If you are interested in growing plants in a greenhouse, you may have discovered the concept of Photosynthetically Active Radiation (PAR) and its significance to photosynthesis in plants. PAR is measured over a wavelength band of solar radiation from 400 to 700 nanometers, which corresponds to the absorption spectrum of chlorophyll for the process of photosynthesis.

PAR is measured from the light incident on the plants, so PAR values are based on light sources such as the sun. If you have a greenhouse, the greenhouse has clear or translucent panels between the incident sunlight and the plants. These panels will reduce the PAR energy, so you should pay attention to the transmission characteristics of the panels over the 400 to 700 nanometer PAR bandwidth.

We reached out to consultants who work on PAR measurements and calculations for applications in agriculture and forestry. We shared our TUFTEX optical transmission measurement data and received PAR values based on two phases of natural daylight: CIE D50 and CIE D75. The CIE D series of illuminants represent natural daylight from D50 to D75, so our two references cover the range of natural daylight to which plants are exposed.

We are pleased to share with you that the TUFTEX PolyCarb Clear panels transmitted 89% of the PAR energy for CIE D50 and CIE D75 daylight. This is a very good result that shows the TUFTEX PolyCarb Clear panels are well suited for greenhouse use.

More information about Photosynthetically Active Radiation (PAR) is available at wikipedia.org.

More information about the CIE D series of illuminants is available at wikipedia.org.