ABSTRACT
Solar radiation is the main source of heat energy to the biosphere. Tem perature is the intensity aspect of heat energy, and it is of paramount impor tance for organic life. Temperature governs the physical and chemical pro cesses that in turn control biological reactions within plants. It controls the diffusion rate of gases and liquids within plants, and solubility of plant nu trient substances is dependent on temperature. As such, environmental tem perature has a primary role in plant growth and its geographical distribution over the earth.
