Question

In short-day plants, flowering is induced by 

(a) Photoperiod less than 12 hrs 

(b) photoperiod below a critical length and uninterrupted long night 

(c) long night 

(d) short photoperiod and interrupted long night

Answer 1

The correct option is (b) photoperiod below a critical length and uninterrupted long night.

Explanation:

In short-day plants flowering is induced when the day length do not exceed a certain critical value, the day length required is less than a certain critical length. Short-day plants may be more correctly called long night plants as a certain minimum of uninterrupted dark period in 24 hrs is necessary for their flowering. Short-day plants will not flower if the dark period is less than a critical length.