Growth and Development of Horticultural Crops (1+1)

Importance of photoperiodism

• The knowledge of the phenomenon of photoperiodism has been of great practical importance in hybridization experiments. Although the floral hormone ‘florigen’ has not yet been isolated, the isolation and characterization of this hormone will be utmost economic importance.
  
• The phenomenon of photoperiodism is an excellent example of physiological preconditioning (or after-effect) where an external factor (i.e., the photoperiodic stimulus) induces some physiological changes in the plant the effect of which is not immediately visible. It lingers on in the plant and prepares the latter for a certain process (i.e., flowering) which takes place at a considerably later stage during the life history of the plant.