Radiant energy Biological clock 1 Carbohydrate synthesis 1 Carbon Dioxide Fixation 1 Ecology 1 Environment 1 Environmental physiology 1 Enzymes 1 Hormones and growth 1 Lipids 1 Osmosis 1 Photomorphogenesis 1 Photoperiodism 1 Photosynthesis 1 Plant Physiology 1 Plant biochemistry 1 Proteins 1 Stress physiology 1 actinometric measurement radiation-absorption 1 radiation-deffuse 1 radiation-global radiation-thermal 1 radiation-scattering radiation-direct solar 1