photosynthesis: Crash Course Biology

Photosynthesis: Action vs Absorption

Additional Content

10 Facts on Photosynthesis  (Beginner)

Photosynthesis: How Plants Make Food and Energy?  (Beginner)

A Big Leap for an Artificial Leaf  (Intermediate)

Photosynthesis: A new source of electrical energy? Biofuel cell works in cactus  (Intermediate)

Is artificial photosynthesis the next big thing in alternative energy?  (Advanced)

Cite this Experiment

Aquilina, M. C., Styles, C., Ghirxi, D., & Wootton , B. (2020, August 03). Does different coloured light have an effect on plant growth?. Retrieved from http://steamexperiments.com/experiment/does-different-coloured-light-have-an-effect-on-plant-growth/

First published: August 3, 2020 Last modified: August 26, 2020

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Make a hypothesis about which color in the visible spectrum causes the most plant growth and which color in the visible spectrum causes the least plant growth.

How did you test your hypothesis? Which variables did you control in your experiment and which variable did you change in order to compare your growth results?

Analyze the results of your experiment. Did your data support your hypothesis? Explain. If you conducted tests with more than one type of seed, explain any differences or similarities you found among the types of seeds.

What conclusions can you draw about which color in the visible spectrum causes the most plant growth?

Given that white light contains all colors of the spectrum, what growth results would you expect under white light?

• Carry out an experiment to determine which colors of the light spectrum are used in photosynthesis as evidenced by plant growth.
• Measure plant growth under lights of different colors of the spectrum.

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Science project, does the color of light affect plant growth.

Grade Level: 4th - 7th; Type: Life Science

To determine if the color of light affects the growth of plants.

This experiment attempts to discover whether the color of the greenhouse material impacts the growth of the seedlings inside.

Research Questions:

• What colors of light do plants need in order to gather energy from sunlight?
• Why are greenhouses green?
• What is full spectrum light?
• Which colors of filters block ultraviolet light?
• How to plants convert sunlight into energy?
• How do plants use chlorophyll?

Plants are commonly grown in greenhouses, which provide extra warmth and humidity by forming a barrier between young plants and the outside environment. This allows plants to thrive when outdoor conditions would be too harsh for them.  Though greenhouses are classically built out of clear glass or plastic, there are some built from semi-porous netting. The term greenhouse does not just apply to structures that are green, though many greenhouses are covered in green, semi-transparent plastic. Plants require sunlight to grow, which they transform into usable energy in their chlorophyll. This experiment attempts to discover whether the chlorophyll in plants can transform light into energy when certain colors of light are missing from the spectrum.

• 50 1 foot long pieces of 1x1 wood
• Green cellophane
• Blue cellophane
• Clear cellophane
• Yellow cellophane
• Red cellophane
• glue or tape
• Potting soil
• Planting containers (smaller than 1’ by 1’)
• Marigold seeds

Most of these materials will be easy to find at a hardware store. An adult can help saw the wood into 1 foot long pieces for you to use or the hardware store can do it for you. If your local hardware store doesn’t carry colored cellophane, you can try looking at an arts and crafts store.

Experimental Procedure :

• After gathering all the necessary materials, you will need to construct your miniature greenhouses. Start by separating the foot-long pieces of 1”x1” boards into groups of 10. You will need 10 pieces to construct each greenhouse.
• Use two nails to attach the wood together at each corner.
• Once you have built five greenhouse frames, you are ready to add the greenhouse covers. Cut out pieces of colored cellophane large enough to cover the sides of the greenhouse frames.
• Attach the colored cellophane to the frames using tape or glue, making sure that each greenhouse is covered in a different color. Do not cover the bottom of the frames.
• One greenhouse will need to be covered in clear cellophane. This will be your control.
• Fill the potting trays with soil.
• Plant the seeds according to the package instructions.
• Water the seedlings daily and record results on a growth chart such as the ones below. Monitor the experiment for at least two weeks.

Terms/Concepts: Chlorophyll; Full spectrum; Natural light;  Light filter; Germinate; Greenhouse design

References:

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Do Different Colors of Light Affect Plant Growth?

Students, even when they are in high school and college, enjoy planting seeds and watching plants grow from them.

From a teaching perspective, a wonderful thing about growing plants is they give so many opportunities for students to use the scientific method to develop and test hypotheses.

It is a generally accepted principle that visible light supports maximal photosynthesis in green plants. Wavelengths of life between 610 and 700 nanometers, supplemented by blue and green light, is optimal for germination, bud development, flowering, and plant growth.

Different wavelengths of light, however, have specialized effects in plants that your students can easily test.

How Different Colors of Light Affect Plant Growth

Consider these statements about how different colors of light affect plant growth—which your students can formulate as testable hypotheses and then test with simple experiments:

The color of light affects plant growth, but the effect of color is more noticeable in low-intensity light, for example, growing plants under the glazed glass windows of a greenhouse or on the windowsill at home or in a classroom.

• Rates of photosynthesis increase under blue and red light, but blue and yellow light have little effect.
• Blue light increases the production of chlorophyll in seedlings.
• Some seedlings can’t sprout without exposure to blue light.
• Red light increases flowering and fruiting.
• The amount of light to which a fruiting plant is exposed affects the sugar content, tartness, and size of its fruit.

Students who have a suitable math background can explore the concept of the daily light integral, known in horticulture as the DLI. They can test hypotheses about the relationship of the DLI to plant growth. They can test the relationship of the DLI to plant growth when certain wavelengths of light are enhanced or excluded.

And your students can test hypotheses that UV light may be harmful to plants, but violet light may stimulate all stages of growth. They can test their hypotheses that blue light is helpful only in the earliest stages of growth, or whether it may be helpful at all stages of growth.

Students can test the idea that yellow light doesn’t stimulate the production of chlorophyll, but plants that are grown under yellow light are healthier. They can test their hypothesis that red light makes flowers bloom.

Use experiments to Help Your Students

Experiments involving the effects of specific spectra of visible and UV light have different effects on plant growth are easy to set up on your own, but they are even easier with Modern Biology.

With Modern Biology’s IND-32: Plant Pigment/Peroxidase Analysis , your students can even begin to characterize the carotene, anthocyanidin, and lycopene pigments they extract from common fruits and vegetables by comparing them to albumin and cytochrome-C with electrophoresis.

Why choose Modern Biology experiments

Every experiment kit made by Modern Biology supports scientific thinking. Students test their hypotheses. They never just watch demonstrations. They are never limited to facts and vocabulary.

Every Modern Biology helps students develop the manual dexterity and note-taking skills that they will carry to future study and their careers. Modern Biology is developed by working scientists for future working scientists.

Every Modern Biology kit includes all the reagents and test materials teachers need for their laboratory exercise. There is no need to order separate reagents, no fussing about missing shipments, and no checking out lab materials from the supply room.

Modern Biology supplies the safe, non-toxic, reliable reagents and measurement materials you need for every laboratory exercise. And because every Modern Biology experiment is available at a fixed cost, it’s easier to budget your supply cost for each class for each term.

Want to learn more? Email Modern Biology or call us at (765) 446-4220 Monday through Friday from 9 to 5 Eastern time.

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How Does Light Color Affect Plant Growth? (With Examples)

How Does Light Color Affect Plant Growth?

Plants need light to grow, but not all light is created equal. The color of light can have a significant impact on plant growth, development, and productivity. In this article, we will explore how light color affects plants, and discuss the implications for growers and gardeners.

We will begin by discussing the different types of light and how they are perceived by plants. We will then explore the different ways that light color can affect plant growth, including photosynthesis, stem elongation, and flowering. Finally, we will discuss some of the practical applications of this research for growers and gardeners.

By the end of this article, you will have a better understanding of how light color affects plants, and you will be able to make informed decisions about how to light your garden or grow space.

Light is essential for plant growth. It provides the energy that plants need to photosynthesize, the process by which they convert sunlight into chemical energy. The amount of light that a plant receives, as well as the quality of the light, can have a significant impact on its growth and development.

The visible spectrum of light is divided into seven colors: red, orange, yellow, green, blue, indigo, and violet. Each color of light has a different wavelength, and plants absorb different wavelengths of light more effectively than others.

The absorption of light by plants is important because it determines the rate at which photosynthesis can occur. Photosynthesis is the process by which plants use light energy to convert carbon dioxide and water into glucose and oxygen. Glucose is a sugar that plants use as energy, and oxygen is a byproduct of photosynthesis that is released into the atmosphere.

The role of light in photosynthesis is essential for plant growth. Without light, plants would not be able to produce food, and they would eventually die. The amount of light that a plant receives, as well as the quality of the light, can have a significant impact on its growth and development.

The Effects of Light Color on Plant Growth

The color of light can have a significant impact on plant growth. Different colors of light have different wavelengths, and plants absorb different wavelengths of light more effectively than others. The absorption of light by plants is important because it determines the rate at which photosynthesis can occur.

The following table shows the wavelengths of light that are absorbed most effectively by plants:

| Color | Wavelength (nm) | |—|—| | Red | 600-700 | | Blue | 400-500 | | Green | 500-600 | | Yellow | 570-590 | | White | 400-700 |

As you can see from the table, red light is the most effective wavelength for photosynthesis, followed by blue light. Green light is also absorbed by plants, but not as effectively as red or blue light. Yellow and white light are a mixture of red, blue, and green light, so they are also absorbed by plants, but not as effectively as pure red or blue light.

The effects of light color on plant growth can be summarized as follows:

• Red light: Red light is the most effective wavelength for photosynthesis, so it is essential for plant growth. Red light also promotes the development of strong stems and leaves.
• Blue light: Blue light is also important for photosynthesis, but it is not as effective as red light. Blue light helps plants to produce chlorophyll, the green pigment that is responsible for photosynthesis. Blue light also helps plants to develop strong roots.
• Green light: Green light is not as effective for photosynthesis as red or blue light, but it is still absorbed by plants. Green light helps plants to produce carotenoids, the yellow and orange pigments that give plants their color.
• Yellow light: Yellow light is a mixture of red and green light, so it is absorbed by plants in a similar way to red and green light. Yellow light helps plants to produce chlorophyll and carotenoids.
• White light: White light is a mixture of all the colors of the visible spectrum, so it is absorbed by plants in a similar way to red, blue, green, and yellow light. White light helps plants to produce chlorophyll, carotenoids, and strong stems and leaves.

The Different Light Colors and Their Effects on Plant Growth

The different colors of light have different effects on plant growth. The following table summarizes the effects of the different light colors on plant growth:

| Color | Effect on Plant Growth | |—|—| | Red | Promotes the development of strong stems and leaves | | Blue | Helps plants to produce chlorophyll and strong roots | | Green | Helps plants to produce carotenoids | | Yellow | Helps plants to produce chlorophyll and carotenoids | | White | Helps plants to produce chlorophyll, carotenoids, and strong stems and leaves |

It is important to note that the effects of light color on plant growth are not always consistent. The effects of light color can vary depending on the plant species, the stage of plant growth, and the environmental conditions.

For example, some plants require more red light than others. Plants that are grown for their fruits or vegetables often require more red light than plants that are grown for their flowers. Young plants often require more blue light than older plants. And plants that are grown in sunny environments often require less light than plants that are grown in shady environments.

Light color is an important factor that can affect plant growth. The different colors of light have different effects on plant growth, and the effects of light color can vary depending on the plant species, the stage

3. Factors That Affect the Response of Plants to Light Color

The response of plants to light color is affected by a number of factors, including:

• The intensity of light . The intensity of light is measured in lumens. The higher the intensity of light, the more energy is available for photosynthesis. Plants that are grown in high-intensity light will grow faster and produce more biomass than plants that are grown in low-intensity light.
• The duration of light exposure . The duration of light exposure is measured in hours. Plants require a certain amount of light exposure each day in order to grow and develop properly. The amount of light exposure that a plant needs varies depending on the species of the plant.
• The age of the plant . The age of the plant also affects its response to light color. Young seedlings are more sensitive to light color than older plants. This is because young seedlings have not yet developed the pigments that they need to absorb light energy efficiently.
• The species of the plant . The species of the plant also affects its response to light color. Some plants are more sensitive to light color than others. For example, plants that have red or purple leaves are more sensitive to blue light than plants that have green leaves.

4. Applications of the Knowledge of Light Color and Plant Growth

The knowledge of light color and plant growth has a number of applications, including:

• Horticulture . Horticulturists use the knowledge of light color to grow plants in a variety of different environments. For example, they use red light to promote flowering in plants and blue light to promote vegetative growth.
• Agriculture . Farmers use the knowledge of light color to improve crop yields. For example, they use red light to increase the production of tomatoes and blue light to increase the production of wheat.
• Controlled environment agriculture . Controlled environment agriculture (CEA) is a type of agriculture that is practiced in greenhouses or other controlled environments. CEA growers use the knowledge of light color to optimize the growth and development of their crops.
• Space exploration . The knowledge of light color is also being used to develop plants that can be grown in space. These plants will be used to provide food and oxygen for astronauts on long-duration space missions.

The knowledge of light color and plant growth is a valuable tool that can be used to improve the growth and development of plants in a variety of different environments. This knowledge is being used by horticulturists, farmers, CEA growers, and space explorers to improve the quality and quantity of food production.

Q: How does light color affect plant growth?

A: The color of light that a plant receives can have a significant impact on its growth and development. Different colors of light have different wavelengths, and each wavelength carries a different amount of energy. The type of energy that a plant receives determines how it uses that energy for photosynthesis, growth, and other processes.

Q: What are the different colors of light and how do they affect plant growth?

A: The visible light spectrum is made up of the colors red, orange, yellow, green, blue, indigo, and violet. Each color of light has a different wavelength and energy level.

• Red light has the longest wavelength and lowest energy level. It is essential for photosynthesis and plant growth.
• Orange light has a shorter wavelength and higher energy level than red light. It is also important for photosynthesis, but it is not as essential as red light.
• Yellow light has a shorter wavelength and higher energy level than orange light. It is not as important for photosynthesis as red or orange light, but it can help to improve plant growth.
• Green light has the shortest wavelength and highest energy level of all the visible colors. It is not used for photosynthesis, but it can help to protect plants from damage.
• Blue light has a shorter wavelength and higher energy level than green light. It is not used for photosynthesis, but it can help to promote plant growth.
• Indigo light has a shorter wavelength and higher energy level than blue light. It is not used for photosynthesis, and it can be harmful to plants in high doses.
• Violet light has the shortest wavelength and highest energy level of all the visible colors. It is not used for photosynthesis, and it can be harmful to plants in high doses.

Q: How much light do plants need to grow?

A: The amount of light that a plant needs depends on the type of plant. Some plants, such as cacti and succulents, can tolerate low light conditions, while other plants, such as leafy greens and flowering plants, require more light to thrive.

Generally speaking, plants need at least 6 hours of direct sunlight per day to grow properly. However, some plants can tolerate more or less light, depending on their specific needs. If you are not sure how much light a particular plant needs, it is best to err on the side of caution and provide it with more light than less.

Q: How can I provide my plants with the right amount of light?

A: There are a few different ways to provide your plants with the right amount of light.

• Sunlight: If you live in a sunny area, you can simply place your plants outdoors in a spot where they will receive plenty of direct sunlight.
• Artificial light: If you live in a shady area or if you want to grow plants indoors, you can use artificial light to supplement the natural light that is available. There are a variety of different types of artificial lights available, so you can choose one that is best suited for your needs.
• Grow lights: Grow lights are a type of artificial light that is specifically designed for growing plants. They are typically very bright and emit a full spectrum of light, which is ideal for photosynthesis. Grow lights can be used to grow plants indoors or in areas where there is not enough natural light.

Q: What happens if plants don’t get enough light?

A: If plants do not get enough light, they will not be able to photosynthesize properly. This can lead to a variety of problems, including stunted growth, yellowing leaves, and leaf drop. In severe cases, a lack of light can even kill a plant.

Q: What happens if plants get too much light?

A: If plants get too much light, they can also experience problems. Too much light can damage the leaves of a plant, causing them to turn brown or even scorch. In severe cases, too much light can even kill a plant.

Q: How can I tell if my plants are getting too much or too little light?

A: There are a few ways to tell if your plants are getting too much or too little light.

• The leaves of your plants will be a telltale sign. If the leaves are yellowing or turning brown, it is likely that your plants are not

the color of light can have a significant impact on plant growth. Blue light is the most beneficial wavelength for photosynthesis, while red light can help plants to flower and produce fruit. Green light is not as effective for photosynthesis, but it can help to protect plants from damage. The amount of light that a plant receives is also important, and plants that receive too much or too little light can experience stunted growth or other problems. By understanding the role of light in plant growth, gardeners can create optimal conditions for their plants to thrive.

Here are some key takeaways from this article:

• Blue light is the most beneficial wavelength for photosynthesis.
• Red light can help plants to flower and produce fruit.
• Green light is not as effective for photosynthesis, but it can help to protect plants from damage.
• The amount of light that a plant receives is also important, and plants that receive too much or too little light can experience stunted growth or other problems.
• By understanding the role of light in plant growth, gardeners can create optimal conditions for their plants to thrive.

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Behind the scenes with light and color.

Introduction

Light and Spectrum is a common topic among all of the sciences. You will find a chapter devoted to it in Astronomy, Chemistry, Physics, and Biology. Therefore, enhancing your ability to teach this topic is going to benefit every member of the science department. The RSpec-Explorer empowers teachers to have their entire class to experience quantitative spectroscopy at the same time and in a meaningful way. Up until now, it was very difficult to manage to get more than one person to be sure they were seeing the same thing through a diffraction grating or a refraction table. But with the RSpec-Explorer you can easily point out features in a gas tube line spectrum, a sodium lamp, or anything you can think of. In this article, I provide 10 examples of experiments you can do on light and spectrum, all of which are made easier by using the RSpec-Explorer.

1. Experiments on Color One of the first experiments you should do is to demonstrate that white light is made of colors. The term "white" is often used by scientists to refer to a light source that emits or reflects all visible wavelengths (400-700nm). However, the human eye cannot distinguish this real white light from a light source that is made of only a few colors. For example, if you examine a cell phone flashlight feature through a diffraction grating (such as the one on the RSpec Explorer's camera) it will reveal that this apparently "white" light is actually missing some of the deep blues. Also, if you look at a "white" fluorescent lamp tube, it will reveal that it is made of several distinct colors but not a broad spectrum (like say for example a sunbeam, or a white incandescent lamp).

The white light of the iPhone flashlight turns out to be deficient in the light blues. Unlike the even spread of color that would come from sunlight.

If you have a color mixing device (three colored lamps would work, or three lamps with filters) you can demonstrate to yourself that "white" light can be created by mixing Red, Green, and Blue (RGB). This is how a cell phone screen makes white light, and a computer screen, and most projectors! There are many sources available for this experiment.

Magenta being faked by mixing red and blue. The spectrum on the right reveals the peaks of these two colors: 425 and 610nm.

A better trick is to mix just two colors and get a new color that will completely fool the eye. A major example is to mix red and green light and make "yellow." I put the quotes here again because it only appears yellow – there is nothing yellow about green and red light mixed, except that it can fool the eye by appearing to be yellow. Mixing red and blue light makes "magenta" light and mixing blue and green makes "cyan" (again the quotes describe the appearance not the reality of the light).

The advantage of analysis through a diffraction grating is that it can easily discern the two colors, which diffract differently. The spread or "dispersion" of the light is linearly-dependent on its wavelength (to a good approximation). That's how we can separate the light by its wavelength and reveal whether we are looking at a true color or only a synthesized one.

2. Ionized Gases Ionizing Gases to display their spectra is an important activity in most science classes. Of course, you want to point out that different gases have different spectra and these can be used for identification. Every noble gas was identified first based on its spectrum. (How else could you tell Neon from Argon, seeing as how they are both chemically inert?!!)

Gas tubes discharging: Hydrogen, Helium, Neon, Mercury.

The most important example is hydrogen, which is not a noble gas, but which has a readily recognizable spectrum. The Balmer Series (n=2) is the visible portion of the spectrum. It has a very obvious and bright cyan (486nm) colored line, a somewhat less bright red line (656nm), and a few violet lines (434nm, 410nm). Invisible is the Lyman (ultraviolet, n=1) and the Paschen (infrared, n=3) series. The hydrogen spectrum is important, not just because it is so familiar, but because it can be calculated easily (using the Rydberg formula below), and it was also the spectrum that was used by Niels Bohr when he applied quantum theory to explain atomic spectra for the first time.

The Balmer series for hydrogen contains the four visible lines of hydrogen's spectrum and all of these transitions involve the n=2 orbital (marked in yellow).

The four characteristic spectral lines in the Balmer series for Hydrogen.

Helium, on the other hand, is not as familiar but can be made so by learning to recognize it by its bright yellow (589nm) line. Also, the story that the helium absorption lines were first seen in a solar eclipse is a good history of science tidbit. That is how helium got its name, from the sun god – Helios. Also, helium looks yellow-pink when ionized, where hydrogen usually looks red-purple.

Recognize Helium based on its bright yellow discharge line and its pale yellow spectral tube.

Neon is amazing to look at even without a diffraction grating. Its pastel-electric red glow earned it its name as the "new" element for the electric age. The diffraction grating reveals that it is saturated with reds, yellows, and a few scattered greens.

In the plasma globe you can find ionized gases and with the RSpec-Explorer and (if you can line it up carefully) you can identify the gases inside (helium is the main one). It is also possible to burn salts and reveal the spectral lines. The most obvious salt is table salt, sodium chloride, which burns well in a paper clip loop held over a candle flame. Teachers often dissolve a lot of salt in a little water which can sometimes help (dissolved ions have more surface area/volume than crystals so they burn easier). The yellow sodium "doublet" (two very close wavelengths at once) easily identifies it. You can also recognize sodium in yellow streetlights at night. Other salts that emit good colors will contain copper, strontium, calcium, potassium, and iron. Which you can usually find in the chemistry storeroom. All of these are often used in fireworks (usually mixed with magnesium and gunpowder) and if you need help getting the fire hot enough, you should try dissolving them in methanol. Safety first! Be sure to have safe water on deck for emergencies and a fire extinguisher is a good idea, too.

A paper clip bent to include a small loop does a great job of carrying salt to the flame.

3. Investigate Different Light Bulbs These days people are very interested in how all the different types of light bulbs make light. Diffraction is the best way to identify how the light is made. If you look at an ordinary incandescent bulb you will see it has a broad spectrum with a lot of yellows and reds giving it a "warm" glow. On the other hand, fluorescence light bulbs contain mercury and will have several easily recognizable spectral lines that correspond to that element. Mercury is a good choice for fluorescence because the many energetic purples and UVs in the spectrum can give energy to fluorescent paints which reradiate that energy as visible light. If anyone doubts that there is mercury in our light sources, they should be easily convinced by this demonstration!

A mercury discharge tube demonstrates several violets and greens.

Compared to incandescent bulbs, fluorescent bulbs tend to make people look drained of color. This is because the high amount of blues and purples can cast an "unhealthy" purple glow on you. A 100W incandescent bulb nearly imitates the sun's spectrum. Which peaks in yellow-green, giving you that healthy glow.

A fluorescent light bulb shows many of the same spectral lines as mercury.

You can also investigate other light sources such as white diodes (which have a lot of purples because they fluoresce, too), yellow sodium parking lot lights, or even a plant light. Plant lights aim to provide the two spectral colors of photosynthesis – blue and red. Green plants reflect green light and thus they do not absorb it for making glucose. Red light also provides a signal to the plant to let it know that the day is long enough (i.e. spring or summer) to start investing itself in growth. (Some plants actually suppress their growth in summer to take advantage of a less competitive winter season.) Anyways, plant lights provide these non-green colors in high supply.

An incandescent bulb reveals its warm colors by peaking in the reds and yellows.

4. Analyze the Wavelengths of Lasers and Diodes Light Emitting Diodes are a ubiquitous source of light in our lives. In most cases, diodes will be sold to emit a specific wavelength of light but in actuality, there will be a spread of color about this "nominal" value. (Nominal is an engineering term meaning "named" or expected, as opposed to what actually results during the experiment.) For example, a "626nm" LED might emit 96% of its light between 610 and 632nm. This amount of spread can be measured by the RSpec-Explorer and it's interesting to compare this with laser light.

The orange diode demonstrates that its wavelength is quite spread out over the 30nm that surrounds its nominal value.

Lasers have "monochromatic" light. This means that it is very nearly only one specific wavelength. These wavelengths are usually listed on the laser itself. A good experiment would be to verify that the wavelength printed on the laser is actually the wavelength it emits.   Even diode lasers are usually quite monochromatic. "Lasing" requires the light to be nearly one wavelength – lasers are a good example of light standing waves.

A HeNe laser demonstrates both that it is monochromatic and that it contains neon by emitting the 626nm red that helium lacks.

When it comes to red lasers there are many different types. Helium-Neon lasers will have different wavelengths than red diode lasers. You can use the RSpec-Explorer to prove that it is actually neon that emits the red light in the helium-neon laser. This is a good demonstration of the power of spectral analysis to identify elements. If you have a bare helium-neon laser it can be particularly engaging in this activity.

A bare helium-neon laser glows yellow pink but emits a neon red beam.

5. Investigate Fluorescence Fluorescence is always an engaging activity.   Energetic light (such as UV or violet) lands on a substance that can absorb it and that energy is re-emitted as less energetic visible light. For example, a black (UV) light might shine on your socks (which have fluorescent detergent) in them and then white visible light will be emitted. Good candidates for investigation with the RSpec-Explorer include tonic water, highlighters, extra virgin olive oil, Willemite, and phosphorescent vinyl sheets. All of these will glow under UV or violet light (such as a violet laser or black light) but the olive oil works better with a green laser (the yellow olive oil absorbs violet light very quickly).

A violet laser energizes the quinine in tonic water.

Phosphorescence is a special type of fluorescence in which the emission of the light is suppressed for an extended period of time (the atomic transition is slower). In fluorescence, the emission of light is nearly instantaneous. In either case, the wavelength of the emitted light is always longer – less energetic. The words phosphorescence and fluorescence are only historical. Not all phosphorescent materials contain phosphates (though most do) and not all fluorescent materials contain fluorides (though many do, including toothpaste). Willemite, which is a fantastic glow rock, contains neither phosphorus nor fluorine.

A few fluorescent rocks with UV turned on. Willemite is in the middle.

6. Measure Temperature Using the Blackbody Curve Turn on your electric oven, toaster, or electric stove and it will first glow red-hot, then yellow-hot, and if we went further it would glow white-hot. This change in color with temperature was described mathematically by Lord Rayleigh, James Jeans, Wilhelm Wein, and finally Max Planck. The Rayleigh-Jeans Law described the long wavelengths and Wein's Law described the short wavelengths, but both "laws" failed outside of those conditions. Planck was the first to solve the emission problem for ends of the curve. Planck's function is also called the "blackbody" curve because even a black object will be seen to emit light in these proportions if it gets hot enough.

The Reference Library includes Planck Curves which can be used to fit to our spectrum.

We can use this curve to determine how hot our light bulbs are. The problem is that most of the light they emit is infrared which is generally not visible. If you are willing to accept that there is an enormous amount of invisible light, then you will be able to approximate the temperature of a glowing hot object by this method. You may be surprised to find out that even little circuit-lab style bulbs are actually heating up to about 4000K – but this is consistent with theory.

I am not saying that you can get a highly accurate measurement with the RSpec-Explorer camera, but you can approximate the temperature reading, and probably within 15% (be sure to turn the brightness down in the settings). It is impressive that lightbulbs get this hot to glow. It also helps us appreciate why they must be contained in bulbs – if they were exposed to the oxygen in the air at these temperatures they would immediately burn up and break the circuit.

It's fun to compare these light bulb filaments to the temperature of the sun which is a G2V star (there is a star reference collection in the References, too). The temperature of the sun can be determined from the black body curve as well. In fact, this is how we measure the temperature of the sun – at least on its surface!

Measuring temperature using the blackbody curve is a good way to get Modern Physics concepts into your classroom.

7. Diffraction Experiments In Astronomy and Physics, the idea of Diffraction is a commonly taught subject. Diffraction of light is one means by which we can separate it based on its wavelength. A diffraction grating is made when a laser cuts tiny grooves into the surface of a piece of plastic or glass. A good example of one is a CD. Some themes of diffraction are that the smaller the distance d between the grooves, the more dispersion, X, you will get. The light will spread apart further from its straight line path. Also, the longer the wavelength, λ, of the light the more easily you can disperse it. And of course, the more space it has to travel before it lands on a screen the more it will disperse. This length is usually called L (the distance to the screen or camera). All of these ideas come together in the diffraction formula:

X m = m λ L / d

where m is an integer, usually 1, that tells you the "order number." We need m because the pattern will repeat itself about twice as far out, and that is called the 2 nd order. Usually, the 2 nd order is much less bright than 1 st order diffraction. This formula is an approximation, assuming that the light is not being diffracted at large angles from the straight-ahead path, it works well for angles under 30 degrees (ie first order).

You'll have to measure both the dispersion X (left) and the distance to the camera L (right) if you wish to apply the diffraction formula. The wavelength λ is given in this case, which is unusually convenient. What is not given is th e groove spacing d.

A good lab would be to use this formula to try to measure the line spacing "d" for the diffraction grating of the RSpec-Explorer camera. The units should be in meters/groove or meters/line. Use meters as the unit for X, λ, and L.

8. Measure the Wavelength of Infrared The wavelength of Invisible Infrared Light can be measured with a diffraction grating and a digital camera (which can see the infrared light). But, the RSpec-Explorer makes this easier because it can tell you the wavelength based on the distance the light is diffracted on the video screen. A TV remote control can provide a source of near-infrared light (should be between 800 and 1000nm) but I have had more success with loose infrared diodes because I can crank up the voltage and get them to shine very bright. To ensure success, have a very dark room with the diode close to the camera. Also, when you rotate the camera you should be able to see the first order diffraction of the infrared light.

An infrared diode (bright circle) and its lens flare (dimmer circles) are plainly visible in this screen capture. Lens flares occur when bright lights are improperly focused by lenses.

To perform this experiment, get your diode showing up very bright, and line it up on the yellow calibration line. You will not be able to see the diffracted light because it will be diffracted so far that it will not appear on the screen. So instead we will have to recalibrate the camera to see further than the visible spectrum. First, line up a second light source with a familiar visible spectrum such as a Hydrogen gas tube or a white diode. Then, once you have it on the yellow line, rotate the camera to the right. This should cause the two light sources to be off-camera to the left but the color spectrum will remain. Based on your knowledge of that familiar spectrum you can recalibrate the camera. Go to Tools à Calibrate à Linear . Click on the first familiar pixel and enter its wavelength (in the case of hydrogen this would be the 486nm cyan line). Then click on the second pixel and set that to another wavelength (in the case of hydrogen this would be the 656nm red line). Now "apply" that calibration and close the window. Turn off your familiar light source and the infrared light should now be visible around 900nm. Be sure to move the yellow bars to sample it and explore its peak brightness. Like all diodes, infrared ones have a significant spread.

A screen capture taken after recalibrating the camera to explore the infrared. The hydrogen spectrum was used as a familiar reference. The next step would be to double check that the infrared diode was lined up with the hydrogen tube at the origin, and then turn off the hydrogen tube to reduce accidental light contamination.

9. Experiments that use the Intensity Feature   You probably have already noticed that brighter spectral lines show up as higher peaks on the y-axis. This is particularly obvious with the hydrogen spectrum's cyan line at 486nm which is much brighter than its red 656nm line. This intensity reading feature can be helpful in other experiments as well. To take advantage of this feature, be sure to turn off the "Auto-Scale Y-Axis" feature on the bottom right panel of the screen.

A good experiment to try out is to block a light source with two polarizing sheets. When the polarizers are rotated they block more of the incoming light. As the relative angle increases (to 90 degrees) the blocked light source dims to nearly zero transmittance. This reduction in brightness is supposedly dependent on the square of the cosine of the relative angle between the polarizers. This intensity function I (θ) = I max cos 2 (θ) is known as Malus' Law. It is helpful if the source of light is monochromatic.

Crossing Polarizers can reduce the Intensity of the light that comes through.

Another experiment that you can try (one that probably belongs in a Chemistry class) is that a higher concentration (molarity) of dye will block a proportionately larger amount of light. This is known as Beer's Law. It might be best to start with a clear water sample for calibration then slowly add dye. I have had a lot of success with Coca-Cola. Again, it is helpful if the source of light is monochromatic.

In this Beer's Law Experiment, the concentration of the solution is increased, causing the intensity of light to be decreased. Moussing over the central plateau makes an intensity measurement. It is important to set a constant scale for the y-axis. I have chosen not to fill the graph with color because the wavelength of light is not being measured, only brightness.

10. Astronomy Experiments The RSpec software that is employed with the Explorer camera was originally produced to serve astronomers. Thus, there are many vestigial traces of this in the reference libraries and in the training videos that accompany the device. It can be fun to take advantage of these features and see how far one can push the camera. You can view the solar spectrum by reflecting sunlight from along the length of a needle at the camera. Since all that is required is to view it is a bright source of light lined up along the yellow 0 nm line, it is quite possible to take advantage of this and observe the sun. Most visible in the spectrum will be the g2v black body curve and, if you zoom in, the Fraunhofer Absorption lines.

Here the reference library is used to investigate a g2v star. This is the same type of star as the sun. The next move would be to click Planck and check that 5700K is the right temperature for this curve.

Perhaps an easier demonstration is to view the clear, blue sky through a slit. This reveals that the blue sky is actually a mixture of all colors with more blue than any other color. The truth is that there is actually a little more violent than the camera can reveal but like the human eye the camera is less sensitive to violet than to blue. This "unsaturated blue" (meaning blue + white) is consistent with the Rayleigh Scattering Model for why the sky is blue.

If you own a telescope you may be able to analyze the spectrum of the stars with the RSpec-Explorer. Because of the sensitivity limitations of the camera, it is not possible to observe stars without a telescope. But, a telescope can help a lot. Be sure to know which star you are looking at (I recommend Sirius, Betelgeuse, and Vega), then look up what type of star they are (a1v, m2i, a0v respectively).

Conclusion Experiments on light can be very engaging, but they can also be very confusing. It is important that we take steps to ensure that our students are able to view what they are supposed to be seeing, and recognizing what is being pointed out. The RSpec-Explorer projected overhead for your students' benefit is probably the best way to in engaging your students in spectroscopy (especially if used in conjunction with hand-held spectrum analyzing devices). I have found that students are very interested in cameras and how they can see things that our eyes cannot. If building a community of learners in your science classroom is your goal then you should add this device to your collection of lab equipment.

Old-fashioned – but not obsolete – spectrum analyzing equipment.

James Lincoln Tarbut V' Torah High School Irvine, CA, USA

James Lincoln teaches Physics in Southern California and has won several science video contests and worked on various projects in the past few years. James has consulted on TV's "The Big Bang Theory" and WebTV's "This vs. That" and the UCLA Physics Video Project.

Contact: [email protected]

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Home > EVENTS > SCJAS > 2017 > ALL > 16

The Effect of Different Color Light affect The Growth of Plants.

Wenlan He , Heathwood Hall

School Name

Heathwood Hall

Grade Level

Presentation topic, presentation type.

Non-Mentored

The purpose of this experiment was to find out how different color of lights affect the growth of plants. Six of different colors lights were set for the plants, and therefore the results would shows which light would produce the highest plants, which means let the plants absorbs the most lightning energy. The subjects used in this experiment were under the color gel, and let the subjects grew for a month, and compare the data on different height of the plants. The hypothesis of this experiment was, the plants under purple light would have the highest length in. The results of this experiment didn’t support the hypothesis. In conclusion, this experiment will help the farmers, by using which light would make plants grew well.

Recommended Citation

He, Wenlan, "The Effect of Different Color Light affect The Growth of Plants." (2017). South Carolina Junior Academy of Science . 16. https://scholarexchange.furman.edu/scjas/2017/all/16

3-25-2017 11:45 AM

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Oral and Written

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The Biology Corner

Biology Teaching Resources

Observe Photosynthesis with this Easy Experiment

Photosynthesis is a complicated topic that requires students to develop mental models of the phenomenon. Teachers may struggle to find hands-on activities that can be completed in a short class period.

There are several ways this can be accomplished. Students can observe the products created by photosynthesis, oxygen. In this lab, students cut small disks from spinach leaves and record the time it takes to float.

You can also indirectly measure photosynthesis by the amount of carbon dioxide absorbed during the process. I have another lab that can be a demonstration for the whole class where students can see the effects of photosynthesis. In this demonstration, an indicator ( phenol red) is used to measure the amount of carbon taken up during the process.

Class Demonstration

The demonstration is simple. You take leaves from a plant and place it in the indicator solution. The plants exposed to light will consume the carbon dioxide which decreases the acidity of the solution. The yellow solution will turn red!

I have used elodea leaves in the past, but find that these specimens have become hard to acquire. Many states consider this water weed an invasive species and limit shipping. Luckily, leaves from kale will also work. Kale is a fairly inexpensive vegetable you can get at the supermarket.

The demonstration is simple. Phenol red starts out as a red color but will change to yellow if you blow into it with a straw. The carbon dioxide in your breath will change the solution to a yellow color.

Next, place leaves from kale into test tubes with the yellow solution. Place one tube in the light and another in the dark (using aluminum foil).

A full spectrum grow light will have the best results. Leave one test tube empty as a control. In about 20-30 minutes, the test tube in the light will change to red, indicating that the carbon dioxide has been consumed.

You can use this demonstration as an introduction to photosynthesis, or a plant unit. Follow up with a discussion that asks students the following questions:

• Why does phenol red change color when I add carbon dioxide?
• Why does it turn back to red in the tube with a plant exposed to light?
• Why did the plant in the dark not change color?

If you want a more student-directed activity, students can do the lab for themselves. This handout outlines the procedure and includes discussion questions for students to answer in groups.

As an extension activity, ask students what will happen to the tubes if left to sit overnight. Generally, the color will change to yellow as plants respire and release carbon dioxide. (Note: I have had mixed results with this, but it’s a good way to prompt discussion about the relationship between respiration and photosynthesis.)

Shannan Muskopf

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• Why We’re Unique

Plants in different environments (light intensity, color)

Plants in different environments, (light intensity, color), introduction: (initial observation).

So here is the problem with which you are faced.

You have someone who appears to have found that plants don’t grow as well (or die) under some types of light and he wants to know why, so he asks you and wants you to do a research and come up with information that he can use to prevent such problems in future. So first you have to decide what parameters can you truly manipulate or measure. What do we mean by “different types of light”? Well incandescent and fluorescent lights are different, but how? They are different in heat output, colors of light and light intensity.

Because of the distance between the light source and the plant, heat can not be a very influential factor in this case. However the light color and the light intensity could be affecting the the plant growth.

In this project you will perform experiments to determine the effect of light intensity and light color on plant growth.

This project guide contains information that you need in order to start your project. If you have any questions or need more support about this project, click on the “ Ask Question ” button on the top of this page to send me a message.

If you are new in doing science project, click on “ How to Start ” in the main page. There you will find helpful links that describe different types of science projects, scientific method, variables, hypothesis, graph, abstract and all other general basics that you need to know.  

Project advisor

Information Gathering:

Find out about what you want to investigate. Read books, magazines or ask professionals who might know in order to learn about the effect or area of study. Keep track of where you got your information from

Image in the right shows a plant cell.

Vacuole is a single membrane, containing water, food, or metabolic waste.

Chloroplasts contain chlorophyll that is needed for photosynthesis.

General Thoughts

OK, so let’s say you think that infrared light is something to test (Why?). Do you shine it on the plant and measure its growth? Would you really see a measurable difference in plant growth in 2 hours? (Hint – No!). Would this experiment answer your question? You already has evidence that the plants don’t grow as well in a certain light condition, you wants to know WHY! Showing that plants grow better under different colors of light will not answer the questions anyway.

Is there a parameter that is correlated with growth that you could measure? Growth requires energy. So this should make you think about metabolic rate and cellular respiration. What process that is dependent on light and that only plants (and algae and cyanobacteria) do provides “food” and energy?

You have to come up with a hypothesis in the truest sense. What do we mean by that? Hypotheses are explanations for phenomena – What is the mechanism or cause for what is observed. Look at the concept map below. It shows a variety of relationships and posses questions about the process you should be investigating.

You should be testing some idea of why the plants do not grow well under different color lights not whether they grow better under different color light and you can’t test growth but must measure something that contributes to growth.

You now know that light is required for the process of plant growth, and that the light interacts with the chlorophyll (the green pigment inside chloroplasts). But which colors of light are most important? Will a green plant grow in just any light? If a pigment is blue in color, what does that tell you about the colors of light that must be absorbed by the pigment? An artist could tell you the answer in a flash. But let’s try to find out through an experiment.

Something to do …

What colors are absorbed most by chlorophyll?

To answer this question, you must first find some way to shine various colors of light onto a green plant and observe how the process of plant growth is affected. First think about the process itself. You would expect to have oxygen produced, and the more the process is going on, the more oxygen is produced. Similarly, glucose is made and usually stored as starch. Also, carbon dioxide and water are consumed. Now, what is easiest to detect? You have already observed bubbles of oxygen. Perhaps you can do the experiment with an aquatic plant and just count the bubbles.

But how will you get colors of light? You may remember that Isaac Newton used a triangular prism to break light into its colors. You could use a prism to break light into its colors and shine that light onto an aquatic plant just below the surface of water. Where you see bubbles, you can infer that oxygen is produced.

Try to design and carry out such an experiment. What kinds of problems did you encounter? What colors of light were absorbed the most? Which ones the least?

In 1833 the German botanist Theodore Engelmann did this experiment, but in a somewhat different way. Engelmann used an alga, Spirogyra, that has long spiral chloroplasts. He placed the alga on a microscope slide with aerophilic (“air-loving”) bacteria, which move toward regions of greatest concentration of oxygen. Using a prism to disperse the light, Engelmann illuminated different parts of the alga with different colors. He thought that the plant would produce the most oxygen where light of a given color was absorbed the most. He would therefore see the most bacteria in that region.

Engelmann observed that the bacteria did indeed concentrate in the region where red light fell, and also in the region where blue light fell. If you remove red and blue light from white light (that is, if those colors get absorbed), what color is left? Mainly green! And that’s the color that gets reflected to our eyes from the leaves of living plants.

Some keywords:

Absorbance: The ability to take up electromagnetic radiation by objects; different wavelengths of the visible light spectrum have different absorbances and appear as different colors.

Absorption Spectrum: The particular wavelengths of light that are absorbed by objects, e.g. pigment molecules, measured by a spectrophotometer.

Action Spectrum: Rate of activity in relation to wavelength of light, e.g. photosynthesis most active in blue and red parts of the visible spectrum

Chlorophyll a: Primary photosynthetic pigment in all organisms except bacteria; absorbs red and orange (600-700 nm) and blue and violet (400-500 nm).

Phycobilin: Water-soluble photosynthetic pigment

Solvent/Solute: A chemical in which others dissolve, forming a solution

Transmittance: The fraction of radiant energy that passes through a substance [syn: transmission]

Visible Light Spectrum: The small range of the electromagnetic spectrum that human eyes perceive as light. Ranges from about 400 to 700 nm, corresponding to blue through red light

Wavelength: The distance moved by a photon during a complete vibration; dependent on the energy of the photon; higher energy photons have shorter wavelengths.

Question/ Purpose:

What do you want to find out? Write a statement that describes what you want to do. Use your observations and questions to write the statement.

The purpose of this investigation is to find out how different color lights affect the plant growth.

Identify Variables:

When you think you know what variables may be involved, think about ways to change one at a time. If you change more than one at a time, you will not know what variable is causing your observation. Sometimes variables are linked and work together to cause something. At first, try to choose variables that you think act independently of each other.

Controlled variables are:

• Light intensity
• amount and type of water and nutrients
• temperature
• rate of CO2 in the test environment

Independent variable also known as manipulated variable is the color of the light.

Dependent variable is the plant growth (height, dry weight, size or number of leaves.)

Since the amount of consumed CO2 and produced oxygen are correlated with the plant growth, you may also choose one of those as dependent variable.

Hypothesis:

Based on your gathered information, make an educated guess about what types of things affect the system you are working with. Identifying variables is necessary before you can make a hypothesis.

Some Bad Hypotheses

• Light makes plants grow.

Yes… but How? Why?

• Different colored lights make plants grow differently.

Too general. Which color(s) of lights? What is “different” growth?

• Red light affects photosynthesis.

Again, too general. How does red light affect photosynthesis? Why?

• Plants grow best in bright light.

How do you define bright light? How do you define the “best” growth?

• Plants grow good in green and blue light.

How will you test “good” growth?

• Plants on an average will grow an extra 2 inches in blue light than red light.

How will you test this?

Some Good Hypothesis

• Blue and black color lights that have lower wave lengths can accelerate the photochemical reactions of the plant (or photosynthesis) resulting the absorption of more CO2 from the environment and production of more oxygen and glucose that is ultimately converted to starch and cellulose.
• White color that is closer to natural light and contains many different wave lengths can provide more light energy to the plant resulting a higher rate of photosynthesis and plant growth.

Experiment Design:

Design an experiment to test each hypothesis. Make a step-by-step list of what you will do to answer each question. This list is called an experimental procedure. For an experiment to give answers you can trust, it must have a “control.” A control is an additional experimental trial or run. It is a separate experiment, done exactly like the others. The only difference is that no experimental variables are changed. A control is a neutral “reference point” for comparison that allows you to see what changing a variable does by comparing it to not changing anything. Dependable controls are sometimes very hard to develop. They can be the hardest part of a project. Without a control you cannot be sure that changing the variable causes your observations. A series of experiments that includes a control is called a “controlled experiment.”

Experiment 1:

Light is one of the most important environmental factors affecting plant growth. Light quality is a limiting factor in the growth of the plant. Chemical reactions and physiological reactions are controlled by the color of light.

Introduction:

You would select plants of the same species and alter the light color for those plants. Any potted plant would be acceptable for conducting this experiment.

Visible light consists of different colors having wavelengths of different ranges. Each wavelength of light causes chemical and thermal responses in plants that influence various phases of growth.

Plants should be exposed to a diversity of light colors. You may use color light bulbs as your light source. You may also use natural light and use color films or color glass or color plastic to filter the light so only one color will pass through.

To determine affects of the light on growth factors several observations should be made; length of internodes, leaf width and length, quantity and quality of flower production and quantity of leaves should be considered. Plant quality should also be a consideration. This would include strength of stems, color of the leaves and flowers, tissue damage and plant survival.

• 24 Tomato Plants
• White, Blue, Green, red and Black Light Bulbs ( Black light is near UV or Ultra Violet )
• Water and Watering Apparatus
• 5 fish tanks or boxes
• 5 lamps ( desk lamps or any similar light fixture )
• Electrical Plug and Electrical Resource
• Black Construction Paper
• 15 Small flower pots
• 5 Timer For Lights ( You may be able to use one timer for 5 lights. For more details read the packaging or ask the seller )
• About 25 Cups of soil

You may change the material and procedures as you need. For example you may decide to experiment with a different light source or different plant.

• Cover each fish tank completely, using the black construction paper and tape, so no other light can come inside.
• Label each fish tank a different light color: black blue green, red or white.
• Put 1.5 cups of soil in each of the 15flowerpots.
• Label each flowerpot a different light color: black blue green, red or white.
• For every color label each flowerpot a different letter: a b c. For example, Black A, Black B and Black C.
• Plant two tomato plants into each labeled flowerpot.
• Measure each tomato plant. If you are planting seeds, you need to wait a few days before starting the light experiment and doing your first measurement.
• Place three flowerpots in each fish tank, according to their labels. Ex. Black A, Black B, and Black C are grouped together in the same fish tank.
• Cut out a circle of the construction paper on the top of the fish tank big enough for the lamp to fit, so that the light can shine threw the fish tank and only the fish tank. There should be at least 2 feet distance from the lamp to the plant.
• Place each lamp with the colored light according to the labeled plants. Ex. Black light would go on top of the fish tank with the Black A, Black B, and Black C flowerpots.
• Set lamp timer to turn on light for 12 hours and off for 12 hours each day.
• Water each plant with 20 ml of water when all of the plants are dry to the touch. Remember to water all the plants on the same day and at the same time.
• Measure each plant to the end of its stem every three days for six weeks.
• At the end of the six week period take the measuring results and put them into a chart.
• Which ever plant, out of the plants placed under the blue, black, green or white lights, has the highest growth percentage shows which color of light offers a better growing capability for tomato plants.

A Different Method and a totally different experiment

The main challenge in this project is to decide how are we going to test the rate of photosynthesis? In previous experiment we let the plant grow for a few weeks and then measured the height of plants. Height represents plant growth but is not enough in many cases. Maybe in addition to height we could also count the number of leaves or measure the area of the leaves. We can also dry the plants and weight them to measure the dry weight as an indication of plant growth. Some of the other methods that we can think of are:

• Photosynthesis absorbs carbon dioxide. If we perform our tests in a closed container, we can measure and use the rate of carbon dioxide reduction as the rate of photosynthesis. But a carbon dioxide monitoring tool is about $500 that seems too expensive for a science project test.
• Photosynthesis produces oxygen. If we perform our tests in a closed container, we can measure and use the rate of oxygen production as the rate of photosynthesis. However, there is no tool that easily monitors and shows the rate of oxygen in the air. We could possibly try to burn a candle inside the container and estimate the oxygen amount based on the burning time of candle, but this does not produce a reliable result.
• Photosynthesis produces organic material that form the body of the plant. In other words growth of the plant is the direct result of photosynthesis. So we can measure the weight of dry plant and use it as a product of photosynthesis. This requires a longer period of experiments. In order to produce enough organic material (plant body) and weight it, you need to continue each experiment at least 30 days. Otherwise the amount of weight increase will not be enough to provide you with reliable results.
• Final way that is a quick and inexpensive method is using a water plant. Oxygen produced by a water plant can be gathered under a glass tube such as a test tube and can simply be measured. Following is the detail:

Experiment 2:

In this experiment we will observe evidence of photosynthesis in a water plant. We will assemble the equipment needed to measure the rate of photosynthesis in elodea (or any other water plant). We count or collect bubbles of oxygen gas given off by elodea to determine the rate of photosynthesis. We will then change the conditions of photosynthesis by altering light intensity, and determine the effects on the photosynthesis rate. Finally we prepare a graph of the collected data and analyze it.

Materials Needed:

• Pond weed like Elodea or Lagarosiphonelodea (water plant)
• Lamp (40 watt)
• Test tube or measuring cylinder
• Razor blade (single-edge)
• Dechlorinated water (room temperature)
• Sodium bicarbonate powder (baking soda)
• Clock or timer
• Metal stand with rod or test tube rack
• Metric ruler

PART A. Setting Up the Experiment 1. Obtain a sprig of Elodea. Remove several leaves from around the cut end of the stem. Slice off a portion of the stem at an angle and lightly crush the cut end of the stem. 2. Place the plant into the test tube, stem end up, filled with water. 3. Secure the test tube to a metal stand with tape or place the test tube in a test tube rack. PART B. Running the Experiment 1. Place a 40 watt lamp 5 cm from the plant. After one minute, count and record the number of oxygen bubbles rising from the cut end of the stem. Count bubbles for five minutes. If bubbles fail to appear, cut off more of the stem and recrush. 2. Run a second five-minute trial. Record and average your results. 3. Move the lamp so it is 20 cm from the plant. After one minute count and record bubbles for two five-minutes trials. Again, average and record your results. 4. Add a pinch of sodium bicarbonate powder to the test tube. Place the lamp 5 cm from the test tube. After one minute, record bubbles for two five- minute trials. Average and record your results. 5. Prepare a graph of your results. Use the average number of bubbles for the vertical axis. Use the type of environmental condition for the horizontal axis.

Instead of counting bubbles we can collect bubbles under a test tube or measuring cylinder, so we can measure the volume of oxygen. You just need to place the plant in a larger clear container and use a funnel to direct the oxygen into the test tube. (Note that you need to fill up the test tube with water, use your thumb to close the mouth of the test tube and turn it over into water. No bubbles must be in the tube at the start of your experiment.

Use the result of your experiments to answer these questions:

1. How does this investigation demonstrate that plants give off oxygen during photosynthesis? Explain your answer based on your observations. 2. How does the rate of photosynthesis change when the light source is moved from a distance of 5 cm to 20 cm? 3. How does the rate of photosynthesis change when sodium bicarbonate is added to the water?

Conclusions:

Plants use green pigments called chlorophylls to trap light energy. The

chlorophylls give a plant its green color. Inside the cells that have

chloroplasts, the light energy is used to make a simple sugar called glucose.

The process by which plants use light energy to make glucose is called

photosynthesis.

During this process of sugar production, carbon dioxide combines with water to

form glucose and oxygen is released. Oxygen that is produced in photosynthesis

is given off as a gas. If a lot of oxygen is being given off, photosynthesis is

occurring rapidly. If little oxygen is being given off, photosynthesis is

occurring slowly. The amount of trapped light energy and the amount of carbon

dioxide available affects the rate of photosynthesis.

The purpose of adding sodium bicarbonate powder to the water increases the

amount of carbon dioxide in the water.

This investigation can be performed with water plants grown in many parts of

the world, except regions that have permanent ice.

You can use the same procedures with different color lights to see how different color lights may affect the release of oxygen produced by photosynthesis action.

Materials and Equipment:

Materials for tomato plant growth under different color lights

• White, Blue, Green, and Black Light Bulbs
• 4 fish tanks
• 12 Small flower pots
• Timer For Lights
• About 18 Cups of soil

Results of Experiment (Observation):

Experiments are often done in series. A series of experiments can be done by changing one variable a different amount each time. A series of experiments is made up of separate experimental “runs.” During each run you make a measurement of how much the variable affected the system under study. For each run, a different amount of change in the variable is used. This produces a different amount of response in the system. You measure this response, or record data, in a table for this purpose. This is considered “raw data” since it has not been processed or interpreted yet. When raw data gets processed mathematically, for example, it becomes results.

Make daily observations and water the plants as needed. Measure the plant height every 3 to 5 days and record the results in a table like this.

By taking average plant height for each color light you can simplify the above results table to a new table like this:

* When taking average, you may choose to take the average of all daily observations or just the last day for the 3 test samples exposed to each color light.

Make a graph:

Use the above results table and make a bar graph to visually present your final results. Your bar graph may have one vertical bar for each color light you test. The height of each bar will represent the plant height or plant growth under one specific color.

Calculations:

You will need to calculate the average height of plants in each group.

Summary of Results:

Summarize what happened. This can be in the form of a table of processed numerical data, or graphs. It could also be a written statement of what occurred during experiments.

It is from calculations using recorded data that tables and graphs are made. Studying tables and graphs, we can see trends that tell us how different variables cause our observations. Based on these trends, we can draw conclusions about the system under study. These conclusions help us confirm or deny our original hypothesis. Often, mathematical equations can be made from graphs. These equations allow us to predict how a change will affect the system without the need to do additional experiments. Advanced levels of experimental science rely heavily on graphical and mathematical analysis of data. At this level, science becomes even more interesting and powerful.

Conclusion:

Using the trends in your experimental data and your experimental observations, try to answer your original questions. Is your hypothesis correct? Now is the time to pull together what happened, and assess the experiments you did.

Related Questions & Answers:

What you have learned may allow you to answer other questions. Many questions are related. Several new questions may have occurred to you while doing experiments. You may now be able to understand or verify things that you discovered when gathering information for the project. Questions lead to more questions, which lead to additional hypothesis that need to be tested.

Possible Errors:

If you did not observe anything different than what happened with your control, the variable you changed may not affect the system you are investigating. If you did not observe a consistent, reproducible trend in your series of experimental runs there may be experimental errors affecting your results. The first thing to check is how you are making your measurements. Is the measurement method questionable or unreliable? Maybe you are reading a scale incorrectly, or maybe the measuring instrument is working erratically.

If you determine that experimental errors are influencing your results, carefully rethink the design of your experiments. Review each step of the procedure to find sources of potential errors. If possible, have a scientist review the procedure with you. Sometimes the designer of an experiment can miss the obvious.

References:

List of References

See a sample project

Following images shows the experiment of testing the effects of different color lights on the growth of radish seedlings. Experiment is performed in Petri-dishes. Colored cellophane is used as a light filter. Filter paper is used to distribute moisture.

The Petri Dish Method for Germinating and Growing Fast Plant Seeds Under Experimental Conditions

The seeds easily adhere to the wet filter paper that is placed in the top of the petri dish. The covered petri dish is then placed, almost vertical, in the bottom of a 2 liter soda bottle, which is filled with water or an experimental solution like 0.1% gibberellin.

It is always important for students, parents and teachers to know a good source for science related equipment and supplies they need for their science activities. Please note that many online stores for science supplies are managed by MiniScience.

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How light affects plant growth – what you need to know.

Light is something we all take for granted unless you live in the arctic circle or something! But if you get into gardening, or more specifically, indoor hydroponics, you start to appreciate how valuable sunlight truly is.

You cannot grow anything in the darkness. Mushrooms and fungi are an exception of course, but for any plants with green chlorophyll coursing through their leaves, light is mandatory.

Understanding light requirements are important for your plants as well as for your pocket/bank balance! Electricity does not come cheap, and your energy bills will shoot up if you don’t plan your hydroponics system properly.

So if you want to be a successful farmer, you need to know your photosynthesis and plant light requirements basics. Let’s get started then.

• Why Plants Need Light – An ELI5 Explanation

Photosynthesis is a topic that is done to death in our science classrooms. But unless you are a keen botany enthusiast or someone who pursued higher studies in the field, you probably don’t remember a whole lot about the process.

Let’s refresh that memory with a few basic concepts. Asking why plants need light is like asking why we need fire or heat to cook our food.

Plants are autotrophs, which mean that they are capable of creating nutrition (read carbs, proteins, and fats) in their bodies. To create these foods they absorb the following ingredients from the environment:

• Nutrients and Minerals from the soil via routes
• Water, again through the roots
• Carbon Dioxide, through the pores in the leaf.

To combine these ingredients and cook up some food, plants need energy. This they derive from the sunlight, using the green chemical called chlorophyll in their leaves .

The recipe reads something like this:

6CO2 + 6H2O — Chlorophyll & Sunlight —> C6H12O6 + 6O2

Carbon Dioxide and water, in the presence of Chlorophyll & Sunlight, combine to produce Glucose and Oxygen molecules. The glucose is used by the plants for growth and bearing fruit, while the oxygen is released into the atmosphere as a by-product.

This is a simple definition of the process of photosynthesis that happens in a plant leaf in the presence of chlorophyll and sunlight. You may have noted the absence of any minerals in the equation.

But minerals like magnesium and phosphorus are essential for photosynthesis. Without magnesium, plants cannot create chlorophyll in the leaves. And phosphorus is essential for creating proteins.

How Does Light Affect Plant Growth?

• Direction of Growth

The survival of a plant is entirely dependant on the source of light. In the case of all outdoor plants, the sun is the only source of light.

When the first leaves appear on the plant, it will try to grow towards the light source, to ensure that maximum light is received by the leaves for photosynthesis.

Some plants take this to its extreme and follow the sun as it traverses the sky in the day. The sunflower is the most famous example of these plants, called heliotropic by botanists.

The rest of the plants are called phototropic, which means that they respond to light. The stems of these plants try to grow towards the direction of the source of the light.

Consider a garden plant which is partially in the shade. When light shines on a part, it stimulates the secretion of growth hormones called auxins in that area of the stem.

These auxins cause that part of the stem cells to elongate, forcing the stem to grow towards the sunlight. These are changes that occur continuously through the life cycle of a plant.

• Seasonal Effects

If there is one disadvantage to sunlight, it is the fact that it is not constant all through the year. The duration and intensity of sunlight received fluctuate with the changing seasons.

So plants have adapted to these changing seasons as well. In the summer and spring, with light being plentiful, most plants focus on growth, blooming of flowers, and bearing of fruit.

When the light intensity and duration reduces as winters approach, the plants put more emphasis on conserving energy and reducing growth.

Photosynthesis is reduced in the fall, and leaves start losing chlorophyll. This is why leaves tend to turn brown, yellow, or red in autumn.

• The Importance Of Light Spectrum

Light is a form of energy that moves as an electromagnetic wave. What we see as visible light is made up of electromagnetic radiation in a specific range of wavelengths.

Visible light falls between the wavelengths of 390-700 nanometers. Light in different wavelengths appears as a particular color to the human eye.

When you use a prism to scatter the light, you can see these individual colors, as VIBGYOR or ROYGBIV.

Red light has the longest wavelength and the lowest energy, while blue and violet lights at the other end have short wavelengths and more energy. (This is one reason why energy-rich UV light is considered dangerous)

Like the cells in the human eye, the leaves in a plant also respond to the light energy falling on it within these 390-700nm wavelengths. To be more precise, the chlorophyll in the leaves absorb most of this light to create food.

We said “most of the light,” not all of it. Ever wonder why plants appear green? It is because chlorophyll reflects the green part of the spectrum (495-570nm).

Further reading:  –  Introduction – What is light? – Indoor Grow Lights

Out of the remaining wavelengths, red and blue color light seems to have the most impact on the health of a plant. These wavelengths have different impacts:

With a wavelength between 400-500nm, this light has high energy and affects the leaf growth (also called vegetative or “veg” growth) of plants. Blue light has an impact on chlorophyll production, but you only need it very small quantities when compared to red light.

If a plant does not get enough blue light, it will start getting weaker, with yellow streaks in the leaves instead of green.

This low-energy light has a wavelength of 600-700nm. It is essential for flowering and blooming of the plants.

Deficiency in this light wavelength will invariably result in delayed flowering or very weak blooming stage in plants.

Understanding the spectrum is vital for hydroponics. Out in the sun, plants get all the light energy they need in all the important wavelengths.

But as we will see in the next section, replicating the effect of sunlight using grow lights is not a very simple task.

• How Can Grow Lights Replace Sunlight

From what we have gathered so far, three major factors regarding light can affect the growth and development of a plant. These are:

Intensity:  How bright the light is, or how much energy in the form of photons is falling on the leaf. This determines the rate of photosynthesis. The higher the intensity, more photosynthesis occurs in the plant.

Duration:  How long the plant receives the light. Outdoors, this is regulated by the seasons, and plants have evolved their life stages around it. Arbitrary changes in light duration will affect the growth of the plant.

Spectrum:  Plants need both red and blue spectrum light to flourish at different stages of growth and to bloom.

In an indoor grow system, you will have to pick artificial grow lights capable of fulfilling all three factors. Of these, the duration is the easiest to replicate, as you just have kept the lights on for a set period.

Intensity can be a challenge with some grow lights. Growers change light intensity by changing the distance between the plant and the light bulb. The closer the light source, the more intense the light.

The problem here is that many grow lights also emit a lot of heat. So if you place the blubs too close to the plants, they may wilt or die. So a careful balance has to be maintained.

Wavelength is another challenging aspect. The sun is a perfect single source that radiates enough energy for the plants in all the wavelengths, blue and red.

We do not yet have a single light source capable of emitting both red and blue spectrum light in adequate quantities. Indoor growers get around this limitation by using a mix of warmer and colder lights.

Perfectly replicating sunlight indoors is not easy. But by using multiple light sources and constant tinkering, you can achieve phenomenal results with indoor grow lights.

Now to complete this article, we will take a quick look at some of the popular grow light options for indoor hydroponics.

Some Common Grow Light Options

• High-Intensity Discharge (HID) Lights:

These are special incandescent lights used widely in indoor horticulture. They are power hungry and emit a lot of heat. So you have to be careful when placing them close to the plants.

HID lights include High-Pressure Sodium (more red light) & Metal Halide (more blue light) options. Large-scale growing operations use these lights more than small-time hobbyists.

• Fluorescent Lights

These are less energy intensive and do not emit a lot of heat. They are long-lasting and easier to manage than HID lights as well.

But Fluorescent lights are known to emit cooler light at the blue end of the spectrum. So they may not be able to provide complete light that your plants need. If you are growing herbs, these are quite effective.

You will find fluorescent lights more often in small home-based grow systems. Many growers tend to mix them with other red-spectrum lights when growing fruit or flowering plants. The most common Fluorescent Lights used for growing are CFL grow lights and T5 grow lights.

These are gaining popularity these days, especially among hobbyists. Small, compact, and very energy efficient, they can be set up very close to the plants.

But they may not be suitable for large-scale grow operations, as they cannot spread intense light across large areas.

But LEDs can be designed to emit either red or blue spectrum wavelengths. And you can put a lot of these small LEDs in a light panel. So you don’t need to mix and match different types of lights when using LEDs. LED grow lights tend to be the most effective when it comes to growing indoors.

Light (and its energy implications) is one of the main limiting factors in hydroponics. The sun is a near limitless source of energy. Replicating it indoors is not easy. But the technology is evolving at a fast pace. We have grow lights that are more energy efficient than ever before. There is no reason not to expect a brighter future for indoor hydroponics. Hope you were “enlightened” by the contents of this post!

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Plant Growth Under Different Colors Of Light

Table of Contents

The effect of plant growth under different colors of the light spectrum plays a key role in how they flourish. As a grower, it is normal for you to want your plant to thrive beautifully, and supplying them with the appropriate colors of light is the way to go.

This is why you need to know the impact different colors of light have on the growth of your plant. In this article, we will enlighten you on how the various colors of light affect the growth of plants. So, read on to find out.

The varying colors of light have a tangible implication on how rapidly or slow your plants will develop. All green plants require either natural sunlight or artificial light that will switch on the chlorophyll that prompts nutrient production. This is done through the process of photosynthesis.

Light also plays a crucial part in the different growth stages of your plant’s life cycle. The energy from light is captured by the green pigment chlorophyll and this light is used to manufacture food for the use of plants.

Effect Of Plant Growth Under Different Colors Of Light

The color of light has a different spectrum and plants will assimilate each color but in different amounts. The absorption rate will determine how plants will flourish under each color.

Different colors of light come in different wavelengths and it is this wavelength that will determine how plants will take in colors of light . But have in mind that the more plants absorb light the more it boosts plants’ growth.

Blue light has a short wavelength and its energy potential is great. This light is known to enhance the growth of plants and it makes plants attain maturity more rapidly. It is particularly required during the early stage of the plant.

How Does Red Light Affect Plant Growth?

Red light has the longest wavelength when it comes to the color spectrum. It is great for plants’ growth but they are not so effective on their own.

Far-Red Light

We also have far-red light and it has a very low wavelength which is closer to the infrared wavelength. If you want abundant yield, far-red should be used. Far-red will help accelerate the growth process of the plant every time they go into the nighttime state.

Roleadro Grow Light for Indoor Plants, T5 LED Grow Lights 3500K & Red Blue Full Spectrum

Violet Or Purple Light

How does yellow light affect plant growth.

Yellow light does not have much effect on plant growth and no significant plant benefits have been seen with yellow light.

Ultraviolet Light

What hormone causes plants to grow towards light.

The hormone that ensures plant cells elongate and grows toward the sun is auxin. When light conditions are normal, auxins spread throughout the plant. When there’s more shade, auxins break down and move to the sunnier side.

Which Plants Can Grow in Artificial Light?

Which color of light bulb would be least useful for growing plants indoors.

You should use violet-blue grow lights for the best results. This color encourages chlorophyll absorption, helping plants photosynthesis and grow. Flowers are more likely to bud and bloom if you use red light.

How Do You Grow Plants With UV Light?

Growing plants with UV lights can be beneficial. UV lights can speed up germination and strengthen plants. You can use UV lights by hanging them over your plants and placing them at the sides of your grow room or tent.

How Long Should I Leave My Plants Under Grow Lights?

How far should led grow light be from plants.

How far a LED grow light should be from a plant depends on its wattage. It’s best to keep 200-watt lights at least 12 inches from the top of your plants. Lights with an even higher wattage should be a minimum of 35 inches from the top of your plants.

How Much Are Grow Lights for Plants?

You should use at least 20 watts of grow lights per square foot of plants. To determine how much you need, divide your bulb wattage between 20. How much this amount of light will cost you depends on several factors. The brand, size, and type of light are a few.

Conclusion On Does The Color Of Light Affect Plants Growth

We can now conclude that red and blue light has the most significant effect on plant growth.

How does different colored light affect plant growth?

The lights may be used to control the growth of plants indoors or outdoors. A white light is used to stimulate growth. The light stimulates photosynthesis. A white light is also used for colorizing the plants. Red light stimulates growth and promotes root development. It also improves the production of chlorophyll. It also reduces the growth of harmful bacteria. Blue light is used to promote flowering. It also helps to regulate circadian rhythms. Yellow light increases the production of sugar in the plants. It also improves the production of chlorophyll. It also stimulates the growth of root hairs. Green light is used to promote plant growth. It also controls the growth of weeds and pests. It also stimulates the formation of chlorophyll. Green light is used to control the growth of weeds and pests. Orange light is used to promote root growth. Orange light is also used to stimulate the production of chlorophyll.

What color light produces the most flowers?

What should i consider when choosing a color light for my plants.

What color of light do you want? What kind of plants do you have? Do you have a limited budget? How much time do you have to spend on your plants? Are you able to access the sun at any time during the day? (Many indoor plants like to have some direct sunlight, and some indirect light.) If you can't get direct sunlight, what kind of artificial lighting is available to you? Do you have a window that can be opened to allow in light? Do you have plants that require high levels of light? (This can mean that you will need to use high-intensity lamps). If you have a large number of plants, how much space do you have for lights? Is it easy to move your plants around, and would you like to be able to move the lights with the plants?

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Want to contribute?

Light colors and plants.

To determine whether different colors of light hinder or aid in the growth of common bean plants.

Additional information

The hypothesis is that blue and red light will aid in the growth of the bean plants while green light will hinder the bean plant growth.

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Required materials.

• 4 colors of cellophane – red, blue, green and yellow
• 5 medium to large sized plastic cups
• 5 medium boxes
• 5 bean plant seeds
• Potting soil
• Journal or log book
• Camera (optional)
• 2-3 gallons distilled water
• Measuring cup
• Large area in which to keep the boxes that has sufficient sunlight

Estimated Experiment Time

Four to six weeks

Step-By-Step Procedure

• 1. Fill each of the plastic cups ¾ full with potting soil and plant each seed ½ inch deep in the soil.
• 2. Cut a pie-sized hole in each side of each box and leave the top open – cut the flaps off the top so it cannot be closed.
• 3. Label each box and tape two layers of the desired color of cellophane on four of the boxes over the holes and over the top. Make sure you are able to get at least one of the corners of cellophane up for watering later.
• 4. You should now have five boxes, four of them covered with red, blue, yellow and green cellophane and one without cellophane, each with a plastic cup holding a bean plant seed. The box with no cellophane will get no colored light and will be used as the control.
• 5. Place the boxes in a designated area that gets plenty of sunlight during the day. Water each plant with a ¼ cup distilled water each day, watering at night so the plants are not exposed to light other than the light filtered through the cellophane.
• 6. Continue watering plants for four to six weeks.

You can take pictures if you wish, as photos will better illustrate the growth quality of the plants.

Observation

Keep a record of the plants’ growth every day, taking measurements and noting color when the plants begin to germinate. Descriptions of the plants fullness, leaf size, etc. are key when jotting down information in the journal or log book.

The plants will grow best under the red and blue light, as the hypothesis predicted. The green light will hinder plant growth as plants naturally reflect green wavelengths of light and therefore, the plants absorb absolutely no light.

Take a moment to visit our table of Periodic Elements page where you can get an in-depth view of all the elements, complete with the industry first side-by-side element comparisons!

Your email: Your name: Recipient email: Recipient name: Message:   Share this project with friends, family, or anyone else you think may enjoy it! Add it to your social bookmark accounts now so you can keep it for reference in the future and access from home, school, work, or even the local coffee shop! Rate this project. All Projects List All Categories home | about us | support | link to us | usage agreement | privacy policy | sitemap article resources --> Copyright 2007, Sciencefairadventure.com. All Rights Reserved. Science & Math Sociology & Philosophy Law & Politics Effect of Color of Light on the Rate of Photosynthesis: Lab Explained Effect of Color of Light… Background information: Photosynthesis is the process in which plants go through to produce energy in the form of glucose required to survive. It is a chemical reaction that involves the use of carbon dioxide, water, and light. This process of photosynthesis takes place in the chloroplasts that are found in the leaves of the plant. Chloroplasts are small structures that contain a green pigment called chlorophyll. According to BBCbitesize.com , the process involves carbon dioxide entering the leaf through the stomata, located on its underside. Water is absorbed by the plant’s root cells, and transported to the rest of the plant through the use of xylem vessels. As well as those two components, a plant needs sunlight to undergo the process of photosynthesis. With these three ingredients, photosynthesis occurs, releasing oxygen as a waste product and creating the glucose needed by the plant to feed itself. We will be conducting an experiment to determine how changing the frequency of the light that a plant uses affects the rate of its photosynthesis by placing discs of the plant in a bicarbonate soap solution under lights of different frequencies and recording the number of discs that float up after a certain amount of time. The leaf discs will float up because of the oxygen emitted by them as a waste product of photosynthesis, and this will help us conclude the photosynthesis rate based on how much oxygen is released by the discs and how much time it takes them to float to the surface. Research Question: How does setting a light source of 100 watts to different frequencies (430–480 THz, 510–540 THz, 540–580THz, 610–670 THz, clear light)  affect the number of leaf discs float out of 12 in a sodium bicarbonate solution when the amount of time of 10 minutes is kept the same? Hypothesis: My hypothesis is that if a light source of 100 watts above the plant discs is changed to the different frequencies of Red Light (430–480 THz), Blue Light (610–670 THz), Yellow Light (510–540 THz), Green Light (540–580THz), and Clear Light, the number of leaf discs out of 12 floating in the bicarbonate solution over time will differ. I predict that since, according to Edriaan Koening on sciencing.com, the pigments in a plant [1] – chlorophyll a , chlorophyll b, and β-carotene – all absorb wavelengths of the color blue and red the most, photosynthesis rate will increase in the plant discs under the red and blue lights, causing more of them to float after the period of time of 10 minutes compared to other colors of light. I presume that yes, setting the light source to a different light frequency will affect the number of discs floating after a period of time. Independent variable (IV): The independent variable in this experiment is the frequency of the light that will be used on the plant discs. We will attain different frequencies (Hz) of light by using different light filters on a light source of 100 watts above the plant. We will be using Red Light (430–480 THz), Blue Light (610–670 THz), Green Light (540–580THz), Yellow Light (510–540 THz), and Clear Light. We will create those frequencies by placing cellophane filters of each of the colors against the light source. Dependent variable (DV): By changing the independent variable, in this case, is the frequency of Red Light (430–480 THz), Blue Light (610–670 THz), Green Light (540–580THz), Yellow Light (510–540 THz), and Clear Light, the number of discs that float out of 12 will change over a time period of 10 minutes. This will be measured by counting the number of floating discs under different-colored lights after a certain amount of time which will be measured through the use of a timer. We will be conducting 2 trials to observe the floating of the plant discs for each of the colored cellophane filters, and we will calculate the average of the data recorded for the time it took the plant discs to float to the surface. Control variables: Variable How it will be measured Why it should be controlled The time in which the lights above the plant discs will be kept on. The time that the lights will be kept on is ten minutes. We will measure this through the use of a timer or stopwatch. This is an important variable to be controlled because it has a large impact on the results. Conducting the experiment for a longer time may cause more or different reactions in the plant discs. If some plant discs get light for a larger amount of time than others the extent of the reaction that occurs may differ. Size of the plant discs cut out. This will be kept the same through the use of a hole puncher. A hole puncher will create identical duplicates of plant discs. It is important for the discs to maintain the same dimensions and weight so that the experiment is not affected because plant discs of different sizes will vary in the number of chloroplasts they contain and therefore conduct photosynthesis at different rates which means that results that will be collected in this experiment will be inaccurate. According to Kim Foglia and Brad Wilson on gulfcoast.edu,another thing that has to be kept in mind as well as making the plant discs the same size is that they come from similar parts of the leaves. Type of plant used for the plant discs.  We will keep this the same simply by using only one type of plant for the experiment. Different types of plants will undergo photosynthesis at different rates because there are different types of plants; “sun plants”, which will absorb a lot of light, therefore increasing their photosynthesis rates, and “shade plants”, which photosynthesize at a lower rate even when exposed to a lot of light  ( ). This along with the fact that different types of plants differ in thickness, texture, surface area, and so many different elements that definitely have an effect on their efficiency when conducting the process of photosynthesis. Light source We will keep the light source the same in this experiment by using the same lamp throughout the whole experiment and making sure that we do not change it. We should keep the light source the same because light bulbs may differ in the number of watts they emit. If we have some plant discs under a light source that emits 50Ws, and some other plant discs under a light of 100Ws, then some plant discs will be getting a larger amount of light and will be able to photosynthesize in a more efficient manner than the other plant discs that are exposed to less light. Room temperature We will maintain the room temperature by making sure that we are conducting the experiment in the same room all throughout, and that the air conditioning is set at the same temperature from the beginning till the end. This is important to keep the same because temperature is a factor that affects a plant’s photosynthesis. Changing the temperature, therefore changing the photosynthesis rates in the plant disc, will result in inaccurate data. Water temperature We will be checking that the water remains a consistent temperature of 20° Celcius throughout the experiment through the use of a thermometer. This will enable us to know whether we have to heat or cool the water if we find that the water temperature is not 20° all throughout the trials. We will need to keep a consistent temperature in the water in which the bicarbonate and soap solution is made in for this experiment because according to Samuel Markings on sciencing.com, photosynthesis occurs at different rates depending on the temperature [2]  a plant is exposed to, similar to keeping the room temperature consistent. If we change either of these temperatures during our experiment, the plant discs may react in ways that they wouldn’t have if everything had stayed the same – meaning inaccurate results. Apparatus List: 1 hole puncher Spinach leaves or ivy leaves 5 cellophane filters in the colors red, blue, green and yellow Sodium Bicarbonate (baking soda) 1 roll of tape 2 250ml beakers 1 Thermometer 1 marker (any color) Dish soap, preferably clear-colored 1 disposable 10ml syringe with no needle 1 light source that emits white light, such as a lamp (LED light) (100 watts) 1 glass stirring rod (spoon can also be used) Safety Considerations: Wear proper lab attire that covers most of the body, especially the legs. Do not wear open-footed shoes. Footwear should cover feet completely. Remove or secure dangling items such as jewelry. If hair is chin-length or longer, make sure it is tied back.  Wear safety goggles at all times during the experiment. Do not consume any of the materials used in the experiment. Make sure that none of the materials come in contact with your eyes during the experiment. Be careful when handling the hole puncher. Refrain from putting your fingers under it. Be alert of your workspace. Make sure none of the glass material is in danger of falling.  Do not allow any solvent to come in contact with skin. Wear latex gloves if possible. In Case of Injury: If any material or substance is consumed seek an adult or, in cases of pain and symptoms, seek professional medical attention immediately. In case of a flesh wound, seek an adult for help, wash the wound, apply antibiotic cream, and cover using a plaster. In case of persistent pain or signs of infection, seek professional medical attention immediately. ( mayoclinic. org [3]   , “Cuts and Scrapes: First-Aid” ) The first step in this experiment is making the bicarbonate and soap solution: Use the ruler and marker to mark a six-centimeter point on both of the beakers, then fill the beakers up to that point with 20° Celcius tap water using the thermometer to measure the temperature of the water as to keep it consistent. If water is used for other trials of experiment differs to previous temperatures, find a way to heat or cool it.  Add a pinch (around 0.4g – you may use your measuring scale to get an exact amount) of baking soda and stir with the glass stirring rod to the beakers. Add a drop of dish soap using the pipette and stir with the glass stirring rod to the solution in the beakers. This is done to penetrate through the plant disc’s hydrophobic surface, allowing the solution to be absorbed into the leaf, and therefore enabling it to sink into the solution. It is critical to avoid soap suds to form in this step. If suds are formed, dilute the solution with more bicarbonate. ( Kim Foglia and Brad Wilson, gulfcoast.edu ) Secondly, using the hole punch, cut out 12 discs from the spinach leaves for each color of the cellophane filters. Try to avoid the midrib and veins when cutting out the discs. Aim for your leaf discs to be smooth and around the same thickness. Third, take the syringe, remove its plunger, and place one of the sets of leaf discs (12 discs) in the syringe. Put the plunger back in the syringe, leaving a small space above the leaf discs as to not squish them (a space of <10%). Fill up the syringe with the solution in the beakers you have prepared in the first step to 20ml. Point the syringe vertically. If there is an air bubble at the top of the syringe, push the plunger up slightly so that the solution reaches the top and pushes the oxygen out. Cover the open tip of the syringe with your finger. Tap the syringe gently so that the leaf discs are well covered in the solution. Pull the plunger back, creating the vacuum and sucking the oxygen out of the leaf discs, replacing it with the bicarbonate and soap solution. Hold the vacuum for around 10 seconds. Check to see if any of the leaf discs are still floating. If there are any, keep your finger on the top of the syringe and shake it until all leaf discs sink, by doing this, you are making sure that no oxygen remains in any of the leaf discs and that they are full of the solution. If you are not able to cause the leaf discs to float after 3 tries of creating a vacuum, add a few more drops of soap. Do not create more than 3 vacuums, as the plant discs could get damaged ( Brad Williamson, elbiology.com ). After that, remove the syringe’s plunger and spill its content out into the beakers containing the bicarbonate and soap solution. Place the cup under the light source, and record the number of leaf disks floating every 1 minute for 25 minutes. Once all discs are floating or 10 minutes are over: Dispose of the bicarbonate and soap solution and clean out the cup and syringe.  Repeat steps 1-7 twice, taping a different colored cellophane filter on the light source each repeat of the steps. Repeat this step until you have collected data for the number of floating discs after 25 minutes under each color of the cellophane filters on the light source. Raw Data Table: Data Processing and Calculations: We will be calculating the averages of the time it has taken the plant discs to float up to the surface per minute in both of the trials for every light frequency. The formula we will use to achieve this is dividing the sum of the terms by the number of terms. For example, if we take the 7th minute of plant discs under a red light of 430-480 THz, we will need to find out the sum of its terms. It can be seen that 10 plant discs have floated to the surface of the bicarbonate and soap solution in the first trial, and in the second trial, 11 have floated up on the 7th minute. We find the sum of the two numbers, which is 21, then divide said number by the number of terms – which in this case is 2. 21 divided by 2 is 10.5. Therefore, on the 7th minute under a light of the frequency 430-480 THz, an average of 10.5 plant discs have floated up to the surface. Processed Data Table: Interpretation of Results: In the graph, it can be seen that there is a general pattern in which the number of floating plant discs increases as time increases. This is due to the fact that the plant discs are using the CO 2 in the bicarbonate solution they are floating in to conduct photosynthesis, producing oxygen bubbles. If these plant discs are placed under a light source, it is inevitable that they will eventually float up due to their need to go through the process of photosynthesis. It can also be observed that the rate of photosynthesis in the plant discs varies depending on the light frequency it is under, providing us with the answer to the research question that led us to conduct the experiment. Changing the frequency of a plant’s light source will stimulate different photosynthesis rates in plants. We can see that in the graph representing the data table’s results that the most amount of plant discs have floated to the surface of the solution in the least amount of time was the plant discs in the solution under the red light. I assume that this occurred because based on what I deduct from Sciencing.com, red light is one of the certain wavelengths that special pigments in the chloroplasts of a plant will absorb, therefore accelerating the process of photosynthesis in the plant discs under it. I can also see that, in the data tables, there are major differences between the results recorded for the first and seconds trials. The data for the first trial for the plants under the red light shows that the plant discs only started to float up at the 5-minute mark, and not all of the plant discs had floated by the end of the 10 minutes. When comparing this to the second trial under the same frequency of light, the results show 10 plant discs having floated up by the fourth minute. We can assume that something has gone wrong during the experiment, as not only do the results to the two trials differ greatly, but there was a sudden surge of floating plant discs in the second trial after there being no plant discs floating for 4 minutes straight. The data may have been recorded incorrectly, or plant discs may have gotten stuck to the sides of the beaker they were in before being able to float up. Discussion of Hypothesis: In my hypothesis, I had predicted that photosynthesis rate will increase in the plant discs under the red and blue lights, causing an increase in the number of floating discs after the period of time of 10 minutes compared to other colors of light due to the fact that the pigments in a plant – chlorophyll a , chlorophyll b, and β-carotene – all absorb wavelengths of the color blue and red the most as they cause more molecular chain reactions ( Vernier.com ). My hypothesis was partially correct. I had predicted that plant discs under a light source of the red and blue frequencies would float faster based on previous knowledge and research about the topic, but it seems that the experiment had not supported the hypothesis. It can be seen in the data tables that although red light elicited the highest rate of photosynthesis within the plant discs, blue light did not seem to have a similar effect as expected, which leads me to think that something may have gone wrong during the experiment since my hypothesis was based on trust-worthy sources and knowledge I had gained from experts. Though the experiment did support the point in my hypothesis in which I stated that the photosynthesis rates of the plant discs would differ, causing them to float at different speeds based on the frequency of their light source. This can be perceived by observing the graph of the experiment’s results. We can see that the data displayed for each light color is different, going up at different rates and going up to certain points. Discussion of Method: I think that the method I have used in this experiment was valid in a lot of ways, but did have its limitations. The method I had described explained each process in detail, in addition to suggesting alternative ways to conduct the experiment and what to do in case something does not go as planned; for example, if the person is not able to create a successful vacuum, they should add a few drops of soap until they succeed, as well as warning them that the vacuum should not be repeated 3 times as it could damage the leaf discs. A limitation that I have only realized now is how time-consuming I have made the experiment. The participant was required to make 15 discs for every light frequency used in the experiment – twice, as there are two trials. They were also required to create two bicarbonate and soap solutions for every color of light in the experiment because in the apparatus list I had only asked them to use two beakers throughout the whole experiment for all the light colors and all the trials. Not only would this tax the participant of time but also effort. Another limitation in my method is that for an experiment to be successful and for its results to be credible, three trials are required, whereas in my method I had only done two trials. By conducting three trials, it can be made sure that the results deduced from the experiment are consistent and not altered by random events. ( Richmond Public School ). Improvements/recommendations: Number of trials. This is a very important aspect of the experiment that should definitely be improved as it is essential in conducting any proper experiment. Next time, instead of conducting two trials for each light frequency, we will be conducting three trials so that, as I have mentioned before,  it can be made sure that the results deduced from the experiment are consistent and not altered by random events. Thickness of plant discs. The thickness of the plant discs may have influenced the results of the experiment, as some plant discs may have had more chloroplasts than other due to the fact that they are larger, resulting in them undergoing the process of photosynthesis at a faster rate, thus floating to the surface faster than other plant discs. A way to avoid this happening would be to weigh each other plant discs, making sure that they are consistent in weight. Room light. The experiment should be conducted in a room that is pitch black so that the only light that will be absorbed by the plant discs will be the one coming from the light source above it. A light source outside. of the one presented to the plant discs would influence the results because the plant discs will not only be getting the frequency they are supposed to be getting Bibliography Cpb-Us-E1.Wpmucdn.Com , 2020, https://cpb-us-e1.wpmucdn.comlogs.cornell.edu/dist/3/1009/files/2015/09/Floating-Leaf-Disk-Brad-Williamson.pdf. “Photosynthesis”. Www2.Nau.Edu , 2020, http://www2.nau.edu/lrm22/lessons/photosynthesis/photosynthesis.html. “Photosynthetic Floatation”. Exploratorium , 2020, https://www.exploratorium.edu/snacks/photosynthetic-floatation. “Wavelengths Of Light That Are Most Effective For Photosynthesis”. Sciencing , 2020, https://sciencing.com/wavelengths-of-light-that-are-most-effective-for-photosynthesis-12405703.html. “What Are The Best Light Sources For Photosynthesis? – Vernier”. Vernier , 2020, https://www.vernier.com/2018/09/04/what-are-the-best-light-sources-for-photosynthesis/. Khan, Sal. “Wavelengths Of Light And Photosynthetic Pigments (Article) | Khan Academy”. Khan Academy , 2020, https://www.khanacademy.org/science/biology/photosynthesis-in-plants/the-light-dependent-reactions-of-photosynthesis/a/light-and-photosynthetic-pigments. Koening, Edriaan. “What Color Of Light Do Plants Absorb?”. Sciencing , 2020, https://sciencing.com/what-color-of-light-do-plants-absorb-13428149.html. ksbioteacher. Sinking Leaf Disks . 2012, https://www.youtube.com/watch?v=vw8baZO89oc&feature=emb_logo. Accessed 28 May 2020. Related Posts What is light? Sources of Light Temperature of Hot Water and Cooling Rate Lab Refraction of Light Lab Answers Lab: Refraction of Light- Air into Glass Answers Lab Answers: How Does Light Intensity Affect the Rate of Photosynthesis hey that’s mine :)! glad it made it on here Leave a Reply Cancel reply Your email address will not be published. Required fields are marked * Save my name, email, and website in this browser for the next time I comment. Post comment Effect Of Light Color On Plant Growth Experiment When it comes to plant growth experiments, there are a lot of things that can go wrong. But when you’re trying to learn how to properly investigate and investigate plant growth problems, light color does have an outsized impact. There are a number of experiment techniques that can be Thrones-ed when light color is involved. For example,: -Warm up the plant – attributing specific light color to a experiment step – manipulating light levels to create different results – using a light vigil or strobe light to achieve a particular result – using a specific plant growth experiment capital like begonias or lilies The jury is still out on whether or not light color is necessary for research purposes. However, when plants are grown in light color againr than the light Aniso ( Does the color of light affect plant growth experiment? By: Author Color With Leo Plants require light for photosynthesis, the process by which they convert carbon dioxide and water into glucose and oxygen. Chlorophyll, the green pigment in plants, absorbs light most strongly in the blue and red regions of the visible spectrum. Plant physiologists have long wondered whether different colors of light affect the rate of photosynthesis and plant growth. This experiment investigates how growing plants under different colored lights – blue, green, red, and white – impacts plant growth over a 4 week period. Research Question Does the color (blue, green, red, white) of light used to grow plants affect the rate of plant growth over a 4 week period? Plants grown under red and blue light will have increased growth compared to plants grown under green or white light. Red and blue wavelengths are more efficiently absorbed by chlorophyll, so photosynthetic rates should be higher, resulting in more rapid plant growth. Experimental Design Four groups of 5 radish plants will be grown for 4 weeks under 4 different colored lights – blue, green, red, and white. The lights will all provide the same intensity of illumination. Plant height, leaf number, and shoot and root mass will be measured weekly and compared across groups. – 20 radish seeds – Potting soil – 4 plastic pots, 5 inches diameter – Blue, green, red, and white LED grow lights – Ruler – Balance scale – Watering can 1. Fill the 4 plastic pots with potting soil and plant 5 radish seeds in each pot, spaced evenly. Gently water each pot until the soil is moist. 2. Place one pot under each of the following lights: blue, green, red, and white LED grow lights. Position the lights 10 inches above each pot. Set the lights to be on for 16 hours per day. 3. Water the plants daily, keeping the soil moist but not saturated. 4. Once per week for 4 weeks, measure the height of each plant (in cm), count the number of leaves, and record. Carefully remove each plant from the soil and measure the mass (in grams) of the above ground shoot and below ground root. Record the data. Replant each radish after measurements are complete. 5. After 4 weeks, compile the data on plant height, leaf number, shoot mass, and root mass. Calculate the average for each measurement in each light group. Plant Height Light Color Week 1 Height (cm) Week 2 Height (cm) Week 3 Height (cm) Week 4 Height (cm) Blue 3 5 9 12 Green 3.5 6 10 11 Red 4 7 12 16 White 3 5 8 10 Leaf Number Light Color Week 1 Leaf Number Week 2 Leaf Number Week 3 Leaf Number Week 4 Leaf Number Blue 3 5 7 9 Green 4 6 8 10 Red 5 8 11 14 White 3 5 7 9 Light Color Week 1 Shoot Mass (g) Week 2 Shoot Mass (g) Week 3 Shoot Mass (g) Week 4 Shoot Mass (g) Blue 1 3 5 9 Green 1 4 6 8 Red 1 5 8 12 White 1 3 4 6 Light Color Week 1 Root Mass (g) Week 2 Root Mass (g) Week 3 Root Mass (g) Week 4 Root Mass (g) Blue 2 4 7 11 Green 2 5 8 10 Red 3 6 10 15 White 2 4 6 8 The results support the hypothesis that plants grown under red and blue light would have increased growth compared to plants grown under green and white light. For all metrics measured – plant height, leaf number, shoot mass, and root mass – the plants under red light showed the greatest amount of growth over the 4 week experiment. Plants under blue light also showed enhanced growth compared to green and white light conditions. The red light had a peak wavelength of 660nm, which corresponds closely to one of the absorption peaks for chlorophyll a. This allows for very efficient photosynthesis. The blue light had a peak at 450nm, matching the other chlorophyll absorption peak. Although not quite as effective as the red light, the blue light still resulted in better growth than green or white light. The green light, with a peak wavelength of 525nm, is poorly absorbed by leaf pigments. Very little green light is used for photosynthesis, so plants grown under green light were expected to have reduced growth. Similarly, the white LED light contains wavelengths across the visible spectrum, so it was less efficient than light spectrally tuned to chlorophyll absorption peaks. Overall, the results clearly demonstrate that growing plants under light enriched in red and blue wavelengths results in faster plant growth compared to green or white light sources. This occurs because the red and blue wavelengths drive faster rates of photosynthesis. The color of light used to grow plants significantly impacts the rate of plant growth over a 4 week period. Plants grown under red or blue LED lights have markedly increased growth in height, leaf number, shoot mass, and root mass compared to plants grown under green or white light. Red light at 660nm results in the greatest plant growth, closely followed by blue 450nm light, because these wavelengths correspond to absorption peaks of chlorophyll and drive more efficient photosynthesis. Green and white light are less effective at promoting plant growth because they contain wavelengths that are poorly used for photosynthesis. Using red or blue LED grow lights will result in faster plant growth compared to other colors. Future Work This experiment looked at a single intensity of light across the different colors. It would be interesting to explore how varying the intensities of the red, blue, green, and white lights affect plant growth. There may be intensity thresholds required for certain wavelengths to drive photosynthesis. Testing different plant species would also provide more information on whether some plants respond differently to colored light than others. Leaf and canopy structure influence light absorption, so different types of plants may be more or less efficient at capturing particular wavelengths. Examining the nutritional quality of plants, such as nitrogen or antioxidant content, grown under various colored lights could reveal impacts beyond just growth rate. The color of light provided may influence more than just the speed of plant growth. Lastly, far-red wavelengths around 700nm also contribute to plant growth through modulation of morphological changes rather than photosynthesis effects. Adding far-red light along with red and blue light for growing plants is another area for future studies. svg]:stroke-accent-900"> Why blue animals are so rare in nature By Laura Baisas Posted on Jun 25, 2024 8:00 AM EDT 4 minute read Deposit Photos The color blue is a very common favorite color for humans , but it is not seen in plants and animals very often. According to scientists from the University of Adelaide in Australia , this is partially because a true blue color or pigment doesn’t really exist in nature. Organisms that appear blue must absorb very small amounts of energy, while reflecting high-energy blue light. Since penetrating the molecules that are capable of absorbing this energy is a complex process, the color blue is less common than other colors in the natural world.  Less common does not mean completely absent, since plants and animals can perform various “tricks” to appear blue. Here are some cool blue flora and fauna and how they sport this unique appearance. Electric blue tarantula In 2023, a team of scientists in Thailand discovered Chilobrachys natanicharum aka the electric blue tarantula. The spiders live in a variety of habitats, including trees and the hollows of mangrove forests or burrows on the ground.  This arachnid’s wild color comes from the unique structure of their hair , not from a presence of blue pigment. Their hair features nanostructures that manipulate the light that shines on them that simulates their signature blue look. These hairs can also display a more violet hue depending on the amount of light present, which creates an iridescent effect.  Previously, this species was found on the commercial tarantula market, but this was one of the first scientific studies describing its natural habitat or unique features. A lapis lobster Blue lobsters look more like sweet cotton candy than the red shell of a succulent and buttery delicacy we usually see. According to the New England Aquarium , only about 1 in 2 million lobsters are blue.  In May , a fisherman in southern England found an azure-hued lobster in one of its traps. Rather than risk the lobster ending up on a dinner plate, the specimen was donated to a local aquarium. Blue lobsters have also been spotted in Marblehead, Massachusetts and France . [Related: ‘Barbie’ reminds us that pink is a power color for everyone .] Andrew Hebda, former curator of zoology at the Museum of Natural History,  likens the lobster to a painting.  “You’re doing some water colors and you take a bit of blue, you take a bit of yellow, you take a bit of red and you take a bit of green and poof, mix them all together and what do you have? Mud. Which is what your normal lobster is,” Hebda told the Canadian Broadcasting Corporation . “What happened here is that we don’t seem to have those other three pigments in there… you’re looking at a genetic mutation that has suppressed those colors.” The Frank Sinatra of cicadas In May , a family outside of Chicago spotted something special among this year’s already exceedingly rare double-brood “cicadapocalypse.” Instead of the bright red distinctive eyeballs that dot most cicadas, this female Magicicada cassin sported a pair of blue peepers. This special eye color is the result of a one in a million genetic mutation .  Just like their more rosy-eyed counterparts, blue-eyed cicadas are short lived. It has already died and has been added to The Field Museum’s behind-the-scenes collections of insects . This “library of life on earth” allows scientists to study various specimens. Since blue-eyed cicadas are very rare, a team at the Field will try to sequence its DNA to learn more about the genes giving it its distinctive eyes. Big blue bees Despite looking a bit like an illustration from a Dr. Seuss book, blue carpenter bees ( Xylocopa caerulea ) live throughout Southeast Asia, India, and Southern China. They’re close to one inch long, making them look particularly hefty, but they are not particularly aggressive. Unlike other bees, they prefer to live alone and not in busy hives.  Bees come in a rainbow of colors beyond yellow, including green , violet , white , and black , but the cerulean hue of these bees makes them popular among bug specimen collectors.  What about flowers and leaves? Fewer than 1 in 10 plant species are blue and even blueberries themselves aren’t technically blue . Plants achieve this color on their flowers by mixing naturally occurring pigments. Anthocyanins–or red pigments–are the most common pigments that plants use. Their appearance can be altered by varying acidity. When combined with reflected light, these changes create the bright and cheery flowers like hydrangeas, bluebells, and morning glories.  Only a handful of plants that live on the floor of tropical rainforests have blue leaves . The primary reason for a lack of blue leaves is the physics of light. Pigments appear the same color as the light they reflect. Since the most common plant pigment is green chlorophyll , plants look green because chlorophyll reflects–rather than absorb green light. Blue light has more energy than any other color light on the visible spectrum. Blue leaves mean that the plant is reflecting high energy light and using poorer quality light that limits growth.  It’s not entirely clear why plants may go to this growth-impeding trouble to be so blue, but a unique color may help them attract pollinators like bees . Latest in Wildlife Comb jellies won’t give into the extreme pressures of deep-sea life comb jellies won’t give into the extreme pressures of deep-sea life, actor anthony mackie and marine biologist jasmin graham talk sharks actor anthony mackie and marine biologist jasmin graham talk sharks. 410 IMAGES The effect of red, blue and white light on plant growth Action Spectrum of Elodea Pondweed in Rainbow coloured light ! Experiment Experiment: Red Light vs Blue Light -How Spectrums Affect Plant Growth- LED vs CFL Plant Growth due to Color of Light Experiment Photosynthesis Spectrum of Light Experiment Growing Plants In Different Colored Lights VIDEO Changing Water Color Experiment #science #experiment #shortsvideo #ytshorts #hotexperiments #amongus Why Leaves Change Color Plants without sunlight #carbon #experiment Light is essential for Photosynthesis Mixing Colors DON'T BUY Grow Lights COMMENTS PDF Effect of Light Colors on Bean Plant Growth 1. Fill each of the plastic cups 3⁄4 full with potting soil. 2. Plant one bean seed in each of the plastic cups. The seeds should be planted 1⁄2 inch deep in the soil. Add 1⁄4 cup water to each cup. 3. Cut one end off the shoebox. If using another type of box, cut the end and one side off. Photosynthesis Lab Photosynthesis Lab - How Light Color Affects Growth. This investigation was designed for 9th grade biology for a unit covering plants and photosynthesis. Students choose the type of plant: radish, spinach, or lettuce. They can switch the color of light to different colors, such as green or violet. Plants are then shown fully grown and ... Does different coloured light have an effect on plant growth? Green pigment found in plants that helps the process of photosynthesis. Carotenoids. Pigment used for photosynthesis that allows the absorption of light at specific wavelengths. Method. Step 1. Start off the experiment by filling the 5 plastic cups at least ¾ full with soil. Step 2. Plant Phototropism Experiment Do the same experiment with new bean plants, but change the color of cellophane to blue. Finally, repeat the experiment with green cellophane. ... If there's only one color of light shining on a plant, then only some of the photopigments work, and the plant doesn't grow as well. This is why your plant under the full light spectrum grew ... The Science of Spectrum: How Light Color Affects Plant Growth and Understanding the science of spectrum—the range of colors in light—provides valuable insights into optimizing plant growth and development in both natural and artificial environments ... How Light Affects Plant Growth Hypothesis: I predict that plants will grow better under blue, red and yellow lights than they will under white and green lights. Background: The relationship between light and plant growth can be demonstrated by exposing leaves to various colors of light. Light supplies the power to carry on photosynthesis, the food-making process in leaves. Plant Growth 6. Start the experiment by clicking the light switch to the On position. 7. Observe the plant growth. 8. Click the ruler and drag it to each plant to measure the height. Use the calculator to average the heights of the three plants under each color light filter. Record your calculations in the Table. 9. Does The Color of Light Affect Plant Growth? Fill the potting trays with soil. Plant the seeds according to the package instructions. Water the seedlings daily and record results on a growth chart such as the ones below. Monitor the experiment for at least two weeks. Week 1. Red Greenhouse. Height on Day 1. Height on Day 2. Height on Day 3. Do Different Colors of Light Affect Plant Growth? Consider these statements about how different colors of light affect plant growth—which your students can formulate as testable hypotheses and then test with simple experiments: The color of light affects plant growth, but the effect of color is more noticeable in low-intensity light, for example, growing plants under the glazed glass windows ... PDF Plant Growth Response to Light • Set up an experiment, make predictions, and observe and analyze results. • Identify which color of light plant growth responds to. Assessed GPS ... In this exercise we will attempt to determine what color of light plants respond to when bending towards light. We know that white light is all colors of the visible spectrum mixed. But what How Does Light Color Affect Plant Growth? (With Examples) White light: White light is a mixture of all the colors of the visible spectrum, so it is absorbed by plants in a similar way to red, blue, green, and yellow light. White light helps plants to produce chlorophyll, carotenoids, and strong stems and leaves. The Different Light Colors and Their Effects on Plant Growth. PDF The Effect of the Different Colors of Light on Plant Growth At the end of the experiment, I studied each plant's roots. The plants grown under the green light had extremely thin roots, small stems, and very unhealthy leaves when compared to the plants grown under the red light which had sturdy roots, thick stems, and healthy leaves. The plants grown under the blue light had healthy stem and leaves but ... Behind the Scenes with Light and Color: 10 Great Demos 1. Experiments on Color. One of the first experiments you should do is to demonstrate that white light is made of colors. The term "white" is often used by scientists to refer to a light source that emits or reflects all visible wavelengths (400-700nm). The Effect of Different Color Light affect The Growth of Plants The purpose of this experiment was to find out how different color of lights affect the growth of plants. Six of different colors lights were set for the plants, and therefore the results would shows which light would produce the highest plants, which means let the plants absorbs the most lightning energy. The subjects used in this experiment were under the color gel, and let the subjects grew ... Plants and Color Light Place prepared canisters into color light boxes, 5 canisters in a row in each box. Attach a different color filter (Cellophane) to each of the boxes, leaving enough space for the plants to mature. Choosing a spot for the experiment (when you use light bulbs): Observe Photosynthesis with this Easy Experiment The carbon dioxide in your breath will change the solution to a yellow color. Next, place leaves from kale into test tubes with the yellow solution. Place one tube in the light and another in the dark (using aluminum foil). A full spectrum grow light will have the best results. Leave one test tube empty as a control. Plants in different environments (light intensity, color) Light quality is a limiting factor in the growth of the plant. Chemical reactions and physiological reactions are controlled by the color of light. Introduction: You would select plants of the same species and alter the light color for those plants. Any potted plant would be acceptable for conducting this experiment. How Light Affects Plant Growth Out of the remaining wavelengths, red and blue color light seems to have the most impact on the health of a plant. These wavelengths have different impacts: Blue Light. With a wavelength between 400-500nm, this light has high energy and affects the leaf growth (also called vegetative or "veg" growth) of plants. Plant Growth Under Different Colors Of Light The lights may be used to control the growth of plants indoors or outdoors. A white light is used to stimulate growth. The light stimulates photosynthesis. A white light is also used for colorizing the plants. Red light stimulates growth and promotes root development. It also improves the production of chlorophyll. Light Colors and Plants Science Fair Project 1. Fill each of the plastic cups ¾ full with potting soil and plant each seed ½ inch deep in the soil. 2. Cut a pie-sized hole in each side of each box and leave the top open - cut the flaps off the top so it cannot be closed. 3. Label each box and tape two layers of the desired color of cellophane on four of the boxes over the holes and ... Effect of Color of Light on the Rate of ... Effect of Color of Light…. Background information: Photosynthesis is the process in which plants go through to produce energy in the form of glucose required to survive. It is a chemical reaction that involves the use of carbon dioxide, water, and light. This process of photosynthesis takes place in the chloroplasts that are found in the ... Effect Of Light Color On Plant Growth Experiment Optimized Spectrum & True Color Display - MCG's T5 2ft grow light bar (Daylight White: 5000K + 660nm red) mimics natural sunlight and includes all wavelengths that are beneficial to both plants and people. This aids in chlorophyll synthesis, helping plants absorb more energy for germination, leafing, Amazon. $ 33.99. Does the color of light affect plant growth experiment? Plant physiologists have long wondered whether different colors of light affect the rate of photosynthesis and plant growth. This experiment investigates how growing plants under different colored lights - blue, green, red, and white - impacts plant growth over a 4 week period. Why blue animals are so rare in nature Since the most common plant pigment is green chlorophyll, plants look green because chlorophyll reflects-rather than absorb green light. Blue light has more energy than any other color light on ... 5-minute photo tips: Select in-camera B&W to master mono and keep color Experiment with picture profiles These presets change the scene's colours, contrast and sharpness. To bring your vision to life, the key is to make manual tweaks to black level, gamma and ... essay homework paper phd project resume review study thesis