Greenhouse requires certain amount of lights for particular time period depends on plants,
if this can’t be done naturally then we have to provide supplementary lighting.
Supplemental lighting is the use of multiple, hight intensity light source to promote plant
growth.
Supplemental lighting is used in greenhouses to increase crop production during time
periods with low levels of solar radiation. These time periods usually occur during the
winter months and during the cloudy time in rainy season.
For long day plants sometimes, we have to give very low light intensity for longer duration
such type of lighting is called photo- periodic lighting.