How Does Colored Lights Affect Plant Growth Presentation

If the light shining over a plant has a shorter wavelength, the plant will grow faster than a plant under a light with a longer wavelength because it is under a light with more energy.

Why use sugar snap pea plants?

• Easy to grow (does not need high maintenance)
• Not too huge in size
• Grows quickly (were able to fully grow in a few weeks)
• Easily accessible

Relevance to today

• can be used to find best quality of light for growing
• eg. farming, gardening
• can be used to slow down/speed up growth for observation in experiments
• can be used to decrease need for extra resources/help with scarcity
• to determine if growing plants using artificial light is more efficient/effective than growing plants with sunlight as the light source

Discussion:

• colored lights do affect plant growth

Green:

Orange/Red:

White:

Blue:

• similar growth rate to blue but slower
• white light composed of entire visible spectrum ROYGBIV
• therefore: plants able to absorb all the optimal wavelengths for photosynthesis
• however: also absorbs all the wavelengths that caused less growth

• the orange and red lights had similar growth rates
• orange used was very red (as w/ purple b/c cellophane paper)
• absorbed very well by chlorophyll, should have been more than green
• large red-orange range of light in sun --> evolutionarily beneficial to be able to absorb more
• (best QUANTITY)

• 3rd highest, should have been one of lowest, chlorophyll reflects green light
• maybe the green light used:
• absorbed by carotenoids/accessory pigments
• had a wavelength closer to blue, not the one reflected by plants --> QUALITY close to blue's

• blue wavelength --> optimal energy for photosynthesis
• photosynthesis will occur more quickly w/ the right amount of energy
• photosynthetic pigments can absorb this wavelength most, most beneficial for the plant to perform photosynthesis
• best QUALITY and a high QUANTITY (penetrates atmosphere well)

SCIENCE FAIR PROJECT

Yellow:

Sunlight:

Purple:

Sources of Error:

• similar growth rates as red/orange
• pigments absorb as much purple as red or orange
• shorter wavelength yet not higher absorption
• too much energy for the plant so it needed to restrict some of the energy

• slowest growth rate w/ lightbulb: no pigments absorbed any yellow wavelengths
• yellow is also reflected from plants: why they are yellowish green
• evolutionarily, there is probably not enough yellow light in most light sources (does not have the QUALITY nor the QUANTITY)
• plants evolved to absorb less

• slowest growth by far: hardest to control
• weather: affected amount of sunlight / day
• time: duration of light changed every day, as well as differed from other plants
• temperature: temp in boxes controlled, temp of sunlit plants depends on time and temp of room (effect on photosynthesis)
• intensity: sun changes position rel. to plants throughout the day so diff amounts of light at diff times of day

• Human error (incorrect measurements in procedure and observations)
• Cellophane paper for orange/purple
• box problems (hole in the flaps, distance from light to the plants)
• the sunlit plants

How Does Colored Lights

Affect Plant Growth

By:

Arnaud Ndonue

Akil Woods

Gaston Yobol

Period: 2B Intergrated Sciences

Materials

"When electric sources produce light, the wavelength is influenced by many things. For instance, a tungsten filament in an incandescent bulb emits more light with long wavelengths (the reds) when it is relatively cool, and more short wavelengths (the blues) when it is relatively hot."

Vandre, Wayne. "Fluorescent Lights for Plant Growth." University of Alaska Fairbanks. Cooperative Extension Service, n.d. Web. 24 Apr. 2013. <http://www.uaf.edu/files/ces/publications-db/catalog/anr/HGA-00432.pdf>.

References

Conclusion:

Chlorophyll --> inside the photosystems with other accessory pigments. These catch the light to be used in photosynthesis.

• The hypothesis was proved wrong
• The purple light had slower growth rate than blue light, the yellow had slower growth rate than the red.
• The hypothesis did not take quality into account: higher QUANTITIES of red and blue.
• The blue & white lights: most beneficial for plants to grow under
• The yellow & green lights: least beneficial for plants, why they are reflected by chlorophyll.

The two main factors of light that can affect photosynthesis are:

Quantity (number of photons)

Intensity/Duration

Quality (wavelength)

Product: amount of energy

• 48 plastic cups filled w/ soil and 1 ungerminated sugar snap pea seed per cup
• 6 cups per box, 7 boxes with a red, orange, green, blue, purple, or white light hanging above connected to a timer to turn on and off at the same time each day
• 6 sunlit plants, try to give these same light quantity as others
• 1 tablespoon of water every day at the same time per cup for 21 days after the first plants start growing
• measure the plants' stems in cm at the same time every day

Jackie D. "Requirements for Plant Growth." Requirements for Plant Growth. N.p., 18 July 2012. Web. 05 Feb. 2013. <http://www.aces.uiuc.edu/vista/html_pubs/hydro/require.html>.

"AZ Master Gardener Manual: Environmental Factors." AZ Master Gardener Manual: Environmental Factors. The University of Arizona, 1998. Web. 04 Feb. 2013. <http://ag.arizona.edu/pubs/garden/mg/botany/environmental.html>.

Danielle Dunn, edublogs, 2011. Web. <http://dedunn.edublogs.org/2011/06/08/chlorophyll-and-absorption-of-light/>.Butler,

Madigan, Jay. "What Wavelength Goes With a Color?" What Wavelength Goes With a Color? National Aeronautics and Space Administration, n.d. Web. 06 Feb. 2013. <http://science-edu.larc.nasa.gov/EDDOCS/Wavelengths_for_Colors.html>.

"Light and Color @ The Franklin Institute." Light and Color @ The Franklin Institute. The Franklin Institute, n.d. Web. 06 Feb. 2013. <http://www.fi.edu/color/color.html>.

Raven, Peter H. "How Plants Grow in Response to Their Environment."Http://www.mhhe.com/biosci/genbio/raven6b/graphics/raven06b/other/raven06_41.pdf”. McGraw-Hill Higher Education, Jan. 1996. Web. 2 Feb. 2013.

Miller, Ken. "Photosynthesis: Introduction." Photosynthesis: Introduction. Pearson, n.d. Web. 07 Feb. 2013. <http://www.phschool.com/science/biology_place/biocoach/photosynth/intro.html>.

Richard E. Barrans Jr., Ph.D; Argonne National Laboratory, 2012. Web. <http://www.newton.dep.anl.gov/askasci/phy99/phy99523.htm>.

Procedure:

Hypothesis

Thesis

The experiment will be looking at the

differences in rates of sugar snap

pea plant growth using different

color light sources, and analyzing the

results and determining the best light

color for fastest pea plant growth.