Question

Short day plants flower

• A. When night exceeds a critical photoperiod.
• B. When dark period is interrupted by flash of light
• C. When the night length is shorter than critical period
• D. When the night length is shorter than a critical dark period but the day length is interrupted with a short dark period

Answer 1

The correct option is A

When night exceeds a critical photoperiod.

The correct option is A:

Explanation of the correct option:

1. Short-day plants can only flower if the day length is less than 12 hours.
2. They prefer long nights and short days for flowering.
3. It is critical for them to have an uninterrupted dark period to flower.

Explanation of the incorrect option:

Option B:

Short-day plants cannot flower even if there is a pulse of artificial light shining on the plant for a few minutes.

Option C:

Night length has to be longer than the critical period for the short-day plants to flower.

Option D:

They require a continuous uninterrupted long night than a critical photoperiod to flower.

Final answer: when night exceeds a critical photoperiod.