Plant Growth & Light Color

Is plant growth affected by the color of light?

Question: I need help with an experiment I'm doing. I read some place that plants need more red artificial light because it is the color of heat. It also said that artificial blue light was a cool color.

Plant Growth and Light Color- Some Answers from Others

Jenni (a former student of SAS, a China located international school):
The color of light does affect plant growth. See, sunlight contains many colors of the visible specturm, and the invisible. Plants can be affected. Cellophane tents don't work because they don't supply the correct amount and cellophane affects opaqueness of the light... so use colored light bulbs. Plants (expecially flowering and house) tend to like violet, blue and red lights... not so much as some yellows, oranges and greens. Maybe this should help... Good LUCK!!!! -Jenni,
Here are a few sites to help, as well:
Does Colored Light Affect Seed Growth
How Light Affects Plant Growth

Mac:
John Ott worked a great deal with plants and how light and color affects them. I suggest you read some of his work. You can find references to John Ott on the web. I suspect it's not the color 'temperatures' you'll find to be central, but the frequencies of light that come in contact with the plants. You can do literature searches on such topics as color, temperature, and plants. But conducting an experiment gives you direct experience and first hand observations. That's what scientists like! :-) Conduct your own experiment - and maybe you'll find something never before discovered.

The 'color' of light (the emission amplitude and spectral distribution) can significantly affect plant growth. Keep in mind, it's not only the visible light, but the UV and infra-red areas in the spectrum - light that is not visible to the human eye. There are 'full spectrum' light bulbs that have been available (at least in the past) for people who wish to provide 'sun equivalent' lighting forplants [and people too] - both plants and people probably grow better :) under this type of balanced light. As an aside, the typical cool white fluorescent lamp emits strongly in the blue and green emission bands (try peeking at one with a prism or spectra scope.) Studies have suggested that fluorescent and other unbalanced bulbs do less than great things of people and plants are exposed to them chronically (prolonged exposure).....including 1. increased incidence of dental caries (cavities), 2. hyperactivity and depression in adults...on and on... To answer your question though, yes, light affects plants. It can inhibit growth, reproduction, and plant health.. ...or help it if the light is right. Regards, Mac

AMC:
Find a few books written by John Ott. He did some plant and colored light stuff - kinda like you are! :) Cool eh? Then - don't believe everything you read. Do the project yourself! Get some plants, buy some little lights, and away you go. (Psst - go ahead and do the Red, Blue, White, and Yellow - but add a few more lights if you can. A so-called Gro-Light that has some UV in it - and perhaps a standard fluorescent bulb.)

Links to More Science Projects

Here's a compilation of all the pages with information from students who are conducting scientific color experiments.

Color and Heat Absorption

Does Color Affect Taste?

Color and Water Evaporation