The effect of daily light or day length on the flowering & fruiting of the plants is called as photoperiodism. The term photoperiodism was first used by Garner & Allard (1920). On the basis of daily light required for flowering, the plants are of three types-
- Long day plants (LDP)
- Short day plants (SDP)
- Dav natural plants (DNP)
On the basis of requirement of light, the plants are of two types-
- Photophilous or Heliphelous or Heliophytes –
The plants which need bright light to grow. Examples – Sun flower, Ameranthus, Populus etc.
- Sciophilous or Sciophytes –
The plants which grow in less light or shadow. synthesis of anthocyanin pigment in plants. The purple sulphur bacteria use infra red & UV radiations for photosynthesis.
