How does colored plastic wrap affect plant growth?

Answer 1

Blue plastic wrap, of course, reflects blue light, so putting you plant under blue plastic wrap denies the plant of that wavelength.

Now the majority of light that the sun gives out is yellow, so it only makes sense that plants have evolved to maximize their exploitation of that particular wavelength. As a consequence green light has been sacrificed as that is the colour that chlorophyll (the yellow exploiting pigment) reflects. Even though green light has more energy than yellow there is less of it so it is favourable for the plant to go for the yellow as the over-all sum of the energy it receives by this method is higher.

Now chlorophyll reflects green but does absorbs higher blue and violet. These wavelengths are very high energy and even though there isn't very much of them they are capable (due to their high energy quantum) to drive reactions that yellow light cannot. For this reason there are a few photosynthetic reactions that the plant uses blue light for to make rare but important compounds.

So by putting your plant under blue plastic wrap you are denying the plant the production of rare but important compounds, which it now has to obtain by so other less productive means.

Answer 2

Using green plastic wrap can cause a plant's growth to suffer. This is because it reflects green light and absorbs other colors.?æ