PAR and Visible Light Spectrum- The spectrum of light that is visible to the human eye is approximately 380-780 nm (nanometers). Interestingly, plants also use almost the same spectrum of light visible to the human eye. This part of the electromagnetic radiation, which powers photosynthesis, is named PAR (Photosynthetically Active Radiation) and is usually found in wavelengths from 400 to 700nm. PAR is often confused as a type of measurement, but is more the designation of a region of light within the spectrum that is usable to plants.
PPDF- (Photosynthetic Photon Flux Density) is a measurement that is very important to your plants. Unlike lumens which will only measure the brightness of a light source, PPFD measures the number of photons within the PAR region that reach the target each second. Simply put, a PPFD measurement will tell you how much necessary light (within the PAR region 400-700nm) is actually making it to your plant.
The beam heat from HPS will raise the temperature in the top of the greenhouse. This heat will circulate to the temperature sensor, which will close / reduce the bottom heat. This results in “cold roots”, which affects the crop’s growth. To avoid this situation, the windows open, temperature is dropping and allowing the temperature sensor the opportunity to open the bottom heat. As a result, the open windows will cause loss of heat and CO2.
At a working temperature at only 45°C for the Senmatic LEDs, the climate condition for the crop is significant more comfortable. Bottom heat can be active under all conditions, to secure active roots and resulting in optimum growth conditions. The significant lower working temperature of the LED fixtures allows less ventilation and protect heat and Co2 loss, too.
Green light is considered the least efficient wavelength in the visible spectrum for photosynthesis, but it is still useful in photosynthesis and regulates plant architecture.
The majority of green light is useful in photosynthesis. The efficiently plants use wavelengths between 300 and 800 nm. Green light is the least efficiently used color of light in the visible spectrum.
One potential advantage of including green in a light spectrum is to reduce eye strain of growers. Under monochromatic, or sometimes two colors of light such as blue and red, plants may not appear their typical color, which could make noticing nutritional, disease or insect pest issues difficult. Another potential advantage of green light is that it can penetrate a canopy better than other wavebands of light. It’s possible that with better canopy penetration, lower leaves will continue to photosynthesize, leading to less loss of the lower leaves.