What do you understand by vernalisation? Write its significance.

i) The method of inducing early flowering in plants by pre-treatment of their seeds or young shoots at low temperature is called vernalisation.
ii) Significance:- Certain plants require a low temperature treatment during early stages of the life for subsequent flowering in the later stages if not, they fail to flower.
Ex:- (i) Some food plants such as wheat, barley and ryehave two kinds of varieties. Winter varieties if planted in spring season cannot yield grains until second year due to lack of exposure to cold temperature during its early stages.
Ex:- (ii) In biennials like cabbages, sugar beet, carrots flowering may be induced in the same season by meeting their temperature requirement.