Devernalization:

Ø If vernalized seedlings or seeds are subjected to higher temperatures like 35-40 0C the plants that develop from such treatment fail to flower. Such a nullifying effect by higher temperatures is called Devernalization.

Ø Nevertheless, if the vernalized plants are maintained at sufficiently low temperatures for a long period, which has to be determined for every species, devernalization is not possible. This may be due to the putative vernalin having already acted upon the genetic material and committing it is flower formation.

Ø However, devernalized plants can be vernalized by subjecting the same seedling or seed against another period of cold treatment by repetition of vernalization and devernalization cycles. Prolonged vernalization the effect decreases and seedlings lose their viability and potentiality to produce flowers.