which of the following statements are correct regarding short day plants?

1. they flower when night length is longer
2. they are the same as long as day plants
3. they do not have a critical photoperiod
4. all of these are correct

Short-day plants flower when the night lengths exceed their critical photoperiod. They cannot flower under short nights or if a pulse of artificial light is shone on the plant for several minutes during the night; they require a continuous period of darkness before floral development can begin. Natural night time light, such as moonlight or lightning, is not of sufficient brightness or duration to interrupt flowering.