Nicotiana tabacum, a Short Day Plant, when exposed to more than critical period of light fails to flower. Explain.

Short day plants need a prolonged dark period to flower because during this time all the chemical transformations occur in the plant which aids in the flowering of the plant. It requires a short day exposure to light in order to flower but beyond a certain point when exposed to more than the critical period of light, short day plants will not be able to flower. So Nicotiana tabacum being a short day plant is unable to flower because of the above stated reasons.