Photoperiodism

Photoperiodism
Definition
The length of daily period of light to which is exposed is called photoperiod and the response of plant to the photoperiod is called Photoperiodism.
OR
The influence of relative lengths of day and night on the activities of an organism is called Photoperiodism.
Types of Plants on the Basis of Photoperiodism
On the basis of their differing responses to light and dark, flowering plants can be divided into three groups.
1. Long Day Plant
2. Long Day Plant
3. Day Neutral Plant
1. Long Day Plant
Those plants which required long days and short nights are called long day plant.
Examples
Petunias, Spinach, Radishes, Lettuce etc.
2. Short Day Plant
Those plants which required short days and long nights are called short day plant.
Examples
Chysanthemums, Cocklebur, Poinsettias etc.
3. Day Neutral Plant
Those plants which are in different to day length are called day neutral plant.
Example
Tomato and Cotton etc.