“Importance of High Light Transmission”
When it comes to light and growing plants in a greenhouse, growers are concerned with light intensity (brightness), light quality (color/whiteness), light duration (daylength), and the ability for light to reach the plants. The amount of light transmittance coming into a greenhouse is one of the most important factors affecting plant growth and crop production.
When light transmission is deficient or drops below a minimum intensity, plants may fall below their compensation point. (A plants compensation point is the metabolic point at which the rates of photosynthesis and respiration are equal so that leaves do not gain or lose dry matter.) If this happens, photosynthesis slows down or ceases while respiration continues, greatly impacting plant growth, development, and yield.
Greenhouse covering materials have various light transmission values. Compared to glass, acrylic, and PE films, multiwall polycarbonate offers the greenhouse grower the ideal combination of high light transmission, thermal insulation, impact strength, and energy efficiency in a lightweight sheet.
Since light transmission plays such a significant part in greenhouse growing, understanding the performance characteristics of the different manufacturer’s polycarbonate panels is very important.
Polycarbonate warranties address how much light transmission a panel will lose over a period of time. The higher the percentage, the more light transmission is lost. Loss of light transmission has a significant impact on the functionality of a polycarbonate panel, especially in plant growth applications.
The rule of thumb is that for every 1 % of light transmission, there is a 0.75% – 1% loss of crop yield.