What Type of Plants Flower Only If Day Length Is

Question

What type of plants flower only if day length is less than a critical value?
A) short-day plants
B) long-day plants
C) biennial plants
D) perennial plants

Accepted Answer

Short-day plants require a day length shorter than a critical value (usually around 12 hours) in order to flower. These plants include crops like soybeans, peanuts, and cotton. Long-day plants, on the other hand, require a day length longer than a critical value to flower (usually around 14-16 hours), and biennial and perennial plants can have different requirements depending on the specific species.