Plant Physiology

Photosynthetically Active Radiation (PAR) refers to the portion of the sunlight spectrum (400-700 nm) that is used by plants for photosynthesis. Although sunlight is abundant, plants are able to capture only a small fraction of PAR effectively. Studies indicate that only about 2-10% of the PAR available to plants is converted into chemical energy through photosynthesis. The rest of the energy is either reflected, transmitted, or dissipated as heat.