![]() ![]() Therefore in 2004 the product ReduHeat was developed, which separates the radiation of PAR light and infra red. ReduSol causes the largest amount of heat reflection but this coating also reflects a relatively large amount of light. They can be applied to the roof for the months that infrared radiation is not needed and removed again when heat becomes beneficial again. With some crops, such as chrysanthemum and gerbera, flower colour can be improved by avoiding over-heating.Ĭoatings are a very good way to keep out NIR-radiation. In this way you retain more CO 2 in the greenhouse which results in more growth. Then the crop transpires less so the window vents can be closed for longer. ![]() The combination of lots of light, a high crop temperature and low humidity leads initially to a halt in photosynthesis and eventually to actual damage.Įven before the plant approaches the fatal range it can be very useful to limit the rise in plant temperature. This is beneficial to all kinds of plant processes. Within a certain range, it is of course positive that the crop warms up. In general, the plant temperature will be higher than that of the greenhouse air. On such a day the plant temperature heats up more than the greenhouse air. Furthermore, the crop and the greenhouse equipment that have absorbed radiation also heat the greenhouse air. Therefore on a nice sunny day the crop, which after all is for the most part made up of water, warms up considerably. Blue, green, red and far red pass straight through water but infra red heats it up, especially above 1200 nm. The plant is warmed due to the properties of water. Yet screening does prevent excessive warming. The plant does not use infrared for photosynthesis, so there’s no disadvantage to screening it out. From 700 to 2500 nm it is called near infrared (NIR), also known as shortwave radiation.Ībove that is long wave radiation. All radiation above a wavelength of 700 nanometres (nm) is called infrared and so it begins above the red light. ![]()
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