$Nicotiana$ $tabacum$,a short-day plant,fails to flower when exposed to a light duration longer than its critical period. Explain.

(N/A) Short-day plants are those that flower only when the photoperiod (duration of light exposure) is shorter than a specific critical duration. Since $Nicotiana$ $tabacum$ is a short-day plant,it requires a light period shorter than its critical threshold to initiate the flowering process. When exposed to light for a duration exceeding this critical period,the physiological conditions required for floral induction are not met,thus preventing flowering.